Leptagonus decagonus

Author: Schneider, 1801

Leptagonus decagonus Schneider, 1801

Status in World Register of Marine Species:
Accepted name: Leptagonus decagonus (Bloch and Schneider, 1801) (updated 2009-06-25)

Diagnosis. two dorsal fins. No barbels on snout tip, two barbels on ventral surface of snout rudimentary or absent. Maxillary barbels (4) reaching preopercular ridge. No barbel on lower jaw tip. Short nasal tube, never reaching upper jaw. Nasal bones attached to each other anteriorly; free nasal margin serrated; an enlarged rostral plate absent, on ventral surface of snout tiny plates or tubercles. Nasal bone projecting forward beyond upper jaw. No ethmoidal spine. Nasalethmoid ridge smooth Second infraorbital spine with a supplimentary spine or knob. Gill menbranes united, widely fused with isthmus. The first dorsal fin with (5)6-8 spines, the second with (5)6-8 soft finrays; pectoral fin large, with 15-17 finrays; anal fin short, with 6-8 finrays. 21-28 lateral line plates (Kanayama, 1991). Colour: body brownish-grey, with a few dark cross-bars or blotches, lower parts lighter. Mouth and gill cavities, and peritoneum pale. Size: to 21 cm TL, usually 15-20 cm

Habitat: benthic on muddy or sandy bottoms at 120-475 m (rarely to 600 m, but to 930 m in Baffin Bay), at temperatures of 4.4 °C to -1.7 °C and salinities of at least 34.5‰. Food: pelagic and bottom crustaceans (copepods, schizopods, amphipods) and polychaetes. Reproduction: eggs demersal (480-1,750 of about 2 mm); spawns in June and July off the Murman coast and in May and June off Iceland; pelagic fry recorded in May (Iceland).

Distribution: northern coasts from Spitsbergen and Finmarken coasts eastwards (White Sea, Barents Sea, northern part of Kara Sea), also northern and eastern part of Iceland and south-eastern coasts of Greenland. Elsewhere, Greenland to Labrador and Newfoundland, Okhotsk and Bering Seas.

Eggs, larvae and young stages. J. Schmidt, 1908: 7, pl. I (fig. 6-t0).
Otoliths (sagitta). W. Schmidt, 1968: 58, pl. 12 (fig. 163).