2026-09-18 北海道大学,東海大学
新種ホソオホラアナゴ Ilyophis fukuiiの鮮時写真
＜関連情報＞
- https://www.hokudai.ac.jp/news/2026/09/10-18.html
- https://link.springer.com/article/10.1007/s10228-026-01082-x
深海性ホラアナゴ科魚類リュウキュウホラアナゴIlyophis brunneus Gilbert, 1891から見出されたリュウキュウホラアナゴ属の隠蔽種とその新種記載 A new cryptic species of the deep-sea eel genus Ilyophis (Synaphobranchidae) discovered within Ilyophis brunneus Gilbert 1891
Fumihito Tashiro & Munehiro Takami
Ichthyological Research Published:16 September 2026
DOI:https://doi.org/10.1007/s10228-026-01082-x
Abstract
A new species of the deep-sea eel genus Ilyophis (Synaphobranchidae), Ilyophis fukuii sp. nov., is described based on 20 specimens (120–463 mm in total length: TL) collected from the northwestern Pacific Ocean off southern Japan, mostly at depths greater than 1,500 m. The species has previously been identified as Ilyophis brunneus Gilbert 1891, a circumglobal species distributed in the Atlantic, Indian and Pacific oceans. The new species is distinguished from congeners by the following combination of characters: slender tail (body depth at caudal region 22.4–32.6% of snout length), 145–153 total vertebrae (including 107–114 caudal vertebrae), 3 supraorbital pores (absent above eye), 5 infraorbital pores (rarely 6, with an additional pore behind eye), frontal pores absent, supratemporal pores absent (rarely 1 present), body scales elongate, rod-like, becoming oval near tail tip, lateral-line canal length 83.3–89.5% of total length (in specimens ca. >250 mm TL). Based on morphological examinations and DNA barcoding of the COI gene region, the new species is also inferred to occur in the North Atlantic Ocean and off Tasmania, Australia.
