There has been considerable disagreement in the status of the Indo-Pacific species of Coilia Gray, 1831, with a long maxilla reaching beyond the gill-opening. Whitehead made a study of the various nominal species and provisionally grouped them into two species complexes namely, the mystus complex and the macrognathos complex, and provided a key to their separation.

In the present paper the taxonomic value of the free pectoral rays, abdominal scutes and gillrakers, earlier used for separating the various nominal species of the mystus complex are discussed. Coilia mystus (Linnaeus) is regarded as a distinct species with Coilia clupeoides Lacepede, Coilia playfairii McClelland, Coilia grayii Richardson, and Coilia lindmani Sleeker as junior synonyms. Coilia nasus Schlegel and Coilia ectenes Jordan and Seale, however, agree better with Coilia macrognathos Sleeker than with the above species. Further, Coilia mystus (Linn.), hitherto not reported from the Indian waters, is recorded for the first time from the Indian Seas on the basis of four specimens collected from the southeast coast of India. The specific status of earlier records of Coilia macrognatlios Sleeker from Thailand is discussed and its distributional range indicated.