著者
澤志 泰正 西田 睦
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.41, no.3, pp.253-260, 1994-11-21 (Released:2010-06-28)
参考文献数
14

現在の唯一の生息地である奄美大島において, リュウキュウアユは不連続な東西2地域 (住用・伊須湾域と焼内湾域) に分布する.この両地域の集団がどの程度独立であるかを明らかにするため, 生態学的側面および遺伝学的側面の両面から検討を試みた.まず, 遡上期における稚魚の分布を全島的に調査したところ, 東西2地域では従来通り本亜種の生息が確認できたが, それらを隔てる南部や北部地域の河川では本亜種は全く出現せず, 沿岸海域を通じての東西間の仔稚魚の移動の証拠は得られなかった.次に, 両地域の集団から得た標本にっいて電気泳動分析を行ったところ, 調べた28遺伝子座のうち多型的な2遺伝子座で, 遺伝子頻度の顕著な差異 (それぞれp<0.001) が認められた.以上の結果は, 東西両集団は, 相互の間でほとんど交流のない, 相対的に独立したものであることを示唆する.本亜種の保護を考える際には, こうした奄美大島における遺伝的多様性を慎重に考慮することが重要であると考えられた.
著者
岸野 底 四宮 明彦 寿 浩義
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.55, no.1, pp.1-8, 2008-05-15 (Released:2012-07-13)
参考文献数
28
被引用文献数
3

Fasting Ryukyu-ayu (Plecoglossus altivelis ryukyuensis) larvae (newlyhatched, 15-20 day old and 50 day old individuals) subjected to ranges of experimental water temperature and salinity [15-21°C (2 or 3 steps) and 0-30 psu (3 or 4 steps), respectively] showed greatest survival rates in water temperatures of 15-18°C and salinity of 5-15 psu. Such water temperature and salinity ranges paralleled those of brackish water in the Yakugachi River during the early life stages of Ryukyuayu, and supported a field investigation which indicated that Ryukyuayu larvae occurred mainly in brackish water. The experimental result is probably illustrates the limits of osmoregulatory adjustment in larvae of this species.
著者
近藤 卓哉 阪田 和弘 竹下 直彦 中園 明信 木村 清朗
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.46, no.2, pp.121-125, 1999-11-30 (Released:2010-06-28)
参考文献数
16

Iwana-charr, Salvelinus leucomaenis is not indigenous to Kyushu Island western Japan. In 1971, this species was transplanted to a commercial hatchery by the Haki River (32°32'N, 130°57'E), a tributary of the upper reaches of the Kuma River System. Some of the charr individuals escaped from the hatchery's holding pond and came into the stream. Fifty-one were collected in the lower reaches near the hatchery but none in the upper reaches during 1994-1996. The collected sample consisted of individuals belonging to plural age classes. In addition, we observed some spawning activities of the charr in November every year during 1994-1997 and found some eggs in the redd. Our findings suggest that reproduction of the charr occurs in some tributaries of the upper reaches of the Kuma River and their distribution is expanding downstream. They also suggest that dams without fishways prevent the charr from migrating upstream.
著者
仲谷 一宏
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.29, no.4, pp.469-473, 1983-03-10 (Released:2010-06-28)
参考文献数
6

タイワンザメProscyllium habereriは台湾・高雄から得られた成体雄1尾の標本に基づいてHilgendorf (1904) により記載された.その後, Tanaka (1912) は日本からヒョウザメCalliscyllium vemstumを記載したが, この両種の取り扱いは研究者により様々である.今回, タイワンザメの完模式標本 (ZMB16201) を調査し, ヒョウザメの原記載と直接比較する機会を得たが, 現在のところ, 両者のもっとも大きな差異は斑紋であった.しかし, タイワンザメの模式模本の体色, 斑紋は消失しつつあり, さらに原記載が簡単で図もないため, ここに詳細な完模式標本の再記載を行った。なお, タイワンザメととヨウザメの分類学的関係については将来の研究が必要である.
著者
藤本 泰文 福田 亘佑
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.70, no.1, pp.111-118, 2023-04-25 (Released:2023-04-30)
参考文献数
38

Although overfishing has been recognized as a major factor threatening the existence of rare freshwater fishes, no case studies exist on the impact of collection pressure by fish enthusiasts and traders. In 2021, a habitat of reintroduced Acheilognathus typus, a species rarely seen the previous year, was visited every day by such enthusiasts. A monitoring survey indicated subsequently that the mean number of captured A. typus had decreased from 25.0 individuals/day in July 2021 to 1.6 individuals/day in October, the October 2021 figure being about one-tenth of that for September-October 2020. In addition, the standard length of A. typus in 2021 (56.8–59.5 mm) was greater than in 2020 (47.2 mm), possibly due to a thinning effect caused by the reduced fish numbers. During the period surveyed, some 50 to 100 fish enthusiasts and traders visited the habitat, apparently collecting thousands of A. typus by fishing or in bait traps. Such collecting pressure has clearly driven the reintroduced population of these rare fish to significantly low levels within a short period.
著者
佐藤 光雄 高橋 正嗣
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.15, no.1, pp.1-6, 1968-11-29 (Released:2010-06-28)
参考文献数
9

1. ひげを先端から約1/2のところで切断すると, 18時間後には傷口は表皮によって完全におおわれ, 中心血管の切り口も血塊栓によってふさがれてしまう。2. 切断後5日目になると, 切断端付近の表皮下間隙の大半を領していた血塊と, 上記の血塊栓は次第に吸収され, これらの部分は結合組織由来の細胞によって占められる.この細胞群が再生芽とみなされる。3. 平滑筋層の再生は主として再生芽細胞の平滑筋細胞への分化によって起り, これに既存の平滑筋細胞の分裂が一部あずかっている.4. 中心血管の再生は, 既存の内皮細胞の分裂増加によらず, 再生芽細胞の内皮細胞への分化にもとづくものと考えられるが, 今後なお検討の要がある.5. 再生部の表皮に終末球が出現する時期は切断の10日目以後であり, 25日目には再生部の組織構造が正常部のそれとほぼ等しくなる.再生部の伸長速度は1日あたり平均0.06mmであった.6. 本種では, 再生部付近の表皮はもちろん, 結合組織にも分裂像が明らかに認められる.
著者
谷津 明彦 安田 富士郎 多紀 保彦
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.25, no.1, pp.40-50, 1978-06-26 (Released:2010-06-28)
参考文献数
15

タウエガジ科の1新種ベニツケギンポDictyosomarubrimaculataを記載した。本種は, 従来, 同属のダイナンギンポD.burgeriと混同して扱われていたため, D.burgeriの再記載も行なった。両種は側線形態, 不対鰭条数, 体色等の相違により区別される。さらに, D.burgeriに地理的変異の2型が認められたが, より詳細な分布の検討が必要であると考えられたので, 今回の報告では, 本州中部太平洋岸から得られたfbrm aと日本海及びその周辺水域から得られたfbrm bとに暫定的に分けるにとどめた.D.rubrimaculataとD.burgeriの2型は, それぞれ同所的に分布しており, 千葉県小湊と神奈川県横須賀での水中観察の結果では, 両者は棲み分けを行なっていた。すなわち, D.rubrimaculataは所謂ガラモ場と呼ばれる潮下帯の一部に, 一方D.burgeriのform aは岩礁の潮間帯に主に見い出される.D.burgeriにおける脊椎骨数の増加, 腹鰭の退縮などの形態的特徴と上記の生活場所に関しての知見は, D.urgeriがより特化した種であることを示唆している.
著者
高村 健二
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.52, no.2, pp.107-114, 2005-11-25 (Released:2010-06-28)
参考文献数
17
被引用文献数
5

Black bass populations in Japan were examined for haplotypes of the mitochondrial DNA control region. A total of 16 haplotypes were found from specimens representing 47 Japanese populations and five in North America. Ten haplotypes were of largemouth bass, and three each of Florida bass and smallmouth bass. Three clades of largemouth bass haplotypes were identified by the maximum parsimony method, the major clade comprising seven haplotypes including those found in Iowa, Minnesota and Ontario (USA). It ispossible that the haplotypes of this clade in Japan originated from the introduction of fish from Minnesota and Pennsylvania in 1972. One of the remaining clades, comprising a single haplotype and found throughout Japan, may have originated from the introduction of cultured fish from California in 1925. All of the seven largemouth bass haplotypes found in Japan were found in Lake Yamanaka, such haplotype richness reflecting active stockings of largemouth bass from other Japanese freshwaters. Florida bass haplotypes were found only in Lake Biwa, indicating that the haplotypes could function as indicators of future invasion of black bass into other waters with the active transplantation of other commercially valuable fishes from the lake.
著者
平嶋 健太郎 立原 一憲
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.47, no.1, pp.29-41, 2000-05-25 (Released:2010-06-28)
参考文献数
28

Members of the genus Rhinogobius are widely distributed in Far East Asia, at least 11 species having been recognized in Japan. Of the six species recorded from Okinawa Island, two are land-locked (“aobara-yoshinobori” R. sp.BB and “kibara-yoshinobori” R. sp.YB) and the remainder amphidromous. Embryonic development and morphological changes in the two land-locked species are described from artifically-reared eggs, larvae and juveniles. Survival and growth of the two species were compared under different salinities (0-35%0) dur-ing a 21-day period following hatching. Although egg diameters of both species were almost the same (“aobara-yoshinobori”; 4.3±0.1 mm, “kibara-yoshinobori”; 4.3±0.2 mm), newly-hatched larval morphology, and larval and juvenile salinity tolerance clearly differed. Newly-hatched larvae of “aobara-yoshinobori” had a flexed notochord and caudal fin rays already developed. The yolk was completely consumed 3 days after hatching. By comparison, “kibara-yoshinobori” hatched at an ealier developmental stage, having a straight notochord. The yolk disappeared 7 days after hatching. Larvae and juveniles of “aobara-yoshinobori” were less toler-ant in high salinity than those of “kibara-yoshinobori”. The results suggested that the two land-locked gobies have become adapted to a wholly fluvial life cycle, through somewhat different strategies.
著者
武田 恵三
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.4, pp.198-202, 1975-03-15 (Released:2011-07-04)
参考文献数
11
被引用文献数
1

In Onaga-tani (Fig.1.B) and Sutani River (Fig.1.C) in the upper reaches of Ane River and Echi River of Lake Biwa water system, the author collected specimens which seem to be the char, Salvelinus leucomaenis having zigzag marks, instead of parr-marks, on their body side.Since such specimens are not known, the author describes their form (Table 1), localities, and habitats.Specimens with atypical color patterns may be variation of Salvelinus leucomaenis (Pallas), and not hybrids between other salmonids and the char.Japanese name “6 nagaremon -iwana” is proposed for these variants.
著者
Waikhom Vishwanath Chungkham Sarojnalini
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.35, no.2, pp.124-126, 1988-09-20 (Released:2010-06-28)
参考文献数
3

インドのマニプル川から得られたコイ科の1新種Garra manipurensisを記載した.本種はダージリン・ヒマラヤ産の同属のG. annandalei Hora隔が広いこと, 側線上方鱗数が多いこと, 肛門の位置が後であることなどの点で異なる.また, ブラマプトラ川流域やアッサム・ヒマラヤに産するG. lissorhynchus (McClelland) とは背鰭および尾鰭に斑紋を欠くこと, 腹部に鱗があることなどの点で異なる.
著者
福冨 則夫 中村 智幸 土居 隆秀 武田 維倫 尾田 紀夫
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.49, no.1, pp.53-58, 2002-05-24 (Released:2010-06-28)
参考文献数
16

Twenty-one specimens of the Pacific lamprey, Entosphenus tridentatus, were collected from the Hoki (8 specimens), Yusaka (11 specimens) and Arakawa Rivers (1 specimen), all tributaries of the Naka River, and the mainstream of the Naka River (1 specimen), Tochigi Prefecture, central Japan, between August 1999 and April 2001. Seven spawning redds, possibly constructed by Entosphenus tridentatus, were found in the Yusaka River on May 2 and 11, 2000, eggs being observed in one of them. Two specimens, collected from the Yusaka River and reared in an aquarium with a gravel substrate, subsequently spawned about 1000 eggs being observed in the redd. Forty-one of the eggs were reared at 15°C in an electric incubator, hatching starting 13-17 days after spawning. The hatching percentage was 92.7%, the accumulative temperature to hatching being between 195 and 255°C.
著者
伴 和幸 髙見 宗広 冨山 晋一 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
vol.60, no.2, pp.117-121, 2013-11-05 (Released:2015-12-26)
参考文献数
10

Two chiasmodontid specimens (110.2–232.0 mm in standard length), collected off Shikoku, Japan, represent the first records of Kali colubrina Melo 2008 from Japanese waters, being distinguished from six congeneric species by the combination of a unique dentition pattern (two rows of recurved caniniform teeth on the premaxilla and dentary, not developed as fangs, 12–22 lateral and 5–9 mesial teeth on the premaxilla, 8–18 lateral and 5–10 mesial teeth on the dentary, mesial teeth larger than adjacent lateral teeth), 23–26 second dorsal-fin rays, 23–25 anal-fin rays and 39–41 vertebrae. The new Japanese name “Jaguchi-bouzugisu” is proposed for the species.
著者
樋口 文夫 渡辺 勝敏
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.52, no.1, pp.41-46, 2005-05-25 (Released:2010-06-28)
参考文献数
21
被引用文献数
4

The genetic population structure of Rhynchocypris lagowskii steindachneri in three river systems flowing through Yokohama and adjacent areas in southwestern Kanto, central Honshu, Japan, was investigated by examination of nucleotide sequences of the mitochondrial DNA (mtDNA) control region. Although R. lagowskii steindachneri is the only Rhynchocypris species native to the region, the establishment of R. oxycephalus jouyi, which was artificially introduced in the late 1980's, was confirmed in one of the river systems investigated. From the same river system, one of 27 specimens (4%) of R. lagowskii steindachneri was found to have a R. oxycephalus jouyi mtDNA type, implying some genetic disturbance within the former population. Although the R. lagowskii steindachneri populations investigated, distributed within a 40-km geographic range, appeared to belong toa single phylogeographic group, significant differences in haplotype frequencies and diversity levels were found, probably being the result of genetic drift following recent artificial fragmentation and habitat reduction.
著者
福井 謙太郎 藤井 亮吏 田原 大輔 早川 洋一 古屋 康則
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.54, no.2, pp.173-186, 2007-11-26 (Released:2011-12-02)
参考文献数
39
被引用文献数
1

Gonadal development and serum profiles of sex steroids in reproductive KAJIKA, Cottus sp.SE (small egg type), were monitored over a 12-month period. The female reproductive cycle was divided into the following 5 periods based on oocyte development: recovery period (May to August), cortical alveoli formation period (September), vitellogenic period (October to December), reproductive period (January and February) and spent period (March and April). Based on ovarian histological observations, females may spawn 2 or 3 times in one reproductive period. Serum levels of estradiol-17β increased during the vitellogenic period, indicating regulation of the vitellogenetic progress. Serum 17, 20β-dihydroxy-4-pregnen-3-one in females exhibited high levels only during the reproductive period, suggesting a role in inducing final oocyte maturation. The male reproductive cycle was divided into the following 5 periods based on testicular histological observations: resting period (June to August), spermatogonial proliferation period (September), spermatogenic period (October and November), reproductive period (December to February) and spent period (March to May). Parasperm formation, which is known in some cottidae species, was noted, occurring in the sperm ducts during the spermatogenic period, but only in the main testicular lobes during the reproductive period. Serum 11-ketotestosterone levels in males increase of continually during the spermatogenic period, suggesting a role regulation of spermatogenesis in this species.
著者
千田 哲資 陳 新民
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.22, no.2, pp.68-76, 1975-12-15 (Released:2010-06-28)
参考文献数
32

インド・太平洋海区からは5種のヒメダイ属が知られており, そのうち側線鱗数が50前後のものはPristipomoides typus Bleeker1種のみとされていた.しかるに, 南支那海およびアンダマン海のヒメダイ属魚類のうち側線鱗数48~52の魚には別種と見做すべき2型があり, そのひとつはP.typusであり, 他はBleeker (1876~1877) 以来その異名同種とされてきたDay (1870) のMesoprion multidensに該当することが判った.後者を前者より区別する主要点は, 吻および頬部に黄色線がある, 頭頂部の虫食い状斑紋が横に走る (前者では縦), 眼下骨幅が大きい, 上下両顎の犬歯が大きい, 尾鰭上葉の延長がより若いうちにみられなくなる, 第一血管棘の横幅は基部より約3/5の点で急に狭くなる (前者では基部から尖端に向かって一様に横幅を減ずる), 第一尾椎骨の血道弓門は卵形である (前者では細長い三角形), などである.目本人研究者 (赤崎, 1965;篠原, 1966;久新・他, 1973) によりナガサキフエダイの和名で記載されている魚はP.multidensであり, 新たにP.typusの和名としてバラヒメダイを提唱する.目本では屡々ナガサキフエダイの学名としてP.arglyrogrammicus (Valenciennes) が採用されているが, 後者の模式標本の側線鱗数は, 58 (Sauvage, 1891) もしくは61 (パリ国立科学博物館Dr.Rouxによる) であり, 両者が同種である可能性はない.Schlegel (1842) が目本より報告したDiacope sparusが表記両種のいずれを指すかは明らかでない.