Grillotia perelica(Cestoda: Trypanorhyncha) plerocercoids in mullet (Pisces: Mugilidae) from estuaries in Transkei, southern Africa

Grillotia perelica plerocercoids Were found in the musculature of eight of 10 mullet species collected in three Transkei estuaries between March 1987 and April 1990. Prevalence of infection was high (15–50%) in Mugil cephalus, Liza richardsonii, L. tricuspidens, Valamugil buchanani and V. robustus, but low (<5%) in Myxus capensis, L. dumerilii and V. cunnesius. No infected L. alata or L. macrolepis were found. Intensity of infection was high (up to 19 worms) in M. cephalus but low (<4 worms) in the other mullet species. Infection was restricted to adult fish and prevalence increased with size of fish. The parasites recruited to fish annually during spring. Infection varied between estuaries. Mullet in the Kei Estuary had a lower prevalence of Grillotia than conspecifics in the Mbashe and Mntafufu estuaries, where infection patterns were similar. These differences are partly accounted for by regional variations in the abundance of the final hosts, the sharks Carcharhinus leucas and C. plumbeus. C. leucas is a new host for G. perelica. Inter- and intraspecific variations in infection of the mullet species are discussed in relation to their diet and spawning seasons and areas.