Occurrence of infestation with the isopod, Alitropus typus M. Edwards (Crustacea: Flabellifera: Aegidae) on commercially important freshwater fishes of Kerala, India

AbstractRapidly rising temperatures and increasing organic load in the inland and coastal waters has led to a significant increase in parasite population. The isopodAlitropus typus infestation on fish in these waters have become more frequent, causing mortalities in both wild and cultured fishes. The present study was aimed to investigate the infestation on different fish hosts, mean intensity, prevalence, environmental influences on the parasite abundance and the histopathological changes it causes in the host. A total of 219 isopod specimens were collected from 149 infested fishes in two districts of Kerala, India. Among the different fish hosts,Channa striata was found to be the most susceptible, followed byCatla catla, Cyprinus carpio, andWallago attu, with 81%, 10%, 7%, and 2% occurrence, respectively. The prevalence and mean intensity of infestation were found to be 69.8%, 44.4%, 68.2%, 62.5% and 1.33, 4.25, 1.26, 1.80 inC. striata, W. attu, C. catla, and C. carpio, respectively. The parasite abundance was directly influenced by temperature. The histopathology of affected gill tissues showed epithelial lifting, rupture of secondary gill filaments, vacuole formation and hemocytic infiltration. The findings indicated that the isopod parasite,A. typus had a negative impact on fish health and appearance, causing economic losses to the small scale farmers/fishermen. This is the first reported record of the infestation of isopod parasite,A. typus on the Indian major carpC. ca...
Source: Journal of Parasitic Diseases - Category: Parasitology Source Type: research