| 附註 |
Abstract: Over the last several decades it has become possible to collect in western New Guinea, now known as the Indonesian province of West Papua. Two collectors, Heiko Bleher and the second author, have collected at different times and brought back, amongst other species, some unusual specimens of a large hardyhead from Lake Lakamora (part of Triton Lakes complex, sometimes also known as Lake Laamora, at 3°41’S 134°17’E). The largest collected specimen of Sashatherina giganteus n. gen. n. sp. was measured to be 180 mm TL (total length) which far exceeds the largest known Old World species (eg. Atherinomorus species) and unconfirmed reports suggest that these fish may grow as large as 350 mm TL. This 'giant' hardyhead is also unique in several other characters: it has very numerous small scales with a maximum midlateral scale count of 60 and up to 17 rows of transverse scales. Although there is usually a high correlation between the midlateral scale count and the number of vertebrae, this is not the case in this species. All of the scales are crenulated, another unique feature of this new genus. The lower jaw is very pronounced and protruding beyond the anterior border of the premaxilla. The shape of the pectoral girdle is also different to other known species. The eye in this species is quite small. Sashatherina giganteus n. gen. n. sp. is closely related to the genus Craterocephalus on the basis of osteological comparison. The genus Craterocephalus is represented by 6 species in New Guinea and by 18 species and one subspecies in Australia, in freshwater, estuarine and marine environments. One species, C. laisapi, is also found in East Timor. Sashatherina n. gen., on present knowledge, is monotypic and distinct on the basis of characters described. |