A New Species of the Anchovy Genus Stolephorus Lacepède 1803 from North Sumatra, Indonesia, and Redescriptions of Stolephorus pacificus Baldwin 1984 and Stolephorus teguhi Kimura, Hori and Shibukawa 2009 (Teleostei: Clupeiformes: Engraulidae).

Abstract

Stolephorus leopardus sp. nov. is described here, and Stolephorus pacificus and Stolephorus teguhi are redescribed. Those three species are distinguished among congeners by the presence of more than 30 gill rakers on the lower limb of the first gill arch and a short maxilla, posteriorly just reaching the anterior border of the preopercle. Stolephorus pacificus and S. teguhi have rarely been reported since they were originally described, and therefore detailed morphological data and further diagnostic characters are provided. Stolephorus leopardus, in turn, is described based on four specimens collected on Nias Island, North Sumatra Province, Indonesia. The new species can be distinguished from S. pacificus and S. teguhi by a shorter pectoral fin (15.6-16.3% of standard length vs. longer than 16.5%), a longer snout (4.7-4.8% of standard length vs. < 4.5%), and an intermediate number of total gill rakers on the first gill arch (63-68 in S. leopardus vs. 57-63 in S. pacificus and 72-82 in S. teguhi). In addition, the new species differs from S. pacificus in having a dark line on the dorsum (vs. line absent), numerous melanophores laterally on the head (vs. a few melanophores on the snout and mandible tips), and higher counts of branched anal-fin rays [19-21(modally 19) vs. 17-19 (18)]. Stolephorus leopardus is further distinguished from S. teguhi by a shorter anal-fin base (22.4-22.5% of standard length vs. 22.7-25.3%).