Studies on reproductive biology of Mystus tengara (Ham.-Buch., 1822), a freshwater catfish of West Bengal, India

Studies on reproductive biology are essential to assess culture potential of a fish species. Mystus tengara is a popular food fish as well as preferred as an ornamental fish in West Bengal. Till date detailed report on reproductive biology of this fish species in the agro-climatic context of West Bengal is lacking. Therefore, the present work was aimed to study the detailed reproductive biology of Mystus tengara with an emphasis on sex ratio, length at first sexual maturity, cycle of gonadal maturation and spawning periodicity using standard methods. Results of the study revealed female dominance of the species over male in the population. However, the males showed earlier maturation than females. Five gonadal maturity stages namely immature, maturing, mature, ripe and spent were identified both for female and male fishes. Monthly study of gonadosomatic index (GSI), condition factor and mean ova diameter revealed that the breeding season for this fish species extended from May to September with a single spawning month in July. Total spawning behaviour along with synchronous oocytes development was also observed in this fish species.