Morphometric characteristics of the spinner dolphin Stenella longirostris were analysed based on samples (n=16) collected from two centres along the east coast of India (Bay of Bengal). The total length of the samples ranged from 84 to 170 cm. Of the 11 characteristics related to the anterior part of the body, the ratio of 10 characteristics to the total length is higher for calf male than that of adult male. There are also a few conspicuous differences between adult male and female. The Bay of Bengal form appears to differ from the other forms of world oceans, confirming that the morphometric characteristics of the spinner dolphin vary greatly geographically.

Stenella longirostris, spinner dolphin, sexual dimorphism, phenotype, Bay of Bengal