Seasonal Dynamics and Host-specific Infection Patterns of Intestinal Cestodes in Economically Important Freshwater Fishes of Chorakhali Dam, Dharashiv (Formerly Osmanabad), Maharashtra, India

Abstract

Aims: This study investigated the seasonal dynamics and host-associated infection patterns of intestinal cestode parasites infecting economically important freshwater fishes from Chorakhali Dam, Maharashtra, India. The objectives were to determine the prevalence, mean intensity, and seasonal variation of cestode infections and to evaluate host–parasite associations under natural environmental conditions. Study Design: A field-based observational parasitological study. Place and Duration of Study: Chorakhali Dam, Dharashiv (formerly Osmanabad) District, Maharashtra, India, from June 2022 to April 2026. Methodology: A total of 237 freshwater fishes representing commercially important species were collected from different sampling sites and examined for intestinal cestode infections using standard parasitological techniques. Recovered parasites were fixed, stained, mounted, and identified using established taxonomic keys. Parasitological indices, including prevalence, mean intensity, mean abundance, and host-associated occurrence, were calculated. Seasonal differences in infection were analysed using the Chi-square test and one-way ANOVA, with statistical significance accepted at P < 0.05. Results: Among the 237 fishes examined, 108 (45.57%) were infected with intestinal cestodes. Infection prevalence differed significantly among seasons (P < 0.05), with the highest prevalence recorded during summer (60.26%), followed by winter (44.30%), and the lowest during the monsoon season (32.50%), consistent with the seasonal distribution presented in Table 3. Mastacembelus armatus exhibited the highest infection prevalence and was predominantly infected with Senga spp., whereas Circumoncobothrium spp. occurred mainly in Channa species. Mean parasite intensity and abundance were also significantly higher during summer (ANOVA: F = 14.27, P = 0.001), suggesting favourable environmental conditions for parasite transmission. Conclusion: The present study demonstrates that intestinal cestode infections in freshwater fishes from Chorakhali Dam exhibit pronounced seasonal variation and distinct host-associated occurrence. Summer represents the peak transmission period, whereas monsoon conditions are associated with reduced infection. These findings provide baseline information for fish health surveillance, parasite management, and sustainable inland fisheries in Maharashtra.