Infection of the epaulette shark, Hemiscyllium ocellatum (Bonnaterre), by the nematode parasite Proleptus australis Bayliss (Spirurida : Physalopteridae)

Seventy-two epaulette sharks, Hemiscyllium ocellatum (Bonnaterre), were inf ected with the nematode parasite Proleptus australis Bayliss, 1933. The par asite population was overdispersed. Infection intensity ranged from 3 to 10 02 worms per fish stomach, and there was a positive correlation between sha rk length and number of parasites present. The majority of worms were attac hed to the stomach wall, and scanning electron microscopy and histological examination showed that worms penetrated the stomach lining. Worms were obs erved within the lamina propria of the stomach and occasionally penetrated the muscularis mucosa. Little to no inflammatory or cellular immune reactio n to the presence of the parasites was observed, except in one case where a worm was being degraded by a host tissue response. There was a large amoun t of connective tissue proliferation as a result of nematode attachment,, b ut no obvious effects on the overall health of the sharks were seen. Three sharks were also found to be infected by the cestode Callitetrarhynchus sp.