Die Otolithen der Macropodus‐Arten (Pisces, Belontiidae)

Abstract

The Otoliths of the Species of the Genus Macropodus (Pisces, Belontiidae)The sagittae of the three Macropodus species opercularis, concolor and ocellatus (formerly chinensis) as well as their hybrids are described and sketched. Characteristic for the species of the genus Macropodus are sagittae with a prominent rostrum, a deep exisura ostii, and a projected predorsal angle. The sligthly S‐sharped cauda is the largest part of the sulcus while the ostium is not completely developed. The cauda has only an anterior opening. But in some cases there is a shallow channel or groove connecting the end of the cauda with the posterior notch. The crista superior is prominent while the crista inferior shows only a sharp edge. A caudal colliculum can be discerned on some otoliths.Adult males of the three species can be recognized on the basis of their otoliths as follows: The sagittae of M. concolor are the largest. Their dorsal rim is frequently very deeply furrowed or notched, a posterior notch is mostly well developed. The sagittae of M. opercularis are mostly circular in shape and their rims are not very deeply furrowed, but only waved. The sagittae of M. ocellatus are the smallest with an inferior rostrum, frequently with smooth rims and often almost trapeze shaped.The results are partly in conformity with the evidences given by LIEM (1963) about the otoliths of the Belontiidae but a colliculum as well as parts of an ostium – not identified by LIEM in these fishes – were found by the author.The marked differences between the sagittae of M. opercularis and M. concolor support the species level of the latter, a fact, which has been discussed long.