Smithiana, Publications in Aquatic Biodiversity, Bulletin 7, May, 2007, pp. 15-49
Electrolux addisoni, a new genus and species of electric ray from the east coast of South Africa (Rajiformes: Torpedinoidei: Narkidae), with a review of torpedinoid taxonomy
Leonard J.V. Compagno1 and Phillip C. Heemstra2
1 Shark Research Centre, Iziko-South African Museum, Cape Town, South Africa,
(Submitted 7 December 2006; accepted 23 February 2007)
Code Number: sm07003
A new genus and species of sleeper ray, Electrolux addisoni (Family Narkidae), with two dorsal fins is described from two adult males (total lengths 50 and 52 cm) caught on a shallow reef off the east coast of South Africa. Electrolux is distinguished from other genera of Narkidae by its prominent spiracular papillae, the morphology of its nostrils, nasal curtain, mouth, jaws, chondrocranium, basibranchial skeleton, pectoral and pelvic girdles, and unique and complex colour pattern. It has higher vertebral, pectoral radial, tooth and intestinal valve counts than other narkids and reaches a greater size than all species with the possibly exception of Typhlonarke aysoni. Taxonomic definitions are provided for the electric rays, for the family Narkidae, and for Electrolux, as well as keys to families of electric rays and to the genera of Narkidae. The systematics of the narkid genus Heteronarce is reviewed and the genus validated. Members of the Narkidae may include the smallest, or at least the shortest, living chondrichthyans (Temera hardwickii and an undescribed species of Narke). Electrolux addisoni is a reef-dweller that eats polychaete worms and small crustaceans, and has been photographed and videotaped by divers while actively feeding in the daytime. The conspicuous dorsal colour pattern may be aposematic, as the ray was seen to make a possible threat display when closely approached. Electrolux addisoni is recorded from four localities along an approximately 310 km. strip of coastline from Coffee Bay, Eastern Cape Province, to just north of Durban, kwaZulu-Natal inside the 50 m isobath. This conspicuous, active ray is known only from a few diver records from reefs reported over approximately two decades, and its conservation status needs to be critically assessed.
KEY WORDS: Electrolux addisoni, new genus and species, Narkidae, sleeper ray, Torpedinoidei, description, taxonomy, distribution, biology, conservation status.
The coastal fish fauna of the east coast of South Africa is a mixture of tropical and subtropical Indo-West Pacific fishes (mainly coral-reef species), many endemic warm temperate species, and several worldwide species. This South African fish diversity is not well known, and in the past 20 years, our cursory fish survey work has produced numerous range extensions, many new records and several new species. In addition to our own collecting efforts and those of fisheries biologists on South African research vessels (particularly RV Africana; see Compagno, 1999b) and fishing companies and observers on fishing vessels, our knowledge of the South African marine fish diversity is significantly enhanced by the specimens and photographs provided by various amateur ichthyologists (anglers, aquarists, divers and underwater photographers).
This paper describes a remarkable new genus and species of electric ray (Family Narkidae) from the east coast of South Africa. The species was first made known to us by diver-photographer Peter Chrystal (through Rudy van der Elst, pers. comm.), who photographed this spectacular ray on a patch of sand on Aliwal Shoal, kwaZulu-Natal, South Africa in 1984 (Figure 1). The ray was subsequently rediscovered on Protea Banks off Shelly Beach, kwaZulu-Natal in 1997 by underwater photographers Stephania and Peter Lamberti (pers. comm.) who sent us a video-clip of the ray (Figure 2). It has also been photographed underwater at the Tee Barge north of Durban by Dennis King. A live specimen was seen underwater by P. Heemstra at Coffee Bay, Eastern Cape in 2001, but the ray fled before he could net it.
From the 1984 photographs we immediately recognized an undescribed species of electric ray (Torpedinoidei or Torpediniformes) with a unique dorsal colour pattern that was far more elaborate and ornate than that of any electric ray known at the time, although Last & Stevens (1994) and de Carvalho (1999) subsequently described species of Narcine off Australia and in the Western Hemisphere with ornate but simpler colour patterns. The ray was tentatively considered as either a member of the family Narkidae or Narcinidae by Compagno (in Smith & Heemstra, 1995) but after video footage became available, Compagno (1999b) thought it to be an undescribed narkid most probably of the genus Heteronarce because of its general morphology and twin dorsal fins.However, the ray frustrated us by eluding capture for nearly two decades despite efforts by colleagues to collect it. In September 2003 a specimen (SAIAB 78777) was collected by Mark Addison on a reef off Manaba Beach near Margate in southern KwaZulu- Natal. A second specimen was collected by Mark’s father, Brent Addison at the same locality in October 2003. Both specimens (Figure 3, 4) were presented by Mark Addison to the South African Institute of Aquatic Biodiversity and the second specimen was transferred to the fish collection of Iziko - South African Museum (SAM 36908).
Study (including radiography) of the two specimens and dissection of the paratype (SAM36908) confirmed our hypothesis that they represented a new species of the Family Narkidae (sleeper rays), which in South African waters also includes the common onefin electric ray, Narke capensis and the rare Natal electric ray, Heteronarce garmani (Compagno in Smith& Heemstra, 1986, Compagno et al., 1989). However, this new electric ray proved sufficiently different from known narkid genera Heteronarke, Narke, Temera and Typhlonarke to warrant a new genus and species (Compagno, 2005). We also discuss the systematics of Heteronarce and the Family Narkidae, and the taxonomy of electric rays, and comment on the size of narkid rays and the biology, habitat and conservation status of the new ray
EXTERNAL MORPHOLOGY AND MORPHOMETRICS: Terminology and abbreviations for torpedinoid external morphology and morphometrics are based on Bigelow and Schroeder (1953) for batoids, Compagno & Roberts (1982, 1984) for stingrays, and Compagno (1984, 1988, 2001) and Compagno et al. (2005) for sharks. Measurements and their abbreviations for electric rays are based on the system for sharks in Compagno (1984, 2001) with some modifications and additions. For the bases of precaudal fins the term origin is used for the anterior end of the fin base and insertion for the posterior end of the base. The morphometric abbreviations and definitions for torpedinoid measurements are presented below (Fig 1). Meristics. Terminology and abbreviations for torpedinoid vertebral counts is derived from that for sharks in Compagno (1988) and for stingrays in Compagno & Roberts (1982, 1984) and are defined as follows: SYN, total synarcual vertebrae; sum of SYC, synarcual segments anterior to synarcual centra and determined by count of neural canals through lateral walls of synarcual, and SYC, synarcual centra in posterior end of synarcual. MP, monospondylous precaudal centra, between posterior end of synarcual and monospondylousdiplospondylous transition, sum of MPN, monospondylous precaudal centra without ribs, and MPR, monospondylous precaudal centra with ribs. DP, diplospondylous precaudal centra, between MPDP transition and upper origin of caudal fin; sum of DPN, diplospondylous precaudal centra without ribs, and DPR, diplospondylous precaudal centra with ribs. DC, diplospondylous caudal centra from upper origin of caudal fin to end of vertebral column. PC, precaudal vertebrae, including SYN, MP, and DP vertebrae. PCC, precaudal centra, including SYC, MP, and DP centra. TF, total free centra from posterior end of synarcual to end of caudal centra; sum of MP, DP, and DC centra. TC, total free centra plus synarcual centra; sum of SYC, MP, DP, and DC. TS, total segments, all centra plus SYS. SYN %, total synarcual centra as percentage of total free centra, 100*(SYN/TC). MP%, monospondylous precaudal centra as percentage of total free centra, 100*(MP/TC). DP%, diplospondylous precaudal centra as percentage of total free centra, 100*(DP/TC). DC%, diplospondylous caudal centra as percentage of total free centra, 100*(DC/TC).
Tooth and intestinal valve terminology and count methodology is after Compagno (1988).
Terminology and information on torpedinoid anatomy including chondrocranial and hyobranchial morphology follows Henle (1834), Gill (1862), Haswell (1895), Garman (1913), Holmgren (1941), and Compagno (1973, 1977, 1988, 1999a). Clasper terminology for torpedinoids follows Leigh-Sharpe (1922, 1924, 1926) and Compagno (1988).
ORDER RAJIFORMES, SUBORDER TORPEDINOIDEI - ELECTRIC RAYS
DEFINITION (derived from Compagno (1973, 1977, 1999a). Rays (Rajiformes) with head broadly depressed and included with body and hypertrophied pectoral fins to form a thick, flattened, oval, circular or subquarate fleshy pectoral disc with broadly rounded apical margins. Trunk thick, broad, and depressed, not rising abruptly dorsal to pectoral bases. A pair of large, kidney-shaped electric organs in disc between propterygium, branchial region and pectoral girdle, generally visible through skin of ventral surface. Precaudal tail usually stout and muscular, more or less elongated, but diminutive in Hypnidae; tail with two, one or no dorsal fins, ventro-lateral folds (often present) but nomedian dorsal or ventral skin folds; tail without caudal electric organs or a sting. Preoral snout short to moderately long, 6-21% of total Total length, broadly rounded or truncated, front edge continuous with that of the pectoral disc and not angular, not formed into a tooth-studded rostral saw. Eyes small to moderate-sized in most taxa (eyes vestigial in some Narke dipterygia and absent externally in Typhlonarke) dorsal on the head, well medial to lateral margins of disc and anterior to spiracles; eyes with a velum on the cornea but no semilunar groove below them. Spiracles either contiguous with rear margins of eyes or separated from them by a space less than their width; spiracles with internal pseudobranchs. Nostrils moderately large, close together, just anterior to mouth; circum-narial flaps and grooves well developed on incurrent apertures of nostrils; anterior nasal flaps fused medially to form a broad nasal curtain, which is free posteriorly and usually reaches mouth; broad nasoral grooves present between excurrent apertures of nostrils and mouth. Mouth always subterminal on head although varying in position (close behind front edge of snout in Electrolux), small to moderate-sized, straight or arcuate. No gill sieves or rakers on internal gill slits. Teeth small and not fused into crushing plates; dental bands limited to medial half of jaws, not extending to mouth corners; teeth in 8-68 / 7-75 rows, total rows 15- 141; tooth crowns carinate, monocuspidate or tricuspidate. Skin completely naked on all surfaces of disc, tail, fins, and claspers. Pectoral fins expanded, fused medially with head and trunk, usually not obviously distinct externally; pectoral fin bases very long, extending from nasal capsules to pelvic fin origins; pectoral axils much closer to vent than to first gill apertures. Propterygia of pectoral fin skeleton greatly elongated, longer than metapterygia, segmented anteriorly and forming a propterygial axis; propterygia reaching level of nasal capsules or ending behind them, radials extending in front of nostrils but not reaching snout tip. Mesopterygia large and expanded anterolaterally to opposite posterior quarter to half of basal segment of propterygial axis, and carrying its radials. Scapulocoracoids with a pair of lateral bars connecting coracoid bar with scapular processes on each side, separated by a large fenestra from lateral face of scapulocoracoid, which forms unique hollow tube, more or less elongated posterolaterally and terminating in a small, roundedoval articular surface with a distinct procondyle for the propterygium, small anterodorsal and anteroventral foramina above and below a broad anterior bridge between the procondyle and a small mesocondyle for the mesopterygium, small postdorsal and postventral foramina, and a moderate-sized metacondyle for the metapterygium. Suprascapulae fused together above synarcual or behind it and above neural spines of free monospondylous vertebrae; suprascapulae without the complex attachment to vertebral column as in other batoids; distal ends of suprascapulae straight and not forked, articulating with scapular processes. Pelvic fins not divided into distinct anterior and posterior lobes (except in Typhlonarke, where the anterior lobes are fused with and protrude from the pectoral disc and the posterior lobes are fused to the posterior disc). Origins of pelvic fins anterior to pectoral free rear tips; pelvic fins with straight, convex, or concave posterior margins. Pelvic girdle with strong lateral prepelvic processes, short ischial and iliac processes, but without a medial prepubic process on puboischiadic bar; puboischiadic bar posteriorly arched or transverse, not anteriorly arched. Claspers short, stout, and protruding a short distance past pelvic free rear tips or not at all in adult males; clasper glans very simple, with small pseudosiphon and pseudopera but without clasper spines. Dorsal fins usually two (one in Narke and Typhlonarke, absent in Temera), moderately large (small in Hypnidae) and rounded-angular (not falcate). First dorsal fin when present with base over or just behind pelvic bases and over anterior half of precaudal tail. Caudal fin usually large to moderate-sized (small in Hypnidae); caudal fin vertebral axis horizontal to weakly diagonal and elevated, diphycercal or weakly heterocercal; dorsal and ventral caudal fin margins broadly rounded, terminal lobe mostly rounded or occasionally pointed, a low ventral caudal lobe present or absent; caudal fin without a differentiated postventral margin and without a discrete terminal lobe and subterminal notch. Vertebral column with cervicothoracic synarcual but no thoracolumbar synarcual; synarcual variable in length, ending before or behind suprascapulae; synarcual not formed anteriorly into a collar-like sheath around spinal cord but with a peglike ventral projection fitting in foramen magnum and between occipital condyles. Cranium with rostrum variably developed, absent (Hypnidae), more or less reduced (Torpedinidae, Narkidae) or moderately large, wide, and trough-shaped (Narcinidae). Precerebral cavity more or less expanded into rostrum but not roofed dorsally, truncated anteriorly in Narkidae. Rostral nerves not enclosed in rostrum.
Nasal capsules expanded laterally, ventrolaterally, ventrally or anteroventrally; internasal septum broad and depressed (Narcinidae) to more or less narrow and compressed (Hypnidae, Narkidae), broadly separating the nasal capsules or not. Antorbital condyles on anterior, lateral or posterior surfaces of nasal capsules; antorbital cartilages distally expanded, directed anteriorly or anterolaterally, fan-shaped or antler-shaped and branched; antorbital cartilages not articulating with propterygia. Preorbital processes rudimentary or absent, no supraorbital crests, no postorbital processes and no low suborbital shelves. Anterior fontanelle not delimited anteriorly by a transverse ridge. Cranial roof with frontoparietal fenestra absent or very small to huge; separated from anterior fontanelle by an epiphysial bar or not. Basal plate flat or arched and without basal angle; basal plate with a single internal carotid foramen or two narrowly separated carotid foramina at its midline. Occipital condyles small, ventral, and not covering occiput. Dorsal and ventral labial cartilages present in Narcinidae and Narkidae; absent and presumably lost in Hypnos and Torpedo. Hyobranchial skeleton without basihyoid element; hypobranchials discrete, parasagittal, not fused to form a midventral plate and not fused to well-developed basibranchial copula. Branchial rays expanded distally as broad circular plates.Mode of reproduction ovoviviparous as far as is known, with prenatal young nourished primarily by their yolk sacs
ELECTROLUX COMPAGNO & HEEMSTRA, genus novum.
TYPE SPECIES: Electrolux addisoni Compagno& Heemstra sp nov. described below.
GENERIC DIAGNOSIS: Narkid electric rays with subcircular disc, length 51% TL; snout short, broadly rounded and nearly straight (Figs 1, 2, 3, and 4). Eyes welldeveloped, close to front edge of disc, but mostly hidden by loose skin. Spiracles (Fig. 5) contiguous with eyeballs, rim a low, rounded, ridge with 5 or 6 long, slender stiff papillae and 2 or 3 short, soft papillae, including one minute papilla on eye; spiracle diameter ~ 1.1-1.3 times eye diameter. Incurrent apertures of nostrils nearly circular, flaps of incurrent apertures (circumnarial flaps) broad, large, flattened, trumpetlike and elongated, their length 2/3-3/4 length of anterior nasal flaps; posterior margin of nasal curtain deeply incised, with prominent lateral lobes and a small medial lobe; ventral surface of curtain with a shallow medial groove; length of anterior nasal flap about 1.1 in outer internarial width; lateral margins of curtain nearly parallel. Mouth and nostrils projecting ventrally from disc as a prominent nasoral turret (Figure 6a & 7) near front edge of disc. Lips between labial folds and dental bands thin and with small transverse pleats of skin; lower lip narrow and thin, no mental groove, but ventral dental band bisecting it medially; lower labial folds and grooves short, ending far lateral to midline of mouth (Figure 7); labial cartilages very small, their bases well lateral to symphyses. Total tooth row counts 32-34 or 15-16 / 17-18. Superscapulae C-shaped (Fig 13a), situated anterior to coracoid bar. Total pectoral radials 47-53; metapterygial axis not greatly reduced in length, with equal numbers of radials to propterygium (17-19 each); no neopterygial radials on scapulocoracoid. Pelvic fins not divided into discrete anterior and posterior lobes. Puboischiadic bar with stout angular iliac processes (Figure 14a). Total basipterygial pelvic radials 17-19, Claspers short and extremely flat in adult males (Figure 15), not extending past pelvic free rear tips. Two dorsal fins, subequal in area, second dorsal slightly smaller than first, first dorsal origin over pelvic free rear tips and well behind pelvic insertions. Lateral tail folds broad. Total synarcual segments 14-16, monospondylous precaudal centra 30, diplospondylous precaudal centra, 61- 62, precaudal centra 96-97, precaudal total segments 105- 108, total free centra 118-120, total centra 123-125, total segments 132-136. Neurocranium with a narrow, large, erect, flattened medial rostral cartilage, and two lateral rostral cartilages below it forming a large ventrally-directed yoke-like structure (Fig 9); antorbital cartilages with narrow anterior branched ends (Figs 11 and 12); ethmoid region of chondrocranium laterally compressed, strongly bent and expanded ventrally; no frontoparietal fenestra; otic capsules small and not expanded laterally. Jaws antero-ventro-medially expanded, palatine processes of palatoquadrates nearly straight. Second hyobranchial cartilages large, Intestinal valve count 17 (paratype). Mature males 50-52 cm. TL. Elaborate colour pattern of pale spots on dark brown background present on most of body; dorsal surface of disc of living rays with concentric black lines and pale spots.
Derivation of generic name: The name alludes to the well-developed electrogenic properties of this ray (collectors and photographers have experienced the shocking personality of this bold, active and brightly patterned electric ray first-hand), the discovery of which sheds light (Latin, lux) on the rich and poorlyknown fish diversity of the Western Indian Ocean. And the vigorous sucking action displayed on the videotape of the feeding ray that was taken by Stephania and Peter Lamberti may rival a well-known electrical device used to suck the detritus from carpets, furniture, and other dust-gathering surfaces inmodern homes. The gender of the name Electrolux is feminine.
Comparison with other genera: Electrolux differs from all other narkids including Heteronarce in having large spiracular papillae (Fig 5); very broad, elongated and flattened circumnarial flaps (Figure 6; flaps narrower and usually shorter in other narkids); prominent anterior nasoral turret; narrow thin lower lips without a mental groove (lower lips large and with a mental groove in other genera); small labial cartilages and labial folds ending well lateral to midline of mouth (Fig 7) labial folds enlarged and meeting at midline of mouth in other genera); broad lateral tail folds (tail folds narrow in other narkids and obsolete in Typhlonarke); pectoral radials more numerous (47-53 versus 40-43 radials in other narkids); metapterygia not reduced and radials equal to propterygial radials (metapterygia shorter and their radials fewer than propterygial radials in other genera); claspers not extending past pelvic fin free rear tips (extending past pelvic fin tips in most narkids except Typhlonarke aysoni and some Narke capensis); higher vertebral counts for most vertebral count groups (Table 6); chondrocranium with enlarged medial rostral cartilage and enlarged yoke-shaped lateral rostral cartilages (Fig 9); rostral cartilages small and slender in other genera (as in Figure 10); compressed, ventrally bent and expanded ethmoid region (laterally expanded in other taxa); antorbital cartilages with very narrow branched anterior section (broadly branched in most narkids); palatine processes of palatoquadrates straight, not curved medially; higher intestinal valve counts (17 in Electrolux vs. 8-10 in other genera); greater size (see discussion below); and unique coloration.
Electrolux and Heteronarce are the only narkid genera with two dorsal fins. Two dorsals are primitive for torpedinoids and for batoids, but Narke and Typhlonarke have one dorsal fin in the position of the first dorsal fin of Electrolux and Heteronarce and presumably have lost their second dorsal fins, while Temera has no dorsal fins. Electrolux and Heteronarce also agree in their nearly parallel-edged anterior nasal flaps (nasal flaps more divergent in other narkids, particularly Typhlonarke and Narke ), long and thinner circumnarial flaps (short and thick in other narkids), larger rounded-angular basibranchial copula (copula reduced and tack-shaped in Narke and Temera), and the lack of a frontoparietal fenestra (Narke , Temera, and Typhlonarke with prominent fenestra). nostrils with circular rather than elongate-oval incurrent apertures; a V - shaped posterior margin on its nasal curtain (nearly straight in Heteronarce); short, stout iliac processes on the pelvic girdle (Figure 14a, iliac processes slender, long, curved and attenuated at least in H. bentuvai, H. garmani and H. mollis); and more tooth rows (Fig 4; total 32-34 vs 20-24 in Heteronarce).
Electrolux additionally differs from Typhlonarke in having well-developed eyes (rudimentary in the latter genus and absent externally), a medial groove on its nasal curtain (absent in Typhlonarke), a trilobate Vshaped posterior edge on its nasal curtain (transverse and undivided in Typhlonarke), more tooth rows and smaller teeth (32-34, vs. 15-24 total in Typhlonarke), a stouter precaudal tail, undivided pelvic fins without leg-like anterior lobes, and longer more slender jaws ( jaws short and very stout in Typhlonarke). Electrolux differs from Narke in having shorter iliac processes on its pelvic girdle.
Species: A single known species, Electrolux addisoni Compagno & Heemstra, described below.
Heteronarce? sp. nov. Compagno, 1999b: 116.
Holotype: SAIAB 78777, adult male, 515 mm TL, 305 mm disc width, Indian Ocean on reef off Manaba Beach near Margate, southern KwaZulu-Natal, 30°51.4’ S, 30°23.1’ E; depth 6-12 m; collected by Mark Addison, September 2003.
Paratype: SAM 36908, adult male, 502 mm TL, 291 mm DW, locality the same as in holotype but collected by Brent Addison, October 2003.
DESCRIPTION. Measurements in millimetres and proportions as percentages of total length (TL) are presented in Fig 2 for the types of Electrolux addisoni. Disc subcircular, thick and fleshy; greatest width slightly more (1.1-1.2 times) than its length. Edge of disc a continuous curve, anterior edge nearly straight but broadly curving to sides of disc, with snout, pectoral anterior margins, pectoral apices, and the posterior and inner pectoral margins not distinct but continuously curving rearwards, mesially, and recurving anteriorly to form broad but discrete free rear tips before merging with the sides of tail base. Snout short, preorbital length 6.4-8.2 % TL, preoral length 6.2-8.4 % TL. Prespiracular head length 2.4-2.7 times interspiracular width, preoral length about 1.8- 2.6 times as great as outer internarial width. A pair of small endolymphatic foramina on nuchal region of head about eye-length behind spiracles and about on anterior-posterior line tangent to their inner margins. Electric C- or narrowly kidney-shaped and about three times as long as wide; organs not obvious through skin of dorsal surface but prominent on white medial area of ventral surface; electric organ cells rounded-oval to hexagonal, count of cells for right organ approximately 289 on paratype. Vent anterior to pelvic inner margins and free from them, vent long and with broad lateral folds and conspicuous abdominal pores on the folds of the posterior third of vent. Tail stout, depressed, horizontally oval in cross section, with cutaneous lateral folds (about 7 mm wide) along lower part of tail from above rear end of pelvic fins and below midbase of first dorsal fin to base of caudal fin; tail moderately flattened below folds but broadly convex above; tail from vent to caudal tip about 1.3 times as long as snout-vent length; caudal peduncle nearly flat below folds, narrowly convex above them. Interdorsal space 75-106 % of first dorsal fin base; dorsal-caudal space 70 to 71 % of second dorsal fin base.
Eyes well-developed, protruding above surface of disc, posterior to a transverse vertical plane at mouth; upper eyelids thickened, lower eyelids enlarged and apparently mobile, capable of covering palpebral apertures. Eyeball included in anterior edge of spiracle; dorsal rim of spiracle with 8 slender papillae (Fig 5), their configurations symmetrical between right and left spiracles and arranged as follows: measurements of left spiracle papillae of holotype, followed by lengths of paratype’s papillae in parentheses, first (anterior-most) papilla short, soft, recumbent on top of fleshy orbit, 2.5 mm (2.8 mm); second and third papillae (proceeding clockwise around spiracle rim) cuneate, flattened and stiff, lengths 4.4 (4.5) and 4.7 (3.8) mm respectively; fourth papilla stiff, flattened, resembling a forefinger and short thumb, lengths 6.1 (6.1) and 1.6 (2.0) mm respectively; fifth papilla short, simple, sausageshaped, 2.6 (1.7) mm; sixth, seventh and eighth papillae long, slender, stiff, and finger-like, lengths 4.8 (4.1), 4.2 (3.5) and 8.0 (4.8) mm respectively. The spiracle papillae are bilaterally symmetrical for the left and right spiracles, with the three long, slender papillae on the lateral margins, short fleshy papilla on top of eyes, finger and thumb papilla on posterior rims and two cuneate papillae on medial edges of spiracles.
Nostrils undivided, incurrent apertures with trough- or trumpet-shaped circum-narial folds (Fig 6a, resembling a funnel cut in half vertically and separate from mouth; circumnarial folds somewhat expanded ventrally. Nasal curtain fleshy, elongated, with numerous small pores and a median longitudinal groove or sulcus on its ventral surface; distal (posterior) edge of curtain emarginate and trilobate, with a short, bifid fleshy barbel-like anterior nasal flap at each lateral corner with broadly rounded posterior ends, and a short barbel-like lobe on midline of inner surface ; with mouth closed, the nasal curtain extends over front of lower jaw. Each anterior nasal flap has a strong mesonarial flap above (dorsal to) its posterior tip. Excurrent apertures moderately large, hidden ventrally by nasal curtain and circumnarial folds but open broadly above them to posterior surface of snout in front ofmouth, internarial space between inner ends of excurrent apertures hidden, internarial space about 3.7-4.0 in mouth width when jaws are retracted and mouth closed.
Gill openings small, width of fifth 0.4-0.8 times width of first gill opening and 1.9-2.8 in spiracular length; distance between inner ends of first pair of gill openings about 2.9-3.0 times interspiracular width and about 1.5-1.9 times distance between fifth pair.
Mouth protrusile but scarcely distensible; mouth and jaw tips apparently forming a short tube when protracted and opened; lips thin, transversely-pleated, projecting (Fig 7a) and surrounded by a shallow groove; lips pleated between lateral edges of dental bands and small labial folds; no prominent groove between labial folds, which include labial cartilages at interspiracular distance and 1.5-1.6 times spiracle length.
Tooth bands occupy about half of mouth width, firmly connected to jaw cartilages by connective tissue, band widths greater than inner internarial distance. Teeth in quincunx arrangement, forming a tessellated pavement. Tooth formula 7-8~1~7 / 8~1~8-9, tooth row counts 15-16 / 17-18 rows or 32-34 total rows; ca. 6 - 8 series functional, as indicated by wear on crowns. Teeth very small, similar in both jaws and similar from symphysis tomouth corners, teeth inmidline ofmouth about 1 mm wide across crown foot and lateral teeth slightly smaller; labial surface of crown obliquely flattened, extending lingually as a single small stout cusp (Fig 8) worn-off on most functional teeth); prominent basal ledge and groove on crown; roots small and lingually projecting, divided ventrally by a transverse groove; no teeth exposed on ventral surfaces of jaws when mouth is closed, but dental bands visible along anterior edge of jaws.
Pectoral girdle crescentic in dorso-ventral view (Fig 13). Anterior margin of coracoid cartilage concave medially but convex laterally. Propterygium a narrow segmented axis, articulates with procondyle of lateral face of scapulocoracoid, curves anteriorly, and is divided into 6 axial segments, the distal-most segment poorly calcified; mesopterygium elongated and unsegmented, articulating with the mesocondyle on lateral scapulocoracoid face and runs parallel to proximal segment of propterygium; metapterygium forming an axis of 4 segments, the proximal segment articulates with metacondyle on posterior corner of lateral face of scapulocoracoid and the distal segments extend rearwards into the pectoral base and free rear tip. 17 or 20 pectoral radials on propterygium, 12 or 13 on mesopterygium and 17 or 20 on metapterygium, total radials 46 or 53; no neopterygial radials articulating on lateral face of scapulo-coracoid; distal 2-4 segments of pectoral radials are bifid.
Pelvic fins separate, deltoid-rounded anterior corner rounded, posterior (lateral) edge slightly convex, fairly thick and fleshy, pelvic fin origins well anterior to pectoral fin insertions; anterior edge stiff and thick, supported by the densely calcified anterior radial, apices broadly rounded, posterior (lateral) edge nearly straight or slightly convex when fins are fully spread; free rear tips well-developed, narrow, rounded-subangular, inner margin of pelvics distinct, not attached to sides of tail at free rear tips; no frenum between pelvic inner margins; pelvic fin length ~ 40- 43 % disc width. In live animals the pelvics are often broadly spread and appear rounded rather than angular. Pelvic girdle (puboischiadic bar) broad (Fig 14a), its median antero-posterior width equals one sixth of girdle’s transverse length; prepelvic process at each lateral end of girdle thin and weakly calcified extending anteriorly for the lengths of 7 centra. Iliac processes well-developed on pelvic girdle, expanded dorsally from lateral node, these short, stout, nearly straight, and angular; large basal condyle present on postero-lateral surface of each lateral node for articulation of long pelvic basipterygium, a short but prominent, blunt ischial process present on lateral node medio-posteriorly to basal condyle and mesial to basipterygium. 17 or 19 radials articulating with pelvic basipterygium, plus anterior enlarged radial (apparently a fused double radial) articulating with lateral node of pelvic girdle; the enlarged anterior radial projects postero-laterally and supports the leading edge of the pelvic fin.
Claspers broad, flat and short (Fig 15), nearly reaching free rear tips of pelvics ; clasper depth at base about 2.7 in base width and with a depressed elliptical cross-section; in dorso-ventral view claspers with parallel sides and a broad, bluntly rounded tip; in lateral view, dorsal and ventral surfaces nearly parallel along their lengths but with a short tapering posterior tip. Dorsal clasper groove open, with apopyle dorsolateral on base of clasper and hypopyle dorsal on glans; clasper glans with a long, low flap or cover rhipidion on the mesial edge of groove, a long slit-like pseudosiphon (slot of Leigh-Sharpe, 1922) mesial to cover rhipidion and near rear tip of clasper, and a long pseudopera (slit of Leigh-Sharpe, 1922) on posterolateral tip of clasper.
Dorsal and caudal fins compressed, flexible and close together; first dorsal fin origin above axil between inner edge of pelvic fin and clasper, or about opposite pelvic insertions; apex of first dorsal fin reaches past level of second dorsal fin origin; apex of second dorsal fin reaches well past caudal fin origin; dorsal fins similar in shape, but first dorsal fin slightly larger than second, second dorsal fin height 81- 86 % of first dorsal height, and second dorsal base 86-97 % of first dorsal base; anterior margin of dorsal fins strongly sloping and broadly convex, apices broadly rounded; posterior and inner margins weakly differentiated and convex; first dorsal base about 41-47 % of anterior margin; second dorsal fin base about 41% of anterior margin. First dorsal fin with 6 radials, second dorsal fin with 7; dorsal-fin radials divided into 3 or 4 segments.
Caudal fin fairly high, short, and oval, its lower rear edge forming a continuous broad convex curve to tip of fin, upper margin slightly less convex, tip broadly rounded; vertebral column axis slightly raised; hypaxial lobe narrower than epaxial lobe; fin height 70-78 % of dorsal caudal margin, which is 1.5- 1.6 times in distance from first dorsal origin to upper caudal origin. Caudal fin with 25 dorsal radials (radials 21 & 22 fused at the base) and 31 ventral radials, plus a V-shaped terminal radial.
Antorbital cartilages short, directed anteriorly, with expanded posterior condyle for articulating with sockets on nasal capsules, with narrow shaft and moderately expanded, weakly branched anterior end, separated from anterior extensions of proterygia by ~ 4 cm; rear surface of chondrocranium with two prominent occipital condyles fitting two lateral sockets on anterior surface of synarcual.
Hyomandibula large (Fig 11a & Fig 12a), articulating directly to lateral edge of lower jaw (Meckel's cartilage). On radiographs (Fig 12a; also in Heteronarce, Fig 12b), the synarcual seemed to be divided into anterior and posterior segments above the fourth gill arch, but detailed investigation of radiographs and dissection of the paratype revealed that the ‘joint’ between the two sections was the superimposed anterior edge of the basibranchial copula; a lateral strut on each side that seems to extend from the synarcual to the scapulocoracoid is the fifth ceratobranchial, which extends from the basibranchial to the scapulocoracoid. Vertebral counts are listed in Table 6. Spiral intestinal valve with 17 turns in the paratype (Fig 7).
Live colour: The spectacular and elaborate dorsal colour pattern of live Electrolux addisoni is shown in Figures 1 and 2. The dorsal surface and most of the ventral surface of the disc and pelvic fins, the claspers, the tail and median fins are dark brown covered with dense small pale spots which are white in the preserved types (Figs 3 and 4) but pale yellow in life. The pale spots are larger on middle of dorsal disc, where there are several scattered, short, pale streaks; also light streaks irregularly present in dark ventrolateral surfaces of disc and anteroventral surfaces of pelvic fins near apices. In life the ray is covered with mucus, and there are several curved (some concentric) black stripes on the dorsal disc which disappear when the mucus is rinsed off; the light spots and streaks are often obscured by sediment when the ray is at rest. Ventral surface of disc and pelvic bases abruptly white in center, forming a pearshaped symmetrical blotch from the nasoral turret to the vent and pelvic insertions and including the gill slits and most of the electric organs (Fig 3b, 4b).
ETYMOLOGY. The species is named for Mark Addison, Managing Director of BlueWilderness dive charters of Widenham, KwaZulu-Natal. Mr Addison collected the holotype and instigated the capture of the paratype. He has an extensive knowledge of the marine fish fauna of South Africa and has provided much valued assistance in our fish survey research.
SIZE: The holotype (515 mm TL adult male) weighed 1.8 kg., and the paratype (502 mm TL adult male) weighed 1.9 kg. Electrolux addisoni is apparently one of the largest members of the Narkidae, although females have yet to be examined, and the size range for maturation is unknown for males. Compagno & Last (1999a) noted that the Narkidae includes species that are adult at 9-46 cm TL and possibly reached a greater length, but Electrolux extends this to 52 cm, or possibly greater. Whitley (1940) stated that Typhlonarke aysoni reaches a far greater size than what is known for E. addisoni, with a maximum DW of about. 91 cm. and estimated TL over 122 cm. However, adult male specimens of T. aysoni examined by Whitley (1940), Garrick (1951) and by ourselves were only 21-38 cm. TL, and Garrick (1951: 5) repeatedWhitley’s comments but indicated that “most specimens taken are under 400 mm in total length”. We wonder if Whitley’s maximum DW figure (not his direct observation but based on the comment that “Graham records a maximum width of 36 inches”) might be based on mistaken identity of the much larger Torpedo fairchildi for T. aysoni, although it is extremely difficult to mistake the two. The family Narkidae includes the smallest living batoids (Compagno et al., 1999) and perhaps the smallest or at least the shortest, of the living chondrichthyans (Fig 16). Males of Temera hardwickii examined by us are fully mature at 82-109 mm TL and females at 105-148 mm TL; the species has been reported as reaching 458 mm TL. Adult males of a dwarf species of Narke from the Taiwan Straits are 99-109 mm TL and possibly reach 149 mm (see study material). In comparison to these tiny narkids, Electrolux addisoni is a giant, with the holotype 6.3 times longer and 139 times heavier than the smallest adult male T. hardwickii examined by us (82 mm TL and 13 grams).
Available data for the smallest living sharks suggest that they may be almost twice as long as the smallest narkids. Compagno (1988: 24) discussed the minimum size of sharks and noted that although the diminutive dalatiid shark Squaliolus laticaudus is popularly considered the smallest living shark at a minimum adult length of 150 mm (Fig 16), it has several rivals of similar size. The proscylliid catshark Eridacnis radcliffei matures at 166-242 mm TL, with a 186 mm adult male weighing 14 gm, and a 242 mm pregnant female 37 gm. The etmopterid lantern shark Etmopterus carteri is adult at 186-212 mm, E. perryi is adult at 160-200 mm, E. polli is adult at 229-241 cm and probably smaller (a recently examined adult male is 195 mm long), and E. virens is adult at 181-257 mm. The dalatiid kitefin shark Euprotomicrus bispinatus is mature at 200-266 mm while the two Squaliolus spp. (S. aliae and S. laticaudus) are mature at 15 or 20-25 cm
BIOLOGICAL NOTES. Electrolux addisoni belongs to the sleeper ray family Narkidae, based on the genus Narke and Greek narke, numbness, torpor, that alludes to the sluggish nature of these sedentary rays and the numbing effects of their electric organs. Electrolux addisoni however, is far from torpid while feeding on the substrate (Fig 2a), and vigorously thrusts its mouth into loose sand or gravel while walking actively on its spread pelvic fins. It may lie motionless on the substrate, but when approached can arch its back, curl its disc, and raise its tail to perform a possible threatdisplay directed at the photographer (Fig 2b). The stomach contents of the paratype included the semidigested and fragmentary remains of approximately eight polychaete worms (including a tube-worm) and at least one small shrimp-like crustacean. Stomach contents weighed 5.6 grams. Electrolux as an infauna or meiofauna feeder agrees with the South African narkids Narke capensis, which mostly eats polychaetes (Compagno et al. 1989), and Heteronarce garmani (one specimen examined, Benguela G13531 88N 30-08, 127 mm immature female), which had a stomach filled with mud-balls.
The conspicuous dorsal colour pattern of Electrolux addisoni combined with the ray’s boldness and activeness near divers, and its possible threat display (Fig 2b) may be aposematic and indicates that the ray is well-armed with electric organs and should be avoided. On the shallow, well-lit reefs where E. addisoni has been found, its main potential predators may be large carcharhinoid sharks (requiem sharks, Carcharhinidae, and hammerheads, Sphyrnidae) and lamnoid sharks (ragged-tooth sharks and white sharks). Ebert (1990) found that two species of electric rays successfully defended themselves from much larger sixgill sharks (Hexanchus), which are apex predators with a broad prey spectrum. The small blind narcinid Benthobatis yangi from Taiwan was observed to repel a Hexanchus nakamurai. And two individuals of the larger torpedinid Torpedo cf. nobiliana from South Africa that were examined showed bite patterns of Hexanchus griseus, indicating that the sharks grabbed the rays but were repelled (probably with a shock) before they could inflict a strong and lethal bite. These incidents probably occurred in deep water where the sixgill sharks may have been using non-visual senses to locate their potential prey. Neither of these deepwater electric rays has a prominent colour pattern, and aposematic coloration and threat displays might be of little use to them in a visually limited environment. However, a quick defensive shock apparently can minimize damage by aborting a predator’s attack. For the inshore Electrolux addisoni, aposematic coloration and a threat display might prevent a shark attack if the visual warnings are reinforced by a shock. There are other conspicuously marked inshore narcinids and torpedinids as well as the boldly marked narkid Heteronarce bentuviai, but their behaviour is for the most part poorly known.
DISTRIBUTION AND HABITAT: As presently known, Electrolux addisoni is endemic to the east coast of South Africa in warm-temperate or subtropical waters along approximately 310 km of coastline with a very narrow continental shelf (10-36 km wide to the 200 m isobath) but the few sightings were all inside the 50 m isobath. It could be more wide-ranging elsewhere in warm waters of southern Africa and even off East Africa. Known localities (Fig 17, map) are mostly from dive sites off south-central kwaZulu-Natal (depth and locality data in part from Koornhof, 1995). These include from southwest to northeast (Fig. 17, numbered 1-5): 1, Coffee Bay, Eastern Cape (ca. 31º58’S, 29º9’E; depth ~ 10 m); 2, Manaba Beach, the type locality near Margate (30°51.4’S, 30°23.1’E, depth 6-12 m); 3, Protea Banks, about 8 km off Shelly Beach near Margate (ca. 30º49.8’S, 30º28.8’E, depths ~ 28-35 m); 4, Aliwal Shoal, 4.8 km. off Park Rynie (ca. 30º 19.2’S, 30º48’E, depths ~ 14-30 m.); 5, Tee (or T-) Barge north of Durban and about 3 km off Virginia Beach (an artificial reef habitat at ca. 29º47’S, 31º05’E, depths ~ 20-27 m.).
Wallace’s (1967) survey of electric rays from the east coast of southern Africa did not report this species. To our knowledge, this ray has not been seen south of Coffee Bay or along the south coast to False Bay. Electrolux addisoni was not taken by the South African Marine and Coastal Management’s (MCM) research vessel Algoa during Cruise 014 off Mozambique in 1994 with 28 stations on soft bottom at 37-500 m depth. The Algoa collected torpedinoids in small numbers including Heteronarce garmani, Narcine rierai, and a second species of Narcine similar to the Malagasy N. insolita (Compagno in Smith & Heemstra, 1995, Compagno, 1999b, de Carvalho et al., 2002). The MCM research vessel Africana did not collect either E. addisoni or H. garmani in thousands of inshore and offshore bottom trawl stations at 17-200 m. during two decades of fisheries survey (ongoing) on the east coast of South Africa from Cape Agulhas to Port Alfred. However, Narke capensis were commonly caught by the Africana in this area at 27- 90 m depths (average depth 55 m) and apparently also occur in shallow inshore waters. M. Marks (pers. comm.) caught N. capensis by hand while diving at 4.5 m in False Bay in the Western Cape Province.
Electrolux addisoni occurs on the continental shelf on reefs with sandy or gravelly areas from close inshore to less than 50 m depth and including patches of appropriate habitat on inshore and offshore rocky banks and reefs. We wonder if this conspicuous ray is largely restricted to soft bottom patches on reefs off subtropical South Africa because of its having not been seen or collected elsewhere in southern Africa, including dive sites south of Coffee Bay and off Mozambique.
CONSERVATION STATUS: The conservation status of this ray is uncertain but worrisome, because it is only known from a few records to date on a heavily utilized narrow strip of habitat with extensive and intensive recreational diving and sport and commercial fishing, along with runaway coastal housing development. Its known habitat and geographic distribution suggest that Electrolux addisoni could be at risk from human activities including harassment and disturbance by divers, as well as fisheries, pollution, and habitat degradation. There are no known fisheries that target this species or include it as bycatch, although it might become of some interest in the aquarium fish trade, and it would make a spectacular aquarium exhibit provided one could collect live specimens and keep them successfully in captivity. In terms of its known range and area ‘footprint’ (perhaps not more than a few square kilometers), rarity, and exposure to human activities, this species might rank high on the IUCN Red List criteria for threatened species, possibly Critically Endangered (IUCN, 2006), although there are problems with ranking it with IUCN criteria, because data on trends in abundance are non-existent. The senior author suggests that species of electric rays with limited ranges in the tropical-subtropical southwestern Indian Ocean, particularly species of insular Torpedo and quite possibly narkids and narcinids, are a major (if limited) concern for conservation, as are offshore scyliorhinid catsharks of the genus Holohalaelurus in the area (Human, 2006). Electrolux addisoni would be an appropriate subject for a dive survey project by fish-watchers, professional ichthyologists and conservationists on the numerous dive sites of the northeast coast of the Eastern Cape Province, kwaZulu-Natal and Mozambique to attempt to better understand its distribution and estimate its abundance for the purposes of assessing its conservation status.
TORPEDINOID CLASSIFICATION AND NOMENCLATURE
The classification and nomenclature of torpedinoids used here follows Gill (1862, 1895) and Compagno (1973, 1999a, 2005). For discussion in the text below, detailed data on nomenclature, authors, dates, synonymies and modern equivalents are given for torpedinoid family groups (Fig 3), torpedinoid genera (Fig 4), and species of Narkidae (Table 5). Citations of families, genera and species below are abbreviated by omitting the authors and dates except in formal synonymies. The electric rays (suborder Torpedinoidei or order Torpediniformes) have long been recognized as very distinct from other batoids, with a variety of classifications including a separate order Torpediniformes (eg., Compagno, 1973, 1977) or suborder Torpedinoidea or Torpedinoidei (Bigelow& Schroeder, 1953, Compagno, 2005). Discussion of thehigher classification and interrelationships of torpedinoids to other batoids is not elaborated here but has been considered by many authors. Suffice it to note that in modern studies torpedinoids are always regarded as monophyletic and distinct from other batoid groups and have numerous shared derived characters not found in other batoids.
The classification of electric rays at the familial level had not varied much until the last half of the 20th Century and torpedinoids have usually been placed in a single family without subdivision. Bonaparte (1838) proposed a subfamily, Torpedinini, and Müller& Henle (1841) proposed a single family, Torpedines, for the four valid genera known at the time (Astrape = Narke, Narcine, Torpedo and Temera). Torpedinidae or its numerous synonyms (Fig 3), were utilized by 19th Century and most 20th Century authors for all electric rays. Gill (1862) proposed the division of his family Torpedinoidae (or Narcaciontoidae) for all electric rays into three subfamilies and four subgroups (equivalent to tribes) as follows:
Subfamily Hypninae. Disc pyriform, formed by the union of the true disc with the ventrals, [pelvic fins] which are united beneath the tail; tail very short; head emarginated in front; spiracles far behind eyes; teeth with three points; dorsals [fins] two. Hypnos.
Subfamily Narcaciontinae. Disc and tail nearly equal; head emarginated in front; spiracles far behind eyes; teeth transverse, with one point. Narcacion (= Torpedo), with two subgenera Narcacion and Tetronarce
Subfamily Narcininae. Disc and tail nearly equally long; head entire or convex in front; spiracles close behind eyes; teeth rhombic or hexagonal. [Tribe] Discopygae. Dorsals two, ventrals [pelvic fins] united beneath the tail; teeth rhombic, acute behind; disc orbicular. Discopyge.. [Tribe] Narcinae. Dorsals two, ventrals separated; teeth rhombic, with a median point. Narcine, with three subgenera Narcine, Cyclonarce, and Gonionarce. [Tribe] Astrapae. Dorsal [fin] single. Teeth rhombic, each with a median point; disc sub-circular. Astrape (= Narke). [Tribe]Temerae. Dorsal [fin] obsolete; teeth hexagonal and flat; disc sub-circular. Temera.
Gill (1893) mentioned the division of his family Torpedinidae into three subfamilies, Torpedininae, Narcininae and Hypninae with tribes and generic allocations not specified. Fowler (1934, 1941) proposed the division of the family Torpedinidae into three subfamilies based on presence and number of dorsal fins, as with Gill’s (1862) tribal classification within his Narcininae, but with the union of two-dorsal fin taxa in subfamily Torpedininae for Narcine, Heteronarce, Benthobatis, Hypnos and Torpedo; subfamily Narkinae for the one-finned Narke (including Bengalichthys) and Typhlonarke, and subfamily Temerinae for the finless Temera.
Bigelow & Schroeder (1953) followed Fowler’s classification but raised the rank of his subfamilies to family (Temeridae, Narkidae, and Torpedinidae) and added Discopyge. and Diplobatis to the Torpedinidae. Their classification was followed by a few subsequent authors, including Lindberg (1971) and Rass& Lindberg (1971). Bigelow & Schroeder (1953: 86) cautioned that Fowler’s system based on the number of dorsal fins was artificial, and that it ran “counter to a dichotomous grouping based on the firmness of articulation of the upper and lower jaws and the presence or absence of labial cartilages, characters which are probably of greater importance phylogenetically than the number of dorsal fins.” Bigelow and Schroeder retained Fowler’s arrangement as a matter of convenience, as being appropriate to a general work, and because several of the torpedinoid genera had not been examined for jaw morphology. They expected that a torpedinoid classification based on jaw morphology would eventually replace the dorsal fin scheme.
Fowler (1970) retained a single family Torpedinidae but included a modified arrangement of five subfamilies with a somewhat different composition than his earlier work and apparently incorporating elements of Gill’s (1862) arrangement: Temerinae for the no dorsal fin Temera; Narkinae for the one-dorsal Narke, Typhlonarke and Bengalichthys (= Narke); Discopyginae for the twodorsal Discopyge.; Hypninae for the two-dorsal Hypnos; and Torpedinidae for the one-dorsal Crassinarke (= Narke) and two-dorsal genera Benthobatis, Diplobatis, Heteronarce, Narcine, and Torpedo.
Compagno (1973, 1977, fig. 12) proposed a revised classification of the electric rays based on anatomical comparisons of members of all the torpedinoid genera. The torpedinoids were divided into two well-defined superfamilies, Torpedinoidea and Narcinoidea, that verified and expanded the alternate dichotomous arrangement suggested by Bigelow & Schroeder (1953) as follows:
Superfamily Narcinoidea: Mouth straight, with stout jaws; strong labial cartilages; rod-shaped hyomandibulae; well-developed ceratohyals; branched, antler-like antorbital cartilages; short and broad crania; well-developed frontoparietal fenestrae; rostrum present; occipital condyles not exserted; and disc rounded anteriorly. Families Narcinidae and Narkidae.
Family Narkidae: shallow groove around mouth; narrow, rod-shaped rostrum; nasal capsules anteroventrally directed, contiguous, with a narrow internasal plate; precerebral fossa very small and terminated anteriorly by abrupt constriction of the rostrum; jaws short, stout and weakly protrusile; anterior hypobranchial elements and ceratohyals enlarged; posterior hypobranchials narrow and separated from each other by a wide space; and basibranchial copula small. Genera: Heteronarce, Narke, Temera, and Typhlonarke.
Family Narcinidae. Deep groove entirely surrounding mouth and lips; rostrum broad, trough or shovel shaped; nasal capsules directed ventrolaterally, separated by a wide, flat internasal plate; precerebral fossa very large; jaws long, stout, and strongly protrusile; anterior hypobranchial elements and ceratohyals small; posterior hypobranchials very broad and nearly meeting mid-ventrally; and basibranchial copula moderately large. Genera: Benthobatis, Diplobatis, Discopyge., and Narcine.
Superfamily Torpedinoidea: Mouth arcuate, very extensile, with extremely slender jaws; no labial cartilages; flattened triangular hyomandibulae; no ceratohyals; pinnate antorbital cartilages; crania elongated and narrow; with poorly developed frontoparietal fenestrae; rostrum absent or reduced; occipital condyles exserted; disc truncate and emarginate anteriorly. Families: Hypnidae and Torpedinidae.
Family Hypnidae. Disc pear-shaped, tail rudimentary with two tiny dorsal fins and a small caudal fin; teeth tricuspid; “rostral appendices” articulating with cranium (Haswell, 1885); ethmoid region strongly bent ventrally, with nasal capsules expanded anteroventrally, contiguous, internasal plate narrow and compressed, not separating nasal capsules; preorbital processes absent; otic capsules large, with their outlines expanded abruptly from orbital walls; and one pair of hypobranchials articulating with basibranchial copula. Genus Hypnos.
Family Torpedinidae. Disc subcircular, tail welldeveloped, with two moderate-sized dorsal fins and large caudal fin; monocuspid teeth; “rostral appendices” (Holmgren, 1941) fused to cranium; ethmoid region not bent ventrally, nasal capsules expanded laterally and separate, internasal plate wide and flat; preorbital processes present; otic capsules small, their lateral surface sloping gradually into orbital walls; two pairs of hypobranchials articulating with basibranchial copula. Genus Torpedo.
This four-family torpedinoid classification was utilized by several authors including McEachran& Compagno (1982), Carroll (1988), Compagno (1990, 1999a,b, 2005), Last & Stevens (1994), McEachran et al. (1996), Compagno & Last (in Carpenter & Niem, 1999a, b, c), Compagno et al. (in Carpenter & Niem, 1999), and Carvalho et al. (in Carpenter & Niem, 1999).‘Downranked’ variants of this classification include Nelson (1976, 1984) with a single family Torpedinidae and two subfamilies: Torpedininae and Narcininae with two tribes each. Torpedininae has the tribes
Torpedinini and Hypnini while Narcininae has the tribes Narcinini and Narkini. Nelson (1994) modifies these to two families (Torpedinidae and Narcinidae) with two subfamilies each. Zhu & Meng (1979) used the families Torpedinidae and Narkidae for the two main groups, while Eschmeyer (1990, 1998) used two families Torpedinidae and Narcinidae. Shirai (1996) used one family Torpedinidae and three subfamilies, Torpedininae for Hypnos and Torpedo, Narkinae for the narkids Heteronarce, Narke, Temera, and Typhlonarke, and Narcininae for Benthobatis, Diplobatis, Discopyge., and Narcine.
Our comparison of narkid genera with one another and with other torpedinoids reinforces the distinctiveness of the four families and their grouping into two higher groups (superfamilies) which corresponds to morphological similarities that reflect very different trophic specializations in the two superfamilies. Torpedinoidea feed on large prey that are stunned by the electric organs and swallowed whole through their distensible (snake-like) mouths and flexible jaws. Narcinoidea are bottom feeders that use their more or less protrusible jaws to feed on small prey on or in the substrate. Both groups can use their electric organs defensively against predators, but their utility in feeding is uncertain among the Narcinoidea. A detailed review of torpedinoid systematics and interrelationships of the families and a revision of the Narkidae (particularly Narke including describing new species) are needed, but these tasks are beyond the scope of this paper and more appropriate elsewhere. The present work concentrates on the systematics of Electrolux but has revealed numerous additional characters distinguishing the genera of Narkidae and provides materials for a future cladistic analysis of the genera that would be preliminary and inappropriate here without a revision of the family.
KEY TO TORPEDINOID FAMILIES
Key modified from Compagno et al. (in Carpenter& Niem, 1999)
1a. Mouth broadly arcuate, protrusile and greatly
distensible; no labial folds and cartilages at
corners of mouth......................................................2
FAMILY NARKIDAE FOWLER, 1934. SLEEPER RAYS
Group Astrapae Gill, 1862: 387 (Family Torpedinoidae or Narcaciontoidae, subfamily Narcininae Gill, 1862). Type genus: Astrape Müller& Henle, 1837 (= Narke Kaup, 1826). Proposed as a group that is equivalent to tribe in rank for purposes of nomenclature.
Subfamily Narkinae Fowler, 1934: 240 (Family Torpedinidae). Type genus: Narke Kaup, 1826. Replaces Astrapae Gill, 1862. Family Narkidae Bigelow & Schroeder, 1953: 87; and Narkidae Compagno, 1973: 41.
Group Temerae Gill, 1862: 387 (Family Torpedinoidae or Narcaciontoidae, subfamily Narcininae). Type genus: Temera Gray, 1831. Subfamily Temerinae Fowler, 1934: 240 (Family Torpedinidae), Family Temeridae Bigelow& Schroeder, 1953: 87. Compagno (1973: 41) synonymized Temeridae with Narkidae although Temerae Gill, 1862 has priority.
FAMILY DIAGNOSIS (derived and expanded from Compagno, 1973, 1977, 1999a and Compagno & Last in Carpenter & Niem, 1999a): Electric rays with short preorbital snouts, 5-13% TL; snout broadly rounded anteriorly or nearly truncate (Electrolux and some Heteronarce species). Spiracles contiguous with posterior edges of eyeballs, not situated behind them; margins of spiracles usually smooth and flat or with a low ridge, elevated and occasionally with a few low papillae in Narke capensis, or with several long and prominent papillae that screen the spiracles (Electrolux). Nasal curtain elongated, narrow, posteriorly expanded and thickened, with prominent ampullal pores on its ventral surface. Mouth transverse, small and narrow, not highly distensible; shallow circumoral groove surrounding mouth and lips; labial folds and grooves strong. Tooth row counts low, 8-17 / 7-21 or 15-38 total rows; teeth concealed when mouth is closed; teeth small, rounded-oval, unworn crowns with keels or a single low blunt, broad cusp. Tail fairly large and stout but variably short to moderately elongated. Disc circular, ovate, rounded- angular or pear-shaped, often about as broad as long. Pectoral girdle crescentic; tubular section of lateral faces of scapulocoracoids greatly elongated, longer than medial fenestrated section. Suprascapulae V- or C- shaped, with fused midline above free vertebrae behind synarcual. Superscapulae articulating with scapulae entirely in front of coracoid bar or crossing above bar.Metapterygial axis subequal to propterygial axis or much shorter; propterygial radial count equal to metapterygial radial count or much more numerous. Puboischiadic bar with prominent short to greatly elongated iliac processes. Two dorsal fins (Electrolux, Heteronarce) or one dorsal fin (Narke, Typhlonarke) , or dorsal fin absent (Temera). Caudal fin larger than dorsal fins or fin (when present) and subequal to or somewhat smaller in size than pelvic fins (Typhlonarke with pelvic fins fused to disc); caudal fin without prominent ventral lobe. Craniumshort and fairly broad; rostrum incomplete, medial floor reduced to narrow medial rostral cartilage and paired lateral rostral cartilages below it, lateral walls of rostrum truncated around precerebral cavity and fused to ethmoid region of cranium; medial rostral cartilage rod-shaped with short bifurcated rostral node, less than one-third nasobasal length. Rostral appendices small, separate from rostrum, just lateral to rostral node, and articulating with antorbital cartilages. Precerebral fossa very small and terminated anteriorly by an abrupt constriction of the lateral walls of the rostrum. Ethmoid region anteriorly directed or strongly bent ventrally (Electrolux); nasal capsules expanded anteroventrally or laterally; nasal cartilages (ala nasalis) greatly expanded posterolaterally from the nasal capsules to support the expanded and thickened nasal curtain; internasal plate narrow, compressed, narrowly separating the nasal capsules. Antorbital cartilages more or less branched and antlerlike (narrower distally in Electrolux and in Heteronarce garmani than in other narkids examined); bases of cartilages articulating on posterolateral surfaces of nasal capsules; shafts of cartilages directed more or less anterolaterally; a lateroposteriorly directed spur or process present or absent on shafts of antorbital cartilages. Preorbital processes apparently absent. Cranial roof perforated by frontoparietal fenestra (Narke, Temera, Typhlonarke) or not (Electrolux, Heteronarce); when present long, U-shaped and contiguous with anterior fontanelle or separated from it by an epiphysial bridge. Otic capsules large and broad, length about 33-40% of nasobasal length, width across capsules about 59-68% of nasobasal length, capsules rather inflated and expanded laterally, distally rounded-angular; lateral outlines of otic capsules sloping gradually into orbital walls. Occipital condyles relatively short and low, not strongly exserted from occiput. Jaws stout and transverse, weakly protrusile. Palatoquadrates thick, straight and subtriangular, with strong overlapping processes on their articulation with Meckel’s cartilages; orbital cartilages obsolete to strong on palatoquadrates. Meckel’s cartilages very stout, flat and broad, strongly expanded symphysially and distally, with a weak to strong distal process. A large flat oval mental cartilage just posterior to lower symphysis in most genera (possibly absent in Typhlonarke). Well-developed upper and lower labial cartilages present and close to symphyses, dorsal labial cartilage simple or forked. Hyomandibulae heavy, elongated and sigmoidshaped, with expanded bases and apices; ceratohyals well-developed and large, about size of anterior hypobranchials. Prespiracular cartilages present but postspiracular cartilages absent. Two pairs of hypobranchials, the posterior pair articulating with basibranchial copula; anterior hypobranchials large, as broad or broader than posteriors but not as long; posterior hypobranchials broad to very narrow and separated from each other by a narrow (Electrolux) to wide space (Narke, Temera, with Heteronarce intermediate). Basibranchial copula small and tackshaped (Narke and Temera), larger and more roundedangular in Electrolux and apparently Heteronarce. Dorsal surface usually brownish or reddish-brown, white or brownish below; dorsal surface either plain or with a few large dark spots or blotches, paired white spots, and white side bands on the tail and posterior pelvic bases, usually without a complex colour pattern or ocelli on pectoral fins (Electrolux exceptional with its elaborate colour pattern). Dwarf to moderate-sized batoids, adult males 82-515 mm TL and possibly longer (see size discussion for Electrolux, above).
GENERA OF NARKIDAE AND STATUS OF Heteronarce:
Heteronarce, Narke, Temera, and Typhlonarke were included in the Narkidae (Compagno, 1973), to which we add Electrolux as the second genus of two-dorsal narkid. We initially considered Electrolux addisoni as a possible species of Heteronarce but it soon became apparent that it was very different from any species of Heteronarce and that the four valid species of Heteronarce formed a coherent genus that is separable from Electrolux and other narkids. We present meristic data of Heteronarce and other narkids (Tables 6, 7 & 8) and morphometric data (Table 9) for Heteronarce and and can easily distinguish Electrolux and Heteronarce from each other and from other narkids. Figures 18 and 19 summarize external differences within narkid genera, Figures 6 and 7 show differences in mouth and nostril structures,Figures 5, 9, 10, 11 and 12 differences in head anatomy, Figure 13 pectoral girdle structure and Figure 14 pelvic girdle structure.
There has been considerable confusion in the literature on the status, familial position, and species of Heteronarce. Some authors have doubted its distinction from Narcine and have synonymized the two genera or have mistaken species of Heteronarce for Narcine or vice versa. Part of the problem is that Heteronarce was originally defined on a few nasoral characters that although partially valid were not seen as definitive by some authors, particularly after a few species of Narcine were discovered with elongated, relatively narrow, Heteronarce-like nasal curtains.
The firstvalid species of Heteronarce was described by Lloyd (1907) as Narcine mollis from the Gulf of Aden at 238 m. This was distinguished from the Indian species N. timlei by its enlarged anterior nasal valves (circumnarial folds) and more elongated nasal curtains about as long as wide (about three times wider than long in N. timlei). Lloyd (1909) and Annandale (1909) gave additional information on N. mollis including illustrations of the whole ray, teeth, and oral anatomy. Garman (1913) included N. mollis in Narcine without comments.
The genus Heteronarce was proposed by Regan (1921) for a second new species of two-dorsal electric ray, H. garmani, collected about 15-22 miles off the Umvoti River, kwaZulu-Natal, South Africa, in 120- 130 fms depth, and for Narcine mollis Lloyd, 1907. Heteronarce was distinguished from Narcine by “the minute nostrils, the length of the anterior nasal valves, which are confluent to form a curtain that is not much broader than long and is studded with pores, and the lateral position of the posterior nasal valves.” (Regan, 1921). Regan noted that H. garmani was very similar to H. mollis but had much smaller eyes and spiracles, a longer snout, a smaller mouth and nasal valves, and different coloration (brown above and white below in H. garmani, dark brown above and gray-brown below in H. mollis). Regan did not assign a type species for Heteronarce, but this was subsequently designated as H. garmani by Fowler (1941).
Von Bonde & Swart (1923) described a third species, Heteronarce regani from a 190 mm specimen from kwaZulu-Natal, South Africa (two stations mentioned, depth 211-329 m), but didn’t compare or distinguish it from H. garmani which they also recognized. Their specimen (pl. 22, fig. 2) had a truncated caudal fin tip that is unusual compared to the rounded caudal tips of other Heteronarce species and might be abnormal. The genus Heteronarce was not characterized by these authors.
Fowler (1925a) described a fourth species of Heteronarce as Narcine natalensis, from a 260 mm specimen trawled from off kwaZulu-Natal at 40 fathoms, but didn’t refer to Regan’s or von Bonde& Swart’s accounts and didn’t compare it with either H. garmani or H. regani . Fowler (1925b) subsequently synonymized his N. natalensis with H. garmani , and later (Fowler, 1941) included both N. natalensis and H. regani in synonymy of H. garmani. Fowler’s (1941) synonymy was recognized by Wallace (1967) and is followed here. Fowler (1941) included H. mollis and H. garmani in Heteronarce and separated this genus from Narcine by its more elongated nasal curtain.
Bigelow & Schroeder (1953) included Heteronarce and Narcine in their Family Torpedinidae as separate genera, but noted that Heteronarce (including H. garmani and H. mollis) was so close to Narcine that its generic validity was doubtful, and differed only in its more elongated nasal curtain. However Compagno (1973) noted that Heteronarce “had two dorsals, and had usually been placed in the vicinity of Narcine, but examination of its exterior and skeleton revealed its affinity with Narke.
McKay (1966) described Narcine westraliensis from Western Australia which has an unusually elongated nasal curtain for a narcinid that resembles that of Heteronarce. McKay used this similarity to synonymize Heteronarce with Narcine. However, the chondrocranium and oral structure of N. westraliensis as described by McKay is like that of other Narcine species and of narcinids and unlike that of Heteronarce and other narkids.
Talwar (1981) reviewed Heteronarce and named a fifth species from the southwest coast of India, H. prabhui. Talwar recognized three valid species, including H. garmani from southern Africa (with synonyms H. regani and Narcine natalensis), H. mollis from the Arabian Sea, and H. prabhui from India. Talwar defined Heteronarce as having the disc rounded anteriorly, a shallow groove around the mouth, jaws short and weakly protractile, eyes well developed and almost contiguous with spiracles, nasal curtain only slightly broader than long, and two dorsal fins.
Baranes & Randall (1989), described Narcine bentuviai from 80-200 m. in the Gulf of Aqaba, Red Sea, which proved to be a sixth and unusual species of Heteronarce. Heteronarce bentuviai has a unique bold and black-blotched color pattern and a second dorsal fin noticeably smaller than the first dorsal. H. mollis, H. garmani, and H. prabhui in contrast are uniformly colored and have second dorsal fins about as large as the first. According to Baranes & Randall’s detailed account, the external morphology and anatomy of H. bentuviai agrees with that of other narkids and particularly with other species of Heteronarce but not with Narcine or other narcinids. These authors tentatively placed their species in Narcine because they considered Heteronarce a junior synonym following McKay (1966), but noted that an alternate generic arrangement might remove it from Narcine. De Carvalho (1999) excluded H. bentuviai from Narcine in his revision of the genus.
Lloris & Rucabado (1991) described a seventh species, Heteronarce rierai from off Mozambique, but this proved to be a narrow-bodied Narcine with a narrow nasal curtain as in N. westraliensis but like that species has mouth and anatomical characteristics typical of narcinids (Compagno, in Smith & Heemstra, 1995, de Carvalho, 1999). There are several other narrow-bodied species of Narcine in Australian waters (MacKay, 1966, Last & Stevens, 1994, de Carvalho, 1999).
The superficial external similarity of Heteronarce to Narcine is contradicted by its anatomical and external differences (particularly in the oral and chondrocranial morphology) which are similar to those of other narkids rather than Narcine or other narcinids. Based on our examination of Heteronarce specimens, as well as literature data, we confirm that Heteronarce is a valid and well-defined genus including the four species H. bentuviai, H. garmani, H. mollis, and H. prabhui, with the latter species morphologically very similar to H. mollis. Heteronarce is separable fromnarcinids by characters in the key to families and definition of the Narkidae above, and separable from other narkids in the key to narkid genera and in comparison with Electrolux.
KEY TO NARKID GENERA
1a. No dorsal fins................................................Temera
(Indo-West Pacific from Andaman Sea near
southern Thai-Burma border through Straits of
Malacca and Malay Peninsula to Singapore,
Thailand and Viet-Nam, doubtful from
INSTITUTIONAL ABBREVIATIONS: Institutional abbreviations for specimens of Narkidaemostly follow Compagno (1988): BMNH - Natural History Museum, London, UK, formerly British Museum (Natural History). CAS - California Academy of Sciences, San Francisco, California, USA. GVF - George Vanderbilt Foundation fish collection, Stanford University, Stanford, California, USA, housed at the California Academy of Sciences. ISH - Institut für Seefischerei, Hamburg, Germany. KUMF - Kasetsart University. Faculty of Fisheries, Museum, Bangkok, Thailand. LJVC - XXXX and LJVC - YYMMDD (Year, Month, Day), L.J.V. Compagno accession number and fieldaccession number. PCH - Phillip C. Heemstra field numbers. NMS - National Museum of Singapore (formerly Raffles Museum) zoology collection, housed in the Department of Zoology, National University of Singapore. SAIAB - South African Institute of Aquatic Biodiversity, formerly RUSI, for the J.L.B. Smith Institute of Ichthyology, Grahamstown, South Africa. SAM- Iziko - South AfricanMuseum, Natural History Division, department of Marine Biology, Cape Town, South Africa. SIO - Scripps Institution of Oceanography, La Jolla, California, USA. SU - Stanford University fish collection, Stanford, California, USA, housed at the California Academy of Sciences. USBCF - United States Bureau of Commercial Fisheries, Department of the Interior field number. Now US National Marine Fisheries Service, Department of Commerce. ZRC - Zoological Reference Collection, Department of Zoology, National University of Singapore.
COMPARATIVE MATERIAL - FAMILY NARKIDAE
"Crassinarke dormitor" (? = Narke japonica), SIO 4-257-6B, 278 mm TL adult male, Yellow Sea.
Heteronarce garmani: BMNH 19220.127.116.11, holotype, adult male, 169 mm TL, 77 mm DW, 1921, Umvoti River, kwaZulu- Natal, South Africa, 220-238 m. SAM34813, two adult males, 256-289 mm TL and 124-135 mm DW, RV Algoa, C00813 014 011-3115, 19940612, Western Indian Ocean, Mozambique, 23° 28.0’ S, 35°43.00’ E, 185 m. SAM uncataloged, two females, 125-132 mm TL and 65-72 mm DW, adolescent male, 145 mm TL and 64 mm DW, RV Benguela G13531 88N 30-08, 19880822, kwaZulu-Natal, South Africa, 29°44.0’ S, 31°23.00’ E, 154 m.
Heteronarce mollis: CAS 58352, 206 mm TL, 92 mm DW adult male, RV Anton Bruun, AB 9-444, 19641216, N. Indian Ocean, Somalia, 9° 36.00’N, 51° 1.00’E, 78-82 m. CAS 58351, 6 females, 217, 226, 255, 218, 211 and 212 mm TL, 115, 120, 122, 111, 108 and 100 mm DW, 2 adult males, 220 and 199 mm TL, 118 and 100 mm DW; immature male, 165 mm TL and 90 mm DW, RV Anton Bruun, AB 9-464, 19641218, N.
Indian Ocean, Somalia, 11° 37.00’N, 51° 27.00’E, depth? ISH 254/75, adult male, 199 mm TL, 100 mm DW, Dr. F. Nansen, FAO, 19750303, North coast, N. Indian Ocean off Somalia, 11°41.00’ N, 51°36.00’E, 82 m.
Narke capensis: (all from South Africa): Africana A04752 048 030-1039, immature males, 87, 94, 98 mm TL, 52, 53, 57 mm DW, adult males, 206, 250 mm TL, 142, 165 mm DW, immature female, 89 mm TL, 49 mm DW, adult (?) females, 205, 215, 223, 233, 255 mm TL, 133, 133, 137(?), 153, 164 mm DW, adult females, 193, 208, 220, 220, 224, 232, 234, 245 mm TL, 120, 139, 136, 145, 146, 156, 146, 173 mm DW, 19860920, southeastern Cape coast, , 34°16.0’ S, 22°1.0’E, depth 42 m. Africana A04770 048 043-1093, adult males, 176, 237, 245 mm TL, 119, 153, 154 mm DW, immature female (?), 155 mm TL and 101 mm DW, females, 145, 165, 171, 192, 218 mm TL, 96, 108, 105, 128, 140 mm DW, 19860923, southeastern Cape coast, , 33°48.0’S, 26° 7.0’ E, depth 56 m. Africana A06215 056 023-1042, adult males, 243 and 253 mm TL, 154 and 153 mm DW, adult females, 196 and 213 mm TL, 115 and 120 mm DW, 19870917, southeastern Cape coast, , 34°7.0’S, 22° 15.0’E, depth 40 m. Africana A07115 063 011-2123, adult male 243 mm TL and 172 mm DW, 19880513, southeast Cape coast, 34°30.0’S, 21°14.0’E, depth 59 m. Africana A07116 063 012 2132, male (adult?) 253 mm TL, 155 mm DW, 19880513, East coast cruise, Cape coast, 34°31.0’S, 21°17.0’E, depth 58 m. Africana A07128 063 020-1039, immature female, 118 mm TL, 75 mm DW, adult females, 225, 229, 246, 254, 263 mm TL, 136, 143, 156, 162,169 mm DW, adolescent male, 257 mm TL, 168 mm DW, adult males, 243, 253 mm TL, 173 mm DW(253 mm TL), 19880515, southeastern Cape coast, 34°16.0’S, 22°1.0’E, depth 35 m. Africana A07152 063 038-1093, adult males, 175, 178, 215, 255 mm TL, 117, 123, 134, 170 mm DW, adult females, 155, 175 mm TL., 95, 112 mm DW, 19880519, southeastern Cape coast, 33°45.0’S, 26°5.0’ E, depth 32 m. Africana A13339 102 014-2332, immature male 73 mm TL, 50 mm DW, 1992040, southeastern Cape coast, 33°53.0’S, 26°46.0’E, depth 90 m. Africana A16338 122 043-1042, immature male, 105 mm TL, 68 mm DW, adult female, 176 mm TL, 109 mm DW, 19940618, eastern Cape coast, 34°9.0’S, 22°13.0’E, depth 39 m. SAM 34347, adult male, 174 mm TL, 118 mm DW, Africana A18168 135 077-1090, 19960429, southeastern Cape coast, , 33°45.0’S, 26°1.0’E, depth 27 m. depth. LJVC 961014, SAM uncataloged, adult male, 265 mm TL, 180 mm DW, M. Marks site 1, 19961013, Buffels Bay, False Bay, Western Cape, , 34°19.06’S, 18° 27.75’E, depth 4.5 m. RUSI 11932, adult male, 195 mm TL, 115 mm DW , TBD- 3, off Swartkops, Eastern Cape, . SAM22796, female, 188mm TL, 120 mm DW, 19590919, Algoa Bay, Eastern Cape, . SAM 22799, female 170 mm TL, 101 mm DW, 19590916, Sandy Point, Mazeppa Bay, Eastern Cape, 32°27.00’S, 28°39.00’E. SAM 30992, adult male, 239 mm TL, 156 mm DW, 19781103, Muizenberg, False Bay, Western Cape.
Narke dipterygia: BMNH 1909.7.12.13, female, 121 mm TL, 57 mm DW, syntype of Bengalichthys impennis Annandale, 1909, Balasore Bay, Orissa coast, India. CAS uncataloged, female ca 120 mm TL, 50 mm DW, Indo-West Pacific. CAS 66840, female, 146 mm TL, 78 mm DW, collected by J. Mee, 19890222, Sudah, Oman, 6 m depth. LJVC 0508, five females, 170, 150, 150, 162 and 155 mm TL, immature male, 165 mm TL, F. Steiner, 19751006, Taiwan straits?, Taiwan. LJVC 0514, 157 mm TL adult (?) female, F. Steiner, 19751006(?), Taiwan straits, Taiwan? LJVC 0515, adult (?) females, 146 and 151 mm TL, F. Steiner, 19751006, Taiwan straits, Taiwan(?). J. Randall uncataloged, female, 131 mm TL, India. NMS 3119, adult males, 150 and 131 mm TL, 84 and 70 mm DW, A. K. Tham, 1964, Fisheries Biology Unit, SPR 425, Singapore. SU 32406, adult male, ca. 135 mm TL, 65 mm DW, India. SU 41717, adult male ca 150 mm TL and female ca 135 mm, India. USBCF F.H. Berry no number, two adult males, 170 and 180 mm TL, five females, 178, 153, 166, 130, 153 mm TL, Porto Novo, Madras, India. USBCF F.H. Berry, SOSC-381, female ca 160 mm TL, Porto Novo, Madras, India, 15-22 m. depth,
Narke cf. dipterygia, KUMF 2464, female, 120 mm TL, 75 mm DW, 19740105, Samut Songkram, Thailand,. KUMF 0807, female, 123 mm TL, 69 mm DW, 1968, collected by P. Wongrat, Prachuat Khiri Khan, Gulf of Thailand, KUMF 0834, females 109, 114 and 112 mm TL, 64, 66, 66 mm DW, 1972021-10, collected by P. Wongrat, offshore near Sataheys, Gulf of Thailand.
Narke japonica: CAS Acc. 1972:1:5, female, 233 mm TL, 19711200, East. China Sea, between Japan and Korea. GVF Naga 60-61 (GVF-2077), adult male ca 225 mm, 19600227, South China Sea, 15°40.00’N, 109°25.50’E. PCH Jan. 1988, female 168 mm TL, 93 mm DW, 1988, from Tachi, South China Sea, Taiwan. SU 3363, adult male, ca. 365 mm TL, Japan. SU 61723, female ca 215 mm TL, Japan. SU 7267, adolescent male, ca 195 mm TL, Japan.
Narke spp. CAS Acc 1972-XII: 18, immature male, 67 mm TL, adolescent males, 94 and 109 mm TL, adult males, 99 and 103 mm TL, females, 58 and 93 mm TL, southwest of Kao Ksiung, Taiwan. Anton Bruun, AB 4B-263, immature male, 100 mm TL, adult males, 143 and 147 mm TL, females, 117, 121, 127, 127, 132, and 139 mm TL, Arabian Sea, 22°54’N, 68°06’E. GVF-2430, female ca 150 mm TL, Gulf of Thailand, Thailand. GVF-2449, adult males, 153 and 154 mm TL, female, ca. 125 mm TL, Gulf of Thailand, Thailand. GVF- 2663, female ca 150 mm TL, Gulf of Thailand, Thailand. CAS Anton Bruun AB 4B-223A, females, 130, 150 and 165 mm, Arabian Sea, 22°54’N, 68°06’E, depth 16 m.
Temera hardwickii : BMNH 1918.104.22.168-10, female, 139 mm TL, 73 mm DW, and adult male, 108 mm TL, 55 mm DW, from Penang, Malaysia, syntypes of Temera hardwickii Gray, 1831. CAS 58369, adolescent males, 74 and 84 mm TL, 44 and 49 mm DW, female, 108 mm TL, 59 mm DW, Anton Bruun Sta. 0248, 9°54’N, 97°42’E, Andaman Sea, SSW of Kawthaung, Isthmus of Kraa, Burma, 0-200 m. KUMF 0014, female, 136 mm TL, 86 mm DW, 19650823, Phuket (Puket), Thailand, depth 91-105 m. KUMF 2916, females, 78 and 142 mm TL, 36 and 85 mm DW, adult or late adolescent male, 88 mm TL, 44 mm DW Songkhla Research Vessel, S. Mongkolprasit, 198412, Thailand. NMS 2090, adult female, 148 mm TL, 76 mm DW, M. Tweedie, identified by A.W.C.T. Herre, 1940, fish market, Singapore. NMS 2110, adult (?) female, 140mmTL, 81mmDW, R.L. Chermin, 1954, det. E.R. Alfred, 680615, Changi, Singapore. SU 35728, adolescent male, 104 mm TL, 64 mm DW, A.W.C.T. Herre, 1936-1937, Telok Kurau, Perak, Malaysia, SU 35736, immature female, 74 mmTL, 38 mm DW, adolescent female, 105 mm TL, 62 mm DW, adult female, 119 mm TL, 62 mm DW (cranium dissected), A.W.C.T. Herre, Singapore. ZRC no number, adult male, 82 mm TL, 48 mm DW, no locality data or other information, presumably Singapore, ZRC no number, female (possibly adult), 121 mm TL, 72 mm DW, Ahmad Draman, 19630811, Ponggol, Singapore. ZRC 10588, adult male, 109 mm TL, 66 mm DW adult male, Ahmad Draman, 19640801, Ponggol, Singapore. ZRC 38918, adult female, 122mmTL, 78 mm DW, K. Lim, P.K.L. Ng, et al., June 1995, Pulau Bintan, north coast, Tanjung Tondang, Sumatra, Indonesia.
Typhlonarke aysoni: LJVC 0424, adult male, 205 mm TL, 110 mm DW, Kaikoura coast, South Island, New Zealand, 110 m. SIO 61-149-6A, immature female, 92 mm TL, 48 mm DW, 19610129, NW of Mernoo Bank, South Island, New Zealand, 43°39.0’S, 175°15.0’E, 0-119 m.
We thank Mark Addison and his father Brent Addison for their efforts in collecting and donating the two specimens of Electrolux addisoni to the South African Institute for Aquatic Biodiversity. We are grateful for the images of the live fish supplied by Stefania and Peter Lamberti, Dennis King, Avril and Len Fish, and Peter Chrystal through Rudy van der Elst. We thank Elaine Heemstra for her assistance with the drawings. Thanks also to Mark Marks, Mike Bougaardt and Liz Hoenson of Iziko-South African Museum. The first author thanks the curators and collection managers at the following institutions for allowing him to examine narkid specimens in their collections: Natural History Museum, London, UK; California Academy of Sciences, San Francisco, California, USA; Institut für Seefischerei, Hamburg, Germany; Kasetsart University. Faculty of Fisheries, Museum, Bangkok, Thailand; National Museum of Singapore (formerly Raffles Museum) zoology collection and Zoological Reference Collection in the Department of Zoology, National University of Singapore; Scripps Institution of Oceanography, La Jolla, California, USA.
© 2007 The South African Institute for Aquatic Biodiversity, Grahamstown, South Africa
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