著者

伊藤 玄 古屋 康則 堀池 徳祐 向井 貴彦

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

vol.67, no.1, pp.41-50, 2020-04-25 (Released:2020-05-02)

参考文献数

39

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An examination of the genetic population structure of Cobitis minamorii tokaiensis in central Honshu Japan, based on mitochondrial DNA nucleotide sequences in the cytochrome b region, revealed that the subspecies is subdivided into three regions (West-Shizuoka, Mie, and Aichi-Gifu) on the evidence of haplotype distribution and pairwise Φst among populations. However, the phylogenetic analyses indicated that the haplotypes in the three regions belong to the same haplotype group, suggesting that C. m. tokaiensis dispersed following the interconnection of paleo-river systems within relatively recent geological time, and subsequently differentiated in several areas. Because of its genetic characteristics, the three regions are important for conservation of the subspecies’ genetic diversity.

著者

明仁 坂本 勝一

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.36, no.1, pp.100-112, 1989-06-28 (Released:2011-02-23)

参考文献数

16

被引用文献数

3

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The striped goby was characterized by having more than 50 scales in a longitudinal row and 2 black longitudinal bands from the head to the tail. It has been regarded as 1 species since Tomiyarna (1936) grouped several nominal species into one, Tridentiger trigonocephalus (Gill, 1858). But detailed study has revealed that it can be classified into 2 separate species, T. trigonocephalus and Tridentiger bifasciatus Steindachner, 1881, on the basis of the difference mainly in the forms of the sensory canals and pectoral fins and in the coloration. T. trigonocephalus has been collected from Hokkaido to Kyushu in Japan, and in Korea, China, and Hong Kong abroad. It has immigrated into both California, U.S.A., and New South Wales and Victoria, Australia. T. bifasciatus has been collected in the same area as T. trigonocephalus in Japan, and in the Soviet Union, Korea, China, and Taiwan abroad. Both species inhabit brackish and sea water with stony bottoms, and are often found in the same place. However, T. trigonocephalus has seldom been found in very dilute brackish water, and T. bifasciatus has not been found in undiluted sea water. The type specimen of T. trigonocephalus has not been found, but the identification to T. trigonocephalus was decided on the basis of the closeness of the numbers of the 2nd dorsal and anal fin rays to those of the original description, which were 14 and 13, respectively. In addition, the type specimen was collected in the port of Hong Kong, where the water is not diluted and is unlikely to be suitable as habitat for T. bifasciatus.

著者

明仁親王

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.18, no.2, pp.57-64, 1971-09-15 (Released:2010-06-28)

参考文献数

5

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Among the 109 species of gobiids listed at the end, the supratemporals were found in six species: five out of sixteen species in Group 1 and one species in Group 3 (Table 1).No supratemporal was found in Group 2 and Group 4 (for the characteristics of the four groups, see Prince Akihito, 1969). These bones were found between the sensory canal groove of the pterotic and the post-temporal (Fig.1).These species had a continuous sensory canal from the anterior tip of the head to the area of the supratemporals and the supratemporal canal.The supratemporals consisted of three pieces, anterior, median, and posterior, which I named without particular consideration for the homology of Tominaga's (1968: 59) anterior and posterior supratemporals on the Pempheridae.They were all separated in three species, Oxyeleotris marmorata (Figs.1.A and 2.A), Bostrichthys sinensis (Fig.2.C), and Ophiocara porocephala (Fig.2.D), and each piece usually had one nerve foramen.In two species of the genus Butis, B.butis (Fig.2.E, F) and B. gymnopoma (Fig.2.G), the median and posterior supratemporals were fused. In Xenisthmus clarus (Figs.1.B and 2.H) the anterior and median supratemporals were fused.The fused bone had two nerve foramina.Wide individual variations were observed in the shape, including loss of a bone (Fig.2.B), separation of a fused bone, loss of a nerve foramen, or an additional foramen on the upper lateral side.The presence or absence of supratemporals was dependent on the presence or absence of the sensory canal on that part, except in the cases of Bathygobius petrophilus and Syciopterus japonicus (both belonging to Group 4) which had a continuous sensory canal but no supratemporal canal. Although the presence or absence of sensory canals was sometimes inconsistent, it seems that the systematic value of the supratemporal is signifcant, considering that the most unspecialized Oxyeleotris marmorata and Bostrichthys sinensis (which are the only species having a suborbital) have the most complete sensory canal systems with three supratemporals.

著者

清水 孝昭

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

vol.61, no.1, pp.36-40, 2014-04-25 (Released:2016-05-22)

参考文献数

61

著者

後藤 晃

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.32, no.3, pp.359-362, 1985-11-28 (Released:2010-06-28)

参考文献数

7

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淡水カジカ類の一種カンキョウカジカの第1背鰭棘と第2背鰭軟条にそれぞれコード番号を符した後, それらを組み合わせて除去することによって個体識別する方法を考案し, またそれを自然河川個体群に適用することによって有効性を検討した.その結果, 本マーキング法は体長50mm以上の個体に容易に用いることが出来, 魚の運動能力にほとんど影響を与えることがなく, 組み合わせによっては数千個体の識別が可能であり, かつ, 永久マークとなるので極めて有効なマーキングの方法であると判断された.

著者

塚原 博

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.3, no.3-5, pp.139-143, 1954-06-30 (Released:2011-02-23)

参考文献数

5

被引用文献数

1

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In this paper the writer deals with the breeding habits of the fresh-water suker, Abbottina rivularis (BASILEWSKy), a small cyprinoid fish. The usual habitats of the fish are the slow streams with muddy bottom. The spawning season lasts from beginning of March to early May. In the breeding male numerous horny tubercles appear on the snout, anterior part of the cheek, pre-opercle region and on the outer margin of pectoral fins. Dusky and yellow nuptial coloration also appears on the body.The male fish prepairs a nest on the muddy bottom in the shape of a round, shallow depression, 20-40 cm. in diameter and 3-5 cm. in depth. In this nest about 2, 000-4, 000 eggs are deposited, over which the male parent fish eagerly keeps guard until the hatched larvae attain the end of the post-larval stage, about 10mm. in total length. The egg is spherical in shape and about 1.4mm. in diameter, with a jelly-like coating of about 1mm. in thickness. The surface of the jelly coat is covered with mud.

著者

片野 修 馬場 吉弘 大原 均 河村 功一 佐藤 正人 熊谷 雅之 竹内 基 伊藤 正一 富樫 繁春 井上 信夫

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

vol.61, no.2, pp.97-103, 2014-11-05 (Released:2016-12-25)

参考文献数

28

被引用文献数

2

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The distribution of Nipponocypris temminckii was investigated in 24 rivers in Nagano, Niigata, Yamagata, Akita, Iwate, and Aomori Prefectures, the species being collected at seven study sites. Amongst non-benthic fishes, N. temminckii was exclusively dominant in two rivers. Supplementary records of the species in Nagano, Niigata, Akita and Iwate Prefectures were also described. Rivers in which investigations had been conducted over two or three years showed an increasing proportion of N. temminckii, indicating successful colonization of the species.

著者

谷内 透

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.21, no.3, pp.145-152, 1974-12-28 (Released:2010-06-28)

参考文献数

17

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3種のシュモクザメが本邦西南海域に分布している, それらはヒラシュモクザメ, Sphyrma mokarron (Rüppell), シロシュモクザメ, S.zygaena (Linnaeus), アカシュモクザメ夢S.lewini (Griffth and Smith) である.なお, 上述の和名は本研究で改めて提唱するものである.また, 3種の同定のための検索表を作成した.3種の浮延縄による漁獲データからみると, アカシュモクザメが最も数が多く, ついでシロシュモクザメで, ヒラシュモクザメが一番少なかった.釣獲率でみた密度分布によると, 調査海域では3種ともほぼ分布が九州の南端, 南西諸島, 台湾を結ぶ線より浅い海域に限られているのがわかった.また, 密度分布の季節変化からみて, 3種とも大規模な南北回遊をしている徴候が認められなかった.いろいろな証拠から夢3種の集団の主力はほぼ東支那海域に棲息しているものと推定された.

著者

尼岡 邦夫 武藤 文人 三上 敦史

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.48, no.2, pp.109-112, 2001-11-26 (Released:2010-06-28)

参考文献数

8

被引用文献数

1

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In 1993 and 1999, a number of specimens of a poecilid fish collected from a drainage area of the hot spring at Kojyohama, Shiraoi-cho, Shiraoi-gun, southern Hokkaido, Japan was identified as Poecilia sphenops. Identifications were based on males having elongated pelvic-fin tips, in having the dorsal-fin origin posterior to a vertical through the pelvic-fin base, 9-10 dorsal fin rays, no horizontal pigment band and ocellus on the body, no opening of the cephalic sensory canal on the snout, and many tricuspid teeth in the inner row of teeth on the upper jaw. It is believed that small fish were introduced into this area longer than 20 years ago to assist in reducing mosquito populations. At present, high density schools of these small fish were observed swimming throughout the drainages. This report represents the record of habitation and natural breeding of this species in Japan.

著者

中島 東夫 川原 大 高松 史朗

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.34, no.1, pp.66-70, 1987-06-10 (Released:2011-02-23)

参考文献数

7

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1974年6月3日から12月3日まで, 大分生態水族館の11尾のコバンザメEcheneis naucratesを展示している水槽で, 水温が25℃以下に低下した時以外は, 連目消灯後, 産卵行動がみられ, 直径2.6mmの浮遊性卵が1日平均して約500個産卵された.産卵行動は, オスがメスの腹部を吸盤で刺激し, メスは産卵しそうになると水槽中央上方に泳ぎ出し, 4-6尾のオスがそのメスを追い, 吸盤で水面に押し上げ, 同時に産卵と放精が起こるとい'うものであった.6月15日にふ化した70尾の仔魚の飼育を試み, 9月1日まで26尾の成育が認められ, 並行してその時の仔稚魚の行動を吸盤により吸着がみられる時期まで記録した.仔稚魚の形態変化における特徴は, 吸盤の形成と尾鰭の伸長であり, それらの変化に対応して行動もいちじるしく変化した.吸盤が出現しはじめるまでの時期は尾鰭を折りたたみ, 斜め上を向いて泳ぎ, 餌をとる時には尾鰭を開き, 体をS字型に曲げ, 尾鰭をあおり, 体をまっすぐにして動物プランクトンに突進し, 餌をとった瞬間には, 尾鰭は元の状態に戻していた.吸盤が出現しはじめると, 尾鰭を折り曲げて水槽底で立ち, 吸盤の形成が完成すると, 体をあお向けにしたり, 腹ばいになったりして, 水槽底に横たわるようになった.もっとも成長の早い個体でふ化後35日, 体長55mmで水槽内に設置したパイプや板に吸着するようになった.

著者

川瀬 成吾 中江 雅典 篠原 現人

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.22-028, (Released:2023-05-15)

参考文献数

61

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The fish collection built up by Chiyomatsu Ishikawa (1860–1935), a Japanese zoologist who investigated the fish fauna of Lake Biwa in the 1890s, was reassessed for the first time in many years, and found to provide an important insight into the fish fauna of the lake at the end of the 1800’s. Now held in the National Museum of Nature and Science, Tsukuba, Japan, the collection includes 1,795 specimens (110 lots) collected from 12 sites in Lake Biwa and adjacent areas (i.e., Hikone, Imazu, Kaizu, Kaminyu, Lake Yogo, Maebara (= Maibara), Matsubara, Nagahama, Omi-Hachiman, Seta River, Shiotsu and Zeze). Thirty-three species, including 10 endemic species/subspecies, in 11 families were identified, including the type series of Pseudogobio zezera (=Biwia zezera). The majority of specimens were included in the following 7 species: Tanakia lanceolata, Acheilognathus tabira tabira, Candidia sieboldii, Ischikauia steenackeri, Sarcocheilichthys variegatus microoculus, Tachysurus nudiceps, and Plecoglossus altivelis altivelis (landlocked type). Such species are now seen infrequently along the lake foreshore (except for P. a. altivelis), the collection indicating a formerly rich fish fauna before the establishment of artificial influences (e.g., concrete revetments, invasion of alien species such as Micropterus nigricans and Lepomis macrochirus, and artificial control of water levels by the Seta River Weir). Although the occurrence of Acheilognathus longipinnis and Sarcocheilichthys variegatus variegatus in Lake Biwa has been unclear for a long time, examples of those species/subspecies in the collection provided evidence of their past distributions in the lake. Importantly, the collection sets a benchmark for any restoration of the past fish fauna of Lake Biwa.

著者

Daniel M.Cohen

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.26, no.3, pp.225-230, 1979-12-15 (Released:2011-07-04)

参考文献数

16

被引用文献数

1

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イソアイナメ属Lotellaは,上顎外側に1列の大きな歯があり,小さな歯からなる内側の歯帯と分離し,発光器が無い.チゴダラ属Physiculusの上顎歯は大きさが一様(大小の歯が分離しない)で,腹部発光器が有る。ホソダラはイソアイナメ属に移され,南支那海まで分布域が拡大された。イソアイナメムphycis(属の模式種)と,ホソダラL.tosaensisの簡単な記載を行った.エゾイソアイナメPhysiculus maxmowicziはチゴダラ属に移され,多分チゴダラP.japonicusのJunior synonymである.

著者

鈴木 亮

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.4, no.1-3, pp.50-58, 1955-09-30 (Released:2010-06-28)

参考文献数

19

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(1) ドジヨウとフナ又はキンギヨの交配を行い、交雑卵の死亡率を調べ、孵化した存魚の内部及び外部の形態について観察を行つた。(2) 科間交雑卵は、正常卵に比べて嚢胚期と孵化期に著しい死亡率を示し、更に孵化した仔魚は、孵化後3~20日ですべて斃死した。(3) 多くの交雑仔魚は尾部、腹部、心臓、前腎系統、脊索、血管などが発生障害を受けた。(4) 前腎輸管や、前腎室が発生障害を受けた交雑仔魚はedemaになつたが、その障害を受けなかつたものはedemaにはならなかつた。このことからedemaの成因は前腎機能に関係しているものと思われる。(5) 交雑仔魚に於ては、前腎輸管の異常肥大をしているものがあり、これは一側部の前腎系統が肛門の附近でつぶれているか、或はそれが欠如している場合に限つてみられた。しかし、前腎室がつぶれていた場合には、このような肥大は見られなかつた。(6) edemaになつた仔魚は、孵化後3~5日ですべて死亡したが、edemaにならなかつたものは、孵化後10~20日間も生存することができた。このことから、edemaは交雑仔魚の一つの死因となつているものと考えられる。(7) 交雑仔魚は正常仔魚に比べて、心臓の衰弱、游泳及び索餌不能といつたようなことが観察された。従つて交雑仔魚の死因は単にedemaのみではなく、それ以外にも幾つかのことが関与しているものと思われる。

著者

中尾 遼平 入口 友香 周 翔瀛 上出 櫻子 北川 忠生 小林 牧人

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

vol.64, no.2, pp.131-138, 2017-11-25 (Released:2018-06-19)

参考文献数

28

被引用文献数

2

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Genetic disturbance in Japanese wild medaka populations (Oryzias latipes species complex) has resulted mainly from artificial introductions from geographically distinct populations or of commercial varieties, especially an orange-red body color variety (himedaka). Because the extent of genetic introgression within a single water body has remained unclear, the genetic population structure of wild minami-medaka Oryzias latipes in the Nogawa River, a tributary of the Tamagawa River system in Tokyo, Japan, was surveyed using three DNA markers (cytb and ND2 genes on mitochondrial DNA and b-marker on nuclear DNA) to evaluate the extent of introgression throughout upper and lower reaches. Genotypes originating from himedaka were detected at all sites surveyed. Although different genetic composition of introgressed mitotypes among some sampling sites suggested multiple introductions of non-native populations, high dispersal rates of introgressed genes could not be rejected as a cause of wide-spread introgression. Based on this study, appropriate management strategies for the genetic conservation of wild medaka populations are discussed.

著者

望月 健太郎 伊東 正英 本村 浩之

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.22-009, (Released:2022-06-03)

参考文献数

26

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A single specimen (153.7 mm total length) of large congrid leptocephalus, collected at a depth of 400 m off Kuro-shima Island, Osumi Islands, Kagoshima Prefecture, Japan, was subsequently identified as Congriscus maldivensis (Norman, 1939), having the following combination of characters: 46 lateral-line pores before anus; 149 total vertebrae, including 46 abdominal vertebrae; maximum body depth 27.2% of total length (TL); pectoral fin length 40.6% of head length; highest margin of head profile anterior to pectoralfin base; snout rounded, its tip anterior to tip of lower jaw; maxilla and mandibular teeth conical, uniserial; anterior nostril with short membranous tube, below snout margin; posterior nostril rounded, anterior to eye; posterior end of mouth posterior to vertical through middle of eye; cephalic sensory pores and lateral line developed; anus slightly anterior to middle of body; dorsal, anal, pectoral, and caudal fins present (dorsal-, anal-, and caudal-fin membranes fused); and dorsal fin origin slightly posterior to ventral through pectoral-fin base. A neighbor joining tree based on mtDNA cytochrome c oxidase subunit I (COI) gene sequences placed the specimen within a clade of C. maldivensis, based on previously published sequences, thereby supporting its conspecificity with C. maldivensis. The specimen was tentatively determined as a metamorphic larva, based on the following features: 153.7 mm TL, head length 12.7% of TL, and body opaque, with melanophores around the midline. An Indo-West Pacific species, C. maldivensis has previously been recorded from Tanzania to the Philippines, Wallis and Futuna Islands, and Australia, the present specimen therefore representing the first Japanese record and northernmost record of the species. The new standard Japanese name “Nan’you-okianago” is proposed for the species.

著者

出羽 優凪 伊東 正英 本村 浩之

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.22-008, (Released:2022-06-24)

参考文献数

22

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A single specimen [411.5 mm total length (TL)] of the Short-tail Brown Moray Gymnothorax pseudoprolatus Smith, Hibino and Ho, 2018 was collected at a depth of 27 m off Kasasa, Minami-satsuma, Kagoshima Prefecture, Japan. The specimen possessed the following characters: 75 pre-anal vertebrae; 175 total vertebrae; maxillary teeth biserial anteriorly and uniserial posteriorly; dentary teeth uniserial; 6 mandibular pores; head length (HL) 11.1% of TL; pre-dorsal length 8.6% of TL; body depth at gill opening 4.1% of TL; body uniformly brown; and lips whitish. Although G. pseudoprolatus is most similar to Gymnothorax prolatus Sasaki and Amaoka, 1991, it differs from the latter in having a longer pre-anal region (pre-anal length 50.0–53.6% of TL vs. 48–51% in G. prolatus), shorter snout (snout length 17.8–20.7% of HL vs. 20.0–23.8%), 6 mandibular pores (vs. 7), 75–78 pre-anal vertebrae (vs. 79–83), and 169–175 total vertebrae (vs. 182–187). In addition, analysis of the mitochondrial cytochrome oxidase I (COI) gene of both species showed them to be separated by 3.2–3.8% average sequence divergence. Gymnothorax pseudoprolatus has been previously known only from the holotype from Taiwan. Therefore the Kagoshima specimen represents the first record from Japanese waters and the northernmost record for the species. The new standard Japanese name “Chairo-utsubo” is proposed for the species.

著者

Tyson R. Roberts

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.33, no.2, pp.95-109, 1986-08-15 (Released:2010-06-28)

参考文献数

24

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ビルマとタイには14種のトゲウナギ科魚類が生息している.8種はMacrognathus属に, 6種はMastacembelus属に分類される.前者のうち2種はタイから発見された新種である.Mastacembelus dayiはビルマのみから知られており, M. alboguttatusに近縁である.タイとマレーシア西部に分布するMastacembelus favusは近縁のM. armatusから明瞭に識別できる.

著者

出羽 優凪 寺井 俊二 本村 浩之

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.21-020, (Released:2021-09-17)

参考文献数

15

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The triplefin genus Ceratobregma Holleman, 1987 includes two valid species, the Spotted Spiny-eye Triplefin C. acanthops (Whitley, 1964) and Helen’s Triplefin C. helenae Holleman, 1987. Both are characterized by the first dorsal fin having 3 spines, the anal fin 2 spines, and the pelvic fin with one spine and 2 rays, in addition to discontinuous lateral lines (upper series of tubular pored scales and lower series of notched scales), well developed lateral ethmoids, 3 or 4 spines on the anterior margin of the orbit in males, and a scaleless opercle and pectoral-fin base. Ceratobregma acanthops is known only from the Coral Sea, whereas C. helenae is widely distributed in the eastern Indian and western Pacific oceans. A single specimen (KAUM–I. 146836, 24.3 mm standard length) of C. helenae collected from Kume-jima Island, Okinawa Islands, Ryukyu Archipelago, Japan in October 2020 possessed the following characters: first spine of 1st dorsal-fin shorter than that of 2nd dorsal-fin; caudal peduncle narrow; sides of body with orange vertical bands; and 2nd dorsal fin with a basal series of orange spots. Previous records of the species from Japan include a single specimen (BPBM 8723, 29.6 mm standard length) collected from Taketomi-jima Island, Yaeyama Islands in 1968, and underwater photographs (as Ceratobregma sp.) taken at Irabu-jima and Miyako-jima Islands, Miyako Islands, in 2002 and 2004, respectively. The two Japanese specimens were examined, that from Kume-jima Island (described in detail) representing the northenmost record for the species. The new standard Japanese name “Mikan-hebigimpo” is proposed for C. helenae on the basis of the Kume-jima specimen, “Mikan-hebigimpo-zoku” serving for the genus Ceratobregma.

著者

永江 栞奈 高橋 弘明 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.21-007, (Released:2021-07-30)

参考文献数

23

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Mating behavior and early development of Cobitis sp. (BIWAE type D, TosaShima-dojo) were observed in the laboratory by inducing spawning of females with human chorionic gonadotropin (HCG). Subsequently, laboratory bred individuals were compared with spawned eggs and larvae obtained from the field. Mature adults, naturally spawned eggs, and larvae were collected from a river in eastern Kochi Prefecture, Shikoku Island, Japan, and a natural spawning ground adjacent to the river. Mating behavior was observed 15 times at night, and distinguished into four stages: phase 1, tracking; phase 2, approaching; phase 3, amplexus; and phase 4, spawning. Egg diameters after water absorption were 2.1–2.3 mm, the spherical, demersal eggs having a light-yellow yolk, no oil droplets, and slight viscosity. Newly hatched larvae [3.3–4.9 mm in total length (TL)] had 46 (32 + 14) myomeres, two pairs of outer gill filaments on the cheek, and melanophores on the head. Notochord flexion started at 6.0–7.2 mm TL (wild individuals at 6.0–6.3 mm TL) and was completed at 8.8 mm TL (6.6 mm TL). The formation of membranous fins and full fin-ray complements were attained in the fin order pectoral, caudal, dorsal, anal, and pelvic, and caudal, dorsal, anal, pectoral, and pelvic, respectively. Some individuals (7.0–8.0 mm TL at the flexion stage) had free neuromasts, each with a short cupula, laterally on the caudal region. In addition, following the postflexion stage, some morphological differences between artificially bred and wild individuals were observed but could not be quantified due to the small sample size.

著者

村﨑 謙太 甲斐 嘉晃 遠藤 広光 福井 篤

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.20-044, (Released:2021-05-10)

参考文献数

23

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Snailfishes (Cottoidei: Liparidae) are a large, morphologically diverse group of marine fishes, comprising about 32 genera with over 430 species worldwide. Among them, Osteodiscus Stein, 1978 is primarily distinguished from other genera in having a unique skeletal pelvic disk covered only by thin skin. Three species of the genus are currently known: Osteodiscus cascadiae Stein, 1978 from the eastern North Pacific; Osteodiscus andriashevi Pitruk and Fedorov, 1990 from southern Sea of Okhotsk; and Osteodiscus rhepostomias Stein, 2012 from southeast of New Zealand. During a taxonomic study of snailfishes, a single female specimen of Osteodiscus (150.3 mm in standard length) collected off Iwate in a depth of 1,997–2,108 m, was discovered in the fish collection of the National Museum of Nature and Science, Japan (NSMT). The specimen, characterized by 60 vertebrae (total), 54 dorsal- and 49 anal-fin rays, a horizontal mouth, simple blunt teeth on both jaws, some teeth with lateral cusps on the tip, an unnotched pectoral fin, and the presence of epipleural ribs and a reduced epural, was identified as O. andriashevi, previously known only from the holotype and three paratypes. The present specimen represents the first record of Osteodiscus from Japanese waters and the southernmost record of O. andriashevi. The new standard Japanese names “Hariban-kusauo-zoku” and “Choja-hariban-kusauo” are proposed for the genus and species, respectively. Based on the present specimen, the species diagnosis was partly revised.