Gill morphologies of two subspecies of Gymnocypris przewalskii
( Gymnocypris przewalskii przewalskii
and Gymnocypris przewalskii ganzihonensis
) in different habitats were analyzed under scanning electron microscope. Results indicated that G. p. przewalskii
had numerous long and dense-lined gill rakers while G. p. ganzihonensis
had few short and scatter-lined gill rakers. There were no significant differences in distance between gill filaments (DBF) and distance gill lamella (DBL) between the two subspecies, but gill filaments of G. p. przewalskii
were longer than in G. p. ganzihonensis.
The electron microscopic study indicated that the pavement epithelium cells of G. p. przewalskii
were well defined as irregular ovals, but were hexagonal in G. p. ganzihonensis
. Moreover, G. p. przewalskii
had more chloride cells than G. p. ganzihonensis
, and mucous cells were only found on the surface of gill filaments of G. p. przewalskii
. The morphological differences between the two subspecies of G. przewalskii
are adaptations to their corresponding diets and habitats.