Prevalence, intensity and gonadosomatic index of a nematode (Philometra sp.) infested in ovaries of Otolithes ruber from Southeast coast of India

ObjectiveTo carry out the prevalence, intensity, gonadosomatic index (GSI) of a nematode (Philometra sp.) infested ovaries of Otolithes ruber (O. ruber).MethodsThe specimen was encountered from January to December (seasons from post monsoon to monsoon), 2012. The Philometra nematode species are collected from a female specimen in the ovary of O. rubber and the worms ware described. The ovaries were dissected and examined the prevalence intensity and GSI of nematode infection for each fish.ResultsThe present study showed the result of the nematode body length of gravid female (294.70±2.99) mm and (147.50±4.11) mm in maximum width. The percent of overall prevalence is 28.66%±10.17% and intensity of 1–3 nematodes per fish. That may prevent proper development of oocytes and probably affect O. ruber fecundity. Because the average GSI was 2.04 per fish, the number of ova per gram body weight of fish was found as (158.00±3.90) ova/g and the number of ova per cm of length of body was found to be (55 795.0±149.4) ova/cm.ConclusionsPhilometrids parasitizing in the gonads of their hosts may cause serious damage to these ovaries by lapping blood, which leads to the atrophy of developing ova in the ovary, the fibrosis of ovarian tissue, and results in granulocytes and bleeds, thus negatively affecting the reproduction of O. ruber.