Population structure of exotic fish tilapia (Oreochromis mossambicus P. 1852) in Vallabhsagar reservoir - a large aquatic ecosystem on western ghats of India

Abstract

The present study was conducted to find out the population structure of the studied fish tilapia which provides the information on the exploitation pattern, existing growth and sustainability of the fish in the surrounding aquatic environment. The random fish scale samples (505 numbers) were collected at monthly basis during the month of November 2021 to April 2022 from different commercial fish collection center at Vallabhsagar reservoir, Gujarat for the proposed study of exotic fish tilapia (Oreochromis mossambicus). The findings of the study shows that fishes varied from 1+ to 5+ age classes and in which 4+ (29%) age group was dominated which followed by 2+ (26%), 3+ (25%), 1+ (12%) and 5+ (9%) of the total population. Moreover, bell shaped age pyramid of tilapia was observed by the balanced population growth due to static aquatic environment in Vallabhsagar reservoir, Gujarat. The increasing length and weight indicated that aquatic environment was favorable for Oreochromis mossambicus in study area may be due to abundance of energy rich food. This rare study in this particular area have been found very useful to evaluate the status of populations, scientific management of fisheries and stock assessment.