Biodiversity Of Helminth Parasites Of Fishes In The Arabian Gulf, With Special Reference To Digenetic Trematodes And Cestodes

Abstract

Biodiversity of the fish fauna in the Arabian Gulf is remarkable with more than 450 species known to date in this offshoot from the Indian Ocean. The present status of our knowledge on helminth parasites of fishes in the Arabian Gulf is reviewed in the light of the results of a recent investigation on fishes caught from Qatari waters. Biodiversity of digenetic trematodes and cestodes at the generic level in both bony and cartilaginous fishes of the Arabian Gulf is more remarkable. So far 36 genera of digenetic trematodes have been recorded from 61 species of bony fishes. Infections with one genus of digenetic trematodes are known from 26 species of fish. Infections with two genera of these parasites are reported from 16 species offish hosts while three genera of digeneans occur in 11 species of fish. Four - ten genera of digenetic trematodes are reported from another 8 species of fish in the Gulf. On the other hand, 14 species of cartilaginous fishes have infections with 9 genera of adult cestodes, distributed throughout the cestode orders Diphyllidea, Tetraphyllidea and Lecanicephallidea, in addition to some unidentified trypanorhynchans. Variations in the prevalence and the generic diversity of digenetic trematodes and cestodes in fishes of the Arabian Gulf are presented together with a discussion on certain aspects of the relationships between these helminths with their respective fish hosts.