A new silverside, Doboatherina palauensis (Atheriniformes: Atherinidae) from the Palau Islands in the West Pacific

Abstract

A new atherinid fish, Doboatherina palauensis, is described based on the holotype and 31 paratypes, 36–51 mm in standard length, collected from the marine lakes and outer lagoon in Mecherchar Island, Republic of Palau. The new species can be distinguished from all congeners by a short, blunt ascending process of the premaxilla (height about twice maximum width), premaxilla with a single lateral process, posterior upper margin of dentary with a small process, palatine toothed, no crenulation along posterior margin of lateral and predorsal scales, smaller eye (diameter 9.2–11% of standard length), 37–39 midlateral scales, 38–41 total vertebrae, narrower midlateral band (about 1/2 width of midlateral scale, its upper and lower margins not reaching to upper and lower margins of midlateral scale row at the level of anal-fin origin, respectively). The new species resembles Doboatherina aetholepis (Kimura, Iwatsuki and Yoshino 2002), Doboatherina bleekeri (Gunther 1861), Doboatherina valenciennei (Bleeker 1854) and Doboatherina woodwardi (Jordan and Starks 1901) in sharing a comparatively slender body in the genus Doboatherina. The former is distinguishable from D. aetholepis by having only a short spatular outgrowth on posterior margin of predorsal and/or interdorsal scales or almost lacking the outgrowth (vs. a long spatular outgrowth on posterior margin of most predorsal and interdorsal scales in D. aetholepis) and narrower midlateral band (lower margin not reaching to lower margin of midlateral scale row vs. reaching), from D. bleekeri and D. valenciennei by lacking crenulated lateral and predorsal scales (vs. having crenulated lateral and/or predorsal scales) and a single lateral process on premaxilla (vs. two processes), and from D. woodwardi by having lower ascending process (height about twice maximum width vs. three times) and a single lateral process on premaxilla (vs. two processes). Doboatherina bleekeri has more numerous total vertebrae (42–47) than D. palauensis (38–41).