Abdominal Scutes in the Round Herrings (Dussumieriidae)

Abstract

THE Dussumieriidae are usually distinguished from the Clupeidae or true herrings at familial (or sub-familial) level by their lack of abdominal scutes, although one or two modified pelvic scutes have been described (for example in Etrumeus¹). There have been records of fully scuted round herrings; but these all prove erroneous on closer examination. Thus Fowler² questioned the inclusion in Spratelloides of S. madagascariensis Sauvage because the original figure³ shows the ventral profile with unmistakable scutes. But Bertin⁴, in re-describing this species, is emphatic: “Cette carène n'existe pas”. Smith⁵, evidently accepting Sauvage's figure rather than Bertin's description, made S. madagascariensis the genotype of Pellonulops Smith, which he described as having 19–20 scutes (that is, both before and behind the pelvic fins). I have now examined one of the two syntypes of S. madagascariensis, and there are in fact no abdominal scutes other than the single pelvic scute found in all Dussumieriidae. The “hard, sharp keel on the thoracic region in front of the pectorals” in Gilchristella aestuarius (Gilchrist) mentioned by Barnard⁶ is not due to scutes, but is formed of the lower edges of the two cleithra meeting in the mid-line; in some specimens it is quite pronounced.