Notes on eggs, larvae and juveniles of fishes from Indian waters. VI. Genus Auxis Cuvier. VII. Sarda orientalis (Temminck & Schlegel)

Abstract

There are under this genus two distinct species distinguished mainly by the nature of their corselets. In the first species, A. thazard the corselet is short, abruptly constricting immediately behind the vertical from the hind end of the first dorsal, whereas in the second species it gradually tapers and extends to well behind the second dorsal. Bleeker described A. tapeinosoma (Bleeker, 1854), and A. thynnoides (Bleeker,. 1855) from Indonesian waters and these have been relegated as synonyms of A. thazard by Beaufort (1951). Wade (1949), while working on Philippine tunas, recognised the presence of a long corseletted form distinct from the short corseletted form and fixed the identity of the former as A. tapeinosoma, a name used by subsequent workers (Herre and Herald 1951; Herre, 1953; Jones, 1958). Recently Matsumoto (1959) after a critical study of the original descriptions and examination of the type specimens of both A. tapeinosoma and A. thynnoides found that the former is a short corseletted form and as such is synonymous with A. thazard, while the latter is a long corseletted form. Therefore in this account A. tapeinosoma is relegated as a synonym of A. thazard and the long corseletted form will be referred to as A. thynnoides. Both the species are distributed in the Indo-Pacific but the former appears to be better known and from a wider area than the latter.