Abstract:
Osteological differences between spotted, spinner and striped dolphins, Genus Stenella in Thai Waters were studied. All samples stranded along Andaman coast consisting of 13 spotted dolphins, 17 spinner dolphins and 22 striped dolphins. External, skull and skeleton measurements by vernier caliper (point-to-point) were performed. It was found that the proportion of snout to melon lenght and total length can separate spinner dolphin from spotted and striped dolphin. From various proportions of skull analyzed by cluster analysis, it was found the proportions that separate three species were proportion of rostrum width at base to condylobasal length, proportion of skull height to parietal width, proportion of atlas height to atlas width and proportion of lateral process length of atlas to atlas height. From age analysis it was shown that spotted dolphins are 17-35 years old having 187-212 cm length, spinner dolphins are 5-27 years old having 167-190 cm length and striped dolphins are 3-26 years old having 181-228 cm length.