Description of three new species previously identified as Stolephorusbengalensis (Dutt & Babu Rao, 1959) or Stolephorusinsularis Hardenberg, 1933 and a re-description of S.bengalensis (Chordata, Osteichthyes, Clupeiformes, Engraulidae).

Abstract

Examination of numerous specimens characterised by predorsal scute, long maxilla, indented preopercle and pelvic scute lacking a spine and previously identified as Stolephorusbengalensis (Dutt & Babu Rao, 1959) or Stolephorusinsularis Hardenberg, 1933, revealed four distinct species, true S.bengalensis (distributed from the Bay of Bengal to Pakistan) and three new species, viz., Stolephoruseldorado sp. nov. (Taiwan to Java, Indonesia), Stolephorusdiabolus sp. nov. (Strait of Malacca, from Penang , Malaysia, to Singapore) and Stolephoruseclipsis sp. nov. (Bintan Island, Riau Archipelago, Indonesia). Characters separating the four species include numbers of gill rakers on each gill arch and vertebrae and pelvic fin and dorsal-fin ray lengths. Two molecular markers (mitochondrial cytochrome b and cytochrome oxidase I genes) demonstrated the distinction of three of the species examined morphologically and enabled a reconstruction of their phylogenetic relationships. Each species was genetically divergent from the others by 3.5%-7.7% mean uncorrected distance in the mitochondrial cytochrome oxidase I gene.