Metazoan parasites of some commercially important fish along the Kenyan coast

Abstract

The parasitic fauna of some commercial fish species along the Kenyan coast was investigated at four localities between August 2001 and March 2002. The study was carried out to establish the extent of parasitisation of different fish species and quantify the relationship between the parasites and their fish hosts. Fish samples were collected once a month from four landing beaches. Sixteen fish species were examined out of which only eight were infested with ecto-and endo parasites. The infested fish species included: the rabbitfish (Siganus sutor), the mackerels (Selar crumenophthalmus, Scomberomorus commerson and Rastrelliger kanarguta), parrot fish (Leptoscarus vagiensis), sardine (Sardinella gibbosa), tuna (Thunnus sp.) and needle fish (Hemiramphus far). Of the eight species, Si. sutor was most infested with parasites while Sardinella and Leptoscarus were primarily infested wit h ectoparasites (isopods). Intensity of infestation increased with age (size), especially in Si. sutor, where very young fish had a low infestation rate, while adults were heavily infested (P < 0.01). No significant differences were observed in the intensity of infestation between sexes in Si. sutor (P > 0.05).