External lesions and flesh parasites in commercial fishes of Nigerian inshore waters

Abstract

Commercial fish species from the east Nigerian Coast were cxamined for extcrnal lesions and flcsh parasitic infections that may affect thcir consumahility. Altogether, 2 886 specimens from 43 species representing 34 genera werc sampled. The occurrence of lymphocystis disease in the pleuronectiform Cynoglossus senegalensis is here rcported for thc first time from an African marinc teleost. Other external lesions of fishcs cncountered were fin rot, granulomas, pseudotumours and ulcers with total prevalences not exceeding 1 %. The following commercial fish spccics were infectcd by muscle parasites at thc given prevalcnces: Cynoglossus brouni (mctaccrcariae, 18%, Capilluriu b pino osa cggs, 27%; Echinocephalus sinensis L3 larvae, 9%; Philomerru beninensis, 27%); C. senegulensis (Kudou sp., 10%; metacercariac, 87%); Pseudotolirhus bruchygnuthus (Hysterothylucium sp. larvae, 2%); P. srnegulensis (Poeciluncistrum cf caryophyllum plerocercoid, 1 %; Philometru beninensis, 1 %); P. typus (Kudou sp., 3%); Synapturu cadenati (Echinocephalus sinensis, 12%); Stromuteus jÏutola (trypanorhynch plcrocercoid, 44%); Epinephelus aeneus (didymozoid trematode, 44%; Hy~terothyluciunz sp. larvae, 6%). Cupillrrria and Echinocephalus, representing helminths with zoonotic potential, present low risks to public health due to their low prcvalences and the local methods of preparing fish for consumption. Apart from C. spinosa eggs in soles and trypanorhynch plerocercoids in S. fiutola, none of the other flcsh parasites are likely to affect the market value of thcir hosts at the rccorded levels of occurrence. Carcharhinid sharks influence the occurrence in the locality of most flesh-parasitic helminths for which they serve as definitive hosts. The absence of the third stage larvae of zoonotic Anisakidac common in marine fishes from many other parts of the world is related to the unavailability of suitable hosts. Compared to the results from most temperate locations whcre similar studics have been earried out, the present study shows remarkably low prevalences and diversity for external lesions and flesh parasites in West African marine fishes.

Trypanorhynchid cestodes of commercial inshore fishes of the West African coast

“…Two other otobothriid species have been reported in a previous communication from the same area (Obiekezie et al, 1992). Two plerocercoids of Pc~ecilancistrurn caryuphyllum were isolated from the musculature of 1 out of 79 Pseudotolithus senegalensis examined.…”

“…On the other hand, reports on fish cestodes of the South East Atlantic are scarce. Particularly from the gulf of Guinea the only published records are those of Bane (1969), Baudin-Laurencin (1971), Bussieras and Aldrin (1965), Reimer (1984) and Obiekezie et al (1992), al1 of which are essentially isolated observations on single or a limited number of species.…”

Trypanorhynch Cestodes of Commercial Fishes from Northeast Brazilian Coastal Waters

“…Only two tetraphyllid species were found in the fish examined. Related to the unavailability of suitable final hosts, no pseudophyllids including the zoonotic genera Diphyllobothrium and Diplogonoporus were found (Obiekezie et al 1992, Palm et al 1994.…”

“…Though flesh infestations have not been reported for O. cysticum during a recent study (Obiekezie et al 1992, Palm et al 1994, O. crenacolle, which was seen as a junior synomym for O. cysticum by Palm (1995), causes marketing problems for the butter fish Prionotus triacanthus at the Northeast American coast (Linton 1908 (Bilquees & Shaukat 1976, Hildreth & Lumsden 1985, Reimer 1989. Thus a flesh invading potential of the species should not be excluded.…”

Otobothrium cysticum (Cestoda: Trypanorhyncha) from the muscle of butterfishes (Stromateidae)

“…Reimer (1984) and Palm et al (1994), however, encountered another stromateid infection in West Africa involving an unidenti®ed species of Otobothrium in the muscle (see Fig. 2K of Obiekezie et al 1992). As indicated above, individuals of O. cysticum are also reported to be common on the viscera, including the mesentery, and in the submucosa of the stomach and intestine of numerous teleost and elasmobranch species.…”