東北地方太平洋沖から得られた日本初記録のヒレナガチョウチンアンコウ科魚類Caulophryne polynemaフサフサヒレナガチョウチンアンコウ（新称）

抄録

The rarely collected ceratioid anglerfish family Caulophrynidae, including the genera Caulophryne Goode and Bean, 1896 and Robia Pietsch, 1979, is widely distributed from the surface to the bathypelagic zone in the Pacific, Atlantic and Indian oceans. Valid Caulophryne species, characterized by the absence of an expanded escal bulb, presence of only 2 pectoral radials, extremely long dorsal- and anal-fin rays, 8 caudal-fin rays, neuromasts of the acoustic-lateralis system located at the tips of elongate filaments, an illicial length less than 130% of standard length (SL), 14–22 dorsal-fin rays, and 12–19 anal-fin rays, include Caulophryne jordani Goode and Bean, 1896 and Caulophryne pelagica (Brauer, 1902) from all three oceans, Caulophryne polynema Regan, 1930 from the Atlantic and eastern Pacific, and Caulophryne bacescui Mihai-Bardan, 1982 from the eastern Pacific. A single female specimen of C. polynema, collected over a bottom depth of 658–663 m off Iwate Pref., Pacific coast of northern Japan, on 9 October 2020, was distinguished from other congeners by the following combination of characters: illicium length 17.3% SL, with about 50 translucent filaments along its entirety; 19 dorsal- and 17 anal-fin rays. In addition, a parasitic male with degenerated dorsal, anal and pectoral fins, and eyes was found on the specimen. The specimen represents the first record of Caulophryne polynema from the western North Pacific, including Japanese waters, and northernmost record of the species in the Pacific Ocean. The new standard Japanese name “Fusafusa-hirenaga-chochin-anko” is proposed for the species.