Ecology of metazoan parasite community of marine threadfin fish, Polydactylus sextarius (Bloch and Schneider, 1801) from Visakhapatnam Coast, Bay of Bengal.

摘要

In this study, the structure and diversity of metazoan parasite community and their interactions with 696 Polydactylus sextarius have been studied for two consecutive years 2005-2006 and 2006-2007 from Visakhapatnam (17.67 degrees 'N and 83.32 degrees 'E), in the coastal zone of Bay of Bengal Andhra Pradesh. Of the 676 host species examined, 563 (83%) hosts were parasitized by at least one or more metazoan parasite species. A total of 5911 specimens were obtained representing 24 species comprising 2 monogenetic trematodes, 11 digenetic trematodes, 2 cestode larvae, 1 nematode, 4 Acanthocephalans, 3 copepods and 1 isopod. Endoparasites preponderate the majority of the components of the infracommunities analysed and represented 92.6% of the total parasites obtained. Larval cestodes (3515) and digeneans (1165) were the most prevalent in the parasite community of the host. Larval cestode, Scolex pleuronectis is the only secondary species while the remaining are satellite species being less in number. Impact of abiotic factors like temperature, water currents and biotic factors like feeding habit, diet, immunity, lifespan of host on parasitization; the relationship between host size and prevalence of infection were thoroughly investigated but the host sex was not taken into consideration due to protandrous nature of the host.