著者

木村 克也 津田 裕一 中山 直英

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.22-019, (Released:2022-11-14)

参考文献数

26

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The stomiid snaggletooth genus Astronesthes Richardson, 1845, including 49 valid species distributed in tropical to temperate waters of all oceans, is characterized by the following combination of characters: anal fin with 11–22 rays; maxillary teeth comblike, closely spaced, and slanting rearward; and photophores in the ventral series arranged in regular intervals. To date, 13 species of the genus have been reported from Japanese waters. A single specimen of Astronesthes (111.9 mm in standard length) was collected in December 2020, during a mid-water trawl survey conducted by R/V Shunyo-Maru in the vicinity of the Ogasawara Islands, Japan. Subsequently identified as Astronesthes gemmifer Goode and Bean, 1896, the specimen clearly differed from all congeners in having the following combination of characters: four premaxillary fangs in the main row (vs. 5–6); the posteroventral part of the terminal bulb of the chin barbel black (vs. usually not black or terminal bulb absent); and the last six VAV (photophores from the inner-pelvic space to the end of the row posterior to the anal-fin origin) located above the anal fin (vs. 1–4). Although A. gemmifer has been often recorded from the North Atlantic, records from the South Atlantic, Indian, and Pacific oceans are sparse. In the Pacific Ocean, the species has been recorded in Hawaiian waters from O‘ahu to the Hancock Seamounts, but not previously reported from Japanese waters, the present specimen representing the first Japanese record of A. gemmifer. The new standard Japanese name “Sumitsuki-tokagehadaka” is proposed for the species.

著者

矢頭 卓児 中山 直英 遠藤 広光

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.19-040, (Released:2020-03-24)

参考文献数

14

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The original description of Pterygotrigla cajorarori Richards and Yato, 2012, based on eight specimens from the western Pacific Ocean, including one Japanese specimen, indicated hyperostosis in the rostral projection, head bones (infraorbital, frontal, and parietal), post temporal spine, humeral spine, and the 2nd–4th first dorsal-fin spines, although variations in these characters were poorly documented. Thirteen specimens (including two paratypes) of P. cajorarori collected from southern Japan, the South China Sea, and Indonesia were found to vary individually in the degree of hyperostosis in the rostral projection, mesethmoid, lateral ethmoid, frontal, sphenotic, pterotic, and infraorbital bones, whereas the condition was not prominent in the parietal and posttemporal bones, or the humeral spines. However, hyperostosis was newly found in the 5th and 6th dorsal-fin spines and pelvic-fin spine. A detailed description of fresh coloration (previously unknown) in P. cajorarori is also given.

著者

鶴見 真治 清藤 秀理 中山 直英

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.22-016, (Released:2022-10-05)

参考文献数

31

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The rare barracudina Lestidium bigelowi Graae, 1967 was reported for the first time from the northwestern Pacific, based on four specimens collected from the vicinities of Okino-torishima Island, Japan, and Guam, at depths of 85–150 m. Previous records of the species had been limited to east of the Seychelles in the western Indian Ocean (type locality), the eastern Pacific off Colombia, and the southwestern Pacific off New Caledonia. Lestidium bigelowi is the only paralepidid species known to have six small, round, discrete mid-ventral luminescent organs, evenly spaced from the isthmus to near the anus, whereas in other species of the family, the luminescent organ is absent or represented by an elongate slender duct (s) extending along the mid-ventral line from the chest to the anus. The following characters are also useful to distinguish the species from its congeners: dorsal fin origin and outer pelvic-fin base more-or-less vertically level, anal-fin rays 28–30, vertebrae 80 or 81, predorsal fin length 54.3–56.5% of standard length (SL), and prepelvic fin length 53.7–56.3% of SL. Because L. bigelowi was previously known only from juveniles, the morphology of much larger individuals (72.3–123.7 mm SL) is described herein. Two specimens collected southwest of Okino-torishima Island represent the first record of L. bigelowi in Japanese waters (within the Exclusive Economic Zone). The new standard Japanese name “Botan-namehadaka” is proposed for the species, being derived from the button-like luminescent organs (“botan”) and the Japanese name for barracudina (“namehadaka”).