Seasonal Dynamics and Prevalence of Helminth Infection in Freshwater Fishes of Kelzar Dam, Maharashtra, India

Abstract

Helminth parasites are one of the major challenges affecting the health, growth, and productivity of freshwater fishes, leading to economic losses in fisheries. This study investigated the prevalence, seasonal variation, and host-related factors associated with helminth infections in freshwater fishes from Kelzar Dam, Maharashtra, India. A total of 468 fishes representing eight species were collected and examined between June 2021 and May 2025. Among them, 176 fishes were infected, giving an overall prevalence of 37.6%. Six helminth species belonging to four major groups, namely nematodes, trematodes, cestodes, and acanthocephalans, were identified. Infection varied among fish species, with the highest prevalence recorded in carnivorous fishes (47.9%), followed by omnivorous (30.8%) and herbivorous (30.5%) fishes. Seasonal analysis showed that infection was highest during the monsoon season (54.5%) and lower during summer (28.8%) and winter (26.3%). Most parasites were recovered from the intestine (68.0%), followed by the body cavity (12.3%), stomach (11.0%), and liver (8.7%). The parasite community exhibited moderate diversity, with a Shannon–Wiener diversity index (H′ = 1.52), indicating a relatively stable host–parasite relationship. Statistical analysis showed significant associations between infection prevalence, season, and feeding habits (p < 0.05). These findings provide baseline information for fish health monitoring and support sustainable fisheries management and freshwater ecosystem conservation.