Several species of snails, including
Pomacea haustrum
,
Marisa cornuarietis
and
Helisoma duryi
, have been identified as probable competitors and/or predators of planorbid intermediate hosts of
Schistosoma
. During the last few years, studies carried out in the Caribbean region have shown reductions and even disappearances of populations of
Biomphalaria glabrata
and B.
straminea
in breeding places where the snail
Melanoides tuberculata
was introduced. Observations made over a period of 10 years in two lakes close to Belo Horizonte, MG, showed that there were marked reductions in autochthonous populations of
B. glabrata and
B. straminea after the arrival of M.
tuberculata
, both
Biomphalaria
species disappearing completely after eight years.
