TRYPANORHYNCHID CESTODES OF COMMERCIAL INSHORE FISHES OF THE WEST-AFRICAN COAST

A wide spectrum of fish hosts in the Gulf of Guinea was examined for i nfestation with trypanorhynchid cestodes. A total of 1341 specimens be longing to 45 species were examined. The following 9 trypanorhynchid s pecies were identified: Callitetrarhynchus gracilis, Grillotia perelic a, Nybelinia sp., Otobothrium cysticum, O. dipsacum, Otobothrium sp., Poecilancistrum caryophyllum, Ptero-bothrium sp. and one identified sp ecies. The pattern of occurrence of Callitetrarhynchus gracilis has be en used to draw conclusions on a possible 4-host life cycle of the spe cies, involving two obligatory teleost host fish species, small clupei ds and large predatory fish. The most abundant parasite was O. cysticu m which was found in 8 host fishes. In general most other species occu rred in one host fish species only. The study confirms the predominanc e of otobothriid cestodes in the parasite fauna of tropical and subtro pical teleost fish species. Since only Pseudotolithus senegalensis and Stromateus fiatola harboured flesh infestations, trypanorhynchids do not pose serious dangers to the marketability of most commercially imp ortant fish species in the area. The method of scanning electron micro scopy was used to clarify the details of hooklet arrangement on the te ntacular armature of some species for the first time.