Impact of helminth parasites on length and weight relationship in catfish Heteropneustus fossilis (Bloch, 1794) of Gomti river, Lucknow.

Abstract

Fishes are infected with helminth parasites that affect their normal physiology, making them vulnerable to diseases that lower their productivity, and high fish mortality. Some helminths, such as trematodes, nematodes, cestodes, and acanthocephalans, heavily parasitize freshwater fish, affecting fish growth and health conditions. Therefore, the present study was carried out to investigate the length and weight relationship (LWR) and condition factors between infected and non-infected freshwater catfish Heteropneustus fossilis. The medium-length range of males was more infected with Trematodes and Cestodes, while no Nematode infection was found in the males. The medium-length range of females was more infected with trematode, cestode, nematode, and Acanthocephala, and females were comparatively more infected than males. The results showed that the growth of infected catfish species exhibited negative allometry because the regression coefficient "b" obtained was < 3. The statistical analysis showed that there was a significant difference between infected and non-infected fish in the b value. Moreover, the highest "b" value (2.24) was recorded in non-infected fish as substantial (p < 0.05) positive allometry. The present research is beneficial as it offers pertinent data for studying fish biology, assessing the condition of fish in their habitat, and evaluating parameters about population dynamics.