
The study was conducted during September to February months in the laboratory to study the external morphological characters for identifying the sex of Anabas testudineus during non-breeding season. Monthly sampling was done from the rearing stock for the study. For the identification of sex two methods were adopted. First one was observation of sex through external morphology and second one was confirmation of gonad through dissection. The seasonal development of the gonads was also studied morphologically. In the present study a trial was done to identify the sex through external observation on the basis the colour of the body, belly structure and vent. During the study it was found that all the above criteria were not sufficient to identify the sex of A. testudineus during non-breeding season, because no remarkable difference in the above morphological characters was noticed in male or female fish. Therefore, it is concluded that during non-breeding season the identification of sex in A. testudineus is quite difficult on the basis of external morphology, which needs further investigation.