RELATIONSHIPS BETWEEN FISH SIZE AND OTOLITH LENGTH IN THE WILD POPULATION OF CATFISH, CLARIAS MAGUR (LINN) (CLARIIDAE) IN RIVER GANGA BASIN, INDIA

Abstract

This study provides first basic information of the otolith of Clarias magur with details of shape and of its size with fish size in India. C. magur is an air breathing catfish, inhabiting river Gomti in Northern India and is presently listed as vulnerable species. Based on 170 specimens sampled in river Gomti, relationships were calculated between body length and weight, and between otolith length and body length of this species. All relations are statistically significant (p<0.05). Left and right otoliths do not lead to significantly different results. The otolith length is linearly related to fish length (total and standard) with least-squares regressions explaining about 87% of variation.