The composition, richness and similarity of helminth communities in a
tropical freshwater fish were determined in samples
of Cichlasoma urophthalmus collected from 7 localities of broadly
similar age and character situated along the northern
coast of the Yucatan peninsula, Mexico. The component communities exhibited a
unique combination of characteristics
for a freshwater fish. They were dominated by digeneans, with all other
helminth groups being numerically inferior. A
common suite of species could be recognized, but many of its members were
generalists and not cichlid specialists. Species
richness and number of individuals per host were high, but diversity was
low, reflecting high dominance by one species.
Intra- and inter-locality similarity levels were low, and local variation high.
In respect of species richness and digenean
dominance, the communities resembled those in Australian tropical anguillids,
but in respect of low diversity, similarity
and high dominance they are more similar to helminth communities of
northern temperate fish.