Pogonophryne tronio, a new species of Antarctic short-barbeled plunderfish (Perciformes: Notothenioidei: Artedidraconidae) from the deep Ross Sea with new data on Pogonophryne brevibarbata

摘要

Antarctic barbeled plunderfishes of the genus Pogonophryne are the most speciose notothenioid group, comprising about 20 poorly known recognized species. The interspecific systematics within the genus is complex, because the various species vary little morphologically. One of these previously unknown forms captured as by-catch of the Antarctic toothfish (Dissostichus mawsoni) fishery during the Antarctic summer 2009-2010 in deep waters of the western Ross Sea is described herein as new species Pogonophryne tronio. The description is based on 2 adult specimens, captured at depths 900-1,015 m: the holotype (male, 290 mm TL, 234 mm SL), paratype (female, 315 mm TL, 260 mm SL). This species, a short-barbeled form of the dorsally spotted "P. mentella" group of species, is compared morphologically to the closely related P. brevibarbata and P. ventrimaculata, using type specimens of both species. P. tronio sp. n. is characterized by the following combination of characters: a short (about 10-12 % SL), slender, tapered and bicolored (dark basally, light distally) mental barbel without a conspicuous terminal expansion; tip of barbel slightly flattened and covered by short tapered finger-like processes basally and flattened, leaf-like processes distally; a slightly protruding lower jaw; a relatively low (about 18 % SL) second dorsal fin lacking the elevated anterior lobe occurring in males of some species in the genus, sharply striped pectoral and caudal fins; the dorsal surface of the head and the area anterior to the first dorsal fin covered with large dark-brown blotches and spots.