Population Dynamics of Metazoan Parasites of Rhizoprionodon acutus from the Nellore Coast off Bay of Bengal

ABSTRACT

Rhizoprionodon acutus (Rüppell) 1837, commonly known as ‘Milk shark’ is the frequently available elasmobranch from the Nellore (14.43°N 79.97°E.) coast off Bay of Bengal. A total of 152 R. acutus were collected from this coast during January, 2014- December, 2015, of which 89 hosts were infected with one or more parasites. A total of eleven species were collected, comprising of 6 cestodes, 2 nematodes, 1 Monogenean, 1 copepod and 1 isopod. Various ecological parameters such as prevalence, mean intensity, mean abundance and index of infection were calculated to determine the monthly population dynamics and the seasonal dynamics of the parasites in R. acutus. The study was carried out for both overall and groupwise parasitization. Endoparasitic infection predominated the ectoparasitic infection in the host. The study reveals the role of the temperature and season in the recruitment of parasite fauna in the hosts. The present study would be a great contribution to the knowledge of the metazoan parasite fauna of elasmobranch fishes to the future helminthologists from this Nellore Coast, Bay of Bengal.