Parasitic Isopod Cymothoa eremita (Brunnich 1783) (Isopoda: Cymothoidae) Affects the Growth of Black Pomfret Parastromateus niger (Bloch 1795) in the Southeast Coast of India

The black pomfret Parastromateus niger is often favored host for infestation by the cymothoid, buccal attaching ectoparasite Cymothoa eremita. This investigation aimed to evaluate the health status of black pomfret by means of relative condition factor under the existing parasitic cymothoids. Prevalence of C. eremita on black pomfret fish was high (42%) but large (>300mm) and small fish (< 250) showed significantly lesser prevalence than intermediate-sized host fish. The harmful effects of parasite infection on their hosts include basihyal damage, a loss in buccal cavity volume as a result of female cymothoid infestation, and a severe impact on host growth. The diet composition examination was a small indication to suggest a change in either feeding habits or diet of fish where parasitized and non-parasitized fish occupied the similar tropic niche. Due to an infestation of C. eremita in P. niger, the relative condition factor in infested was found to be lower than that of the uninfested fish. C. eremita infestation can impair growth and decrease feeding efficiency in hosts, subsequently affecting health condition and survival.