Morphometric comparison of the samples ofNemipterus japonicas populations from four different localities on the east coast of India is made. Analysis of covariance of morphometric characters reveals significance at 1% level for three characters. Character by character comparison of the means of locality-samples shows that there is clinal gradation in maxillary length (south to north) and pectoral length (north to south). The distance function (D)2 analysis shows that Kakinada is the farthest removed from other localities, and Visakhapatnam and Madras samples are nearer to each other. Paradeep sample occupied an intermediate position among the locality-samples. It is concluded that allNemipterus japonicus populations along the east coast of India are from a single genetic population, with restricted and localized movements confined to the areas where they are caught. The observed distinctness of Kakinada sample appears to be due to phenotypic variation under the influence of low salinity.