著者
明仁 藍澤 正宏 池田 祐二 岸田 宗範 林 公義 中山 耕至 中坊 徹次
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
pp.18-044, (Released:2019-04-05)
参考文献数
32

Hybrids of Rhinogobius biwaensis and Rhinogobius sp. BF were identified in the ponds of Sento Imperial Palace, Kyoto City, Japan, from microsatellite and mitochondrial DNA markers. Mitochondrial DNA analysis indicated that five of seven Rhinogobius specimens had R. biwaensis haplotypes, the remaining specimens having those of Rhinogobius sp. BF. In DAPC and STRUCTURE analyses based on microsatellite data, all specimens examined showed intermediate status between R. biwaensis and Rhinogobius sp. BF, the two species being considered to have formed a hybrid swarm in the ponds because genetically pure individuals of either were not found. This is the first report of recent hybridization under field conditions in Rhinogobius fishes from Japan, confirmed by nuclear and mitochondrial DNA data. Hybrid Rhinogobius specimens from the ponds had 5–17 predorsal scales, an intermediate range between those of non-hybrid R. biwaensis (0–6) and Rhinogobius sp. BF (11–20). However, in appearance they were more similar to R. biwaensis than Rhinogobius sp. BF, having bluish-white distal coloring anteriorly on the first and second dorsal fins, a reduced reddish longitudinal band on the anal fin, and lacking yellowish dorsal and posterior margins on the caudal fin. However, they differed from R. biwaensis in having a narrower white posterior caudal fin margin. Further morphological differentiation of the hybrid specimens was not apparent.
著者
竹花 佑介 北川 忠生
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.57, no.1, pp.76-79, 2010 (Released:2014-03-05)
参考文献数
18
被引用文献数
1
著者
小山 直人 北川 忠生
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.56, no.2, pp.153-157, 2009 (Released:2014-03-05)
参考文献数
12
被引用文献数
1

In order to examine genetic introgression from the orange-red type commercial strain of Oryzias latipes (himedaka) to wild medaka populations, a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome b gene was conducted for 45 populations from the Yamato River system, Nara Prefecture and two fish farm populations from special product grounds of himedaka (Yamatokoriyama and Yatomi Cities). Orange-red type fish only were collected from three sites, and a mixture of wild and orange-red types from sympatric populations at four other sites in theYamato R. system. Most orange-red type specimens had the B27 mitotype, being identical with that of the typical orange-red type Hd-rR strain. Although most of the wild type fish individuals had mitotype B1a, inferred as one of the native mitotypes in the Yamato R., four from three sites had mitotype B27, implying genetic introgression from himedaka to wild medaka populations.
著者
馬渕 浩司 瀬能 宏 武島 弘彦 中井 克樹 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.57, no.1, pp.1-12, 2010 (Released:2014-03-05)
参考文献数
22

A recent mitochondrial (mt) DNA survey revealed that the native Japanese population of the common carp has been endangered by the introduction of non-native domesticated strains: more than half of the haplotypes detected so far in Japanese waters originated from Eurasian strains. In expectation that Lake Biwa, the largest freshwater body in Japan, contains a relatively pure native population, we conducted a survey of mtDNA haplotypes in the lake, collecting 856 common carp from 40 localities in the lake. Of these, 606 specimens were caught by various nets (gill net, set net, net trap, etc.) used at depths from 1 to 5 m, 148 specimens were caught by a trawl net used at depths from 30-70 m, and 102 specimens that had washed ashore during mass mortality caused by Koi herpes virus (KHV) in 2004 were collected by hand. For each of the specimens, the mitochondria- encoded cytochrome b gene was genotyped (Japanese native or non-native haplotypes) by PCR using allele-specific primers. Analysis of haplotype frequencies showed that the native Japanese haplotype was significantly more frequent in deep off-shore waters and waters along the steep northern coast of the North Basin (about 80% on average), than in shallow coastal waters in the South Basin and waters along the eastern coast of the North Basin (less than 50% on average). These results indicate that the deep waters of the lake may contain a relatively pure native population that is of prime importance for conserving the native Japanese common carp. Among the results, it is notable that more than 90% of the KHV-killed specimens had native Japanese haplotypes.
著者
中島 淳 橋口 康之 杉尾 哲 東 貴志 越迫 由香里 田口 智也
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
pp.18-024, (Released:2019-02-06)
参考文献数
42

Two voucher specimens of the spined loach, Cobitis matsubarae Okada and Ikeda, 1939, collected from the Shonai River, a branch river of the Oyodo River system, southern Kyushu, Japan, represent the first reliable record of that species from the Oyodo River system. Morphological features of the male lamina circularis, prepelvic myotome number, maxillary barbel length, snout length, body pigmentation patterns, and genetic characteristics of mtDNA cytb sequences were in close agreement with characters those of C. matsubarae. Together with C. sakahoko, C. matsubarae, is considered to be distributed naturally in the Oyodo River system.
著者
明仁親王 目黒 勝介
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.3, pp.127-142, 1975-12-29 (Released:2010-06-28)
参考文献数
28

フタゴハゼGlossogobius giuris (Hamilton) と見なされていたウロハゼ属の1型は新種と認められたのでG.aureus (新称: コンジキハゼ) として記載した.本種の最も重要な特徴は孔器の配列にある.ウロハゼ属の他の種と比較し, その特徴を明らかにした.
著者
宗原 弘幸 高野 和則 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.37, no.4, pp.391-394, 1991-02-28 (Released:2010-06-28)
参考文献数
13

交尾型カジカ, イソバテングBlepsias cirrhosusの配偶子がいつ, どこで会合し受精開始するかを明らかにした.排卵した雌の卵巣腔から卵と卵巣腔液を取り出し, 一部の卵を海水または卵巣腔液に浸し, 24時間後にそれぞれの胚発生状態を観察した.その結果, 海水中の卵のほとんどは胚発生を開始していたが, 卵巣腔液中の卵は全く発生しなかった.しかし, これらの未変化の卵を海水に移すと, その多くが胚発生を開始した.また, 海水に浸す前の卵を光顕観察した結果, 多数の精子が卵門管内に侵入しているものの, 卵細胞質内への貫入は認められず.卵も第二減数分裂の中期にとどまっていることが確認された.以上の結果から, 本種では体内で両配偶子の会合は終えているが, 受精は産卵後海水中で開始することが明らかとなった.
著者
松本 清二 岩田 勝哉
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.44, no.1, pp.35-41, 1997-05-26 (Released:2010-06-28)
参考文献数
13
被引用文献数
1

Paternal egg guarding and mouthbrooding of larvae and juveniles were observed in the swamp-eel, Monopterus albus. In aquaria, the male guarded and cared for eggs in the bubble nest floating inside a plastic tube (5 cm in dia-meter, 50 cm in length). It was suggested that spawning and fertilization occurred outside the nest tube, and that the male carried the fertilized eggs (ca. 4 mm in diameter) in his mouth and inserted them into the bubble mass. Until the hatching of larvae (7-8 days after spawning), the male frequently added fresh bubbles into the bubble mass. As soon as the larvae (18-21 mm in TL) hatched and emerged from the bubble nest, the male sucked them into his mouth. Fifty juveniles (32-37 mm in TL) and two yolk-sac larvae (22 mm in TL) were released from the mouth of a male collected from a natural habitat. Those juveniles were retrieved by the male, some of them voluntarily returning to the male's mouth. The mouthbrooding male frequently performed pumping behavior (i.e., inflating and deflating the buccopharyngeal cavity), thereby acquiring to take fresh air. Eggs removed from the bubble nest successfully hatched only when directly exposed to aeration. In addition, only about 40% of the hatched larvae survived more than 10 days when they were kept in well-aerated water without the male parent. These suggest that both the bubble nest and mouthbrooding are indispensable for successful development and survival of eggs and larvae in this species, which inhabits swamps and paddy fields.
著者
谷 良夫 林 亮太朗 髙田 一翔 大路 紘裕 入江 祐樹 今村 拓未 早川 祐 向井 貴彦
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
pp.18-002, (Released:2019-03-29)
参考文献数
24

Nuclear DNA (nDNA) markers were developed to distinguish between the closely related brackish water gobies Tridentiger brevispinis and T. obscurus. Although genetic differentiation of the two species has already been demonstrated by allozyme analysis in previous studies, the nucleotide sequences of mitochondrial DNA (mtDNA) haplotypes were similar and often shared by introgressive hybridization, obscuring the identification of the two species by mtDNA markers. In this study, one mtDNA gene [cytochrome b (cytb)] and four nuclear DNA gene regions [G protein-coupled receptor 85 (gpr85), ryanodine receptor 3 (ryr3), recombination activating protein 1 (rag1) and zic family member 1 (zic1)] were sequenced in 11 to 17 individuals, respectively, of T. brevispinis and T. obscurus, collected from the Mukogawa River, Hyogo Prefecture, Japan. The results for the mtDNA cytb region matched those of previous studies, the nucleotide sequences being very similar, with haplotypes shared among species. On the other hand, two (gpr85 and ryr3) of the four nDNA regions clearly differed between the two species, PCR-RFLP conducted on the former also showing specifically-different electrophoretic patterns. In order to confirm that nDNA PCR-RFLP could distinguish between the two species in other populations, additional samples of both from the Shonai River, Aichi Prefecture were subjected to and identified by the above method. In addition, eight individuals of putative F1 hybrid identified by allozyme analysis (three diagnostic loci) were also investigated. Although six of the eight putative hybrids included heterozygotes at both of the two nDNA PCR-RFLP loci, two individuals were characterized by a heterozygotic pattern at one locus, homozygotic at the other, both individuals possibly being F2 or backcross progeny, although initially misidentified as F1. The results indicated that nDNA markers may be helpful in distinguishing closely related Tridentiger species, which cannot be identified by mtDNA markers.
著者
田和 篤史 田原 義太慶 日比野 友亮
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
pp.17-050, (Released:2018-03-30)
参考文献数
24

Snake eels in the genus Myrichthys, characterized by molariform teeth, moderate to very elongate body, short snout, dorsal fin origin before gill openings, short pectoral fin, anterior nostrils tubular and elongate, posterior nostrils opening into mouth, and spotted and/or striped coloration, include 10 valid species and are commonly found along most tropical shores worldwide. Two species, Myrichthys colubrinus (Boddaert, 1781) [striped coloration] and Myrichthys maculosus (Cuvier, 1816) [spotted coloration], having been previously recorded from Japan, Myrichthys paleracio McCosker and Allen, 2012 is described here from two specimens found in the stomach contents of a sea snake Laticauda laticaudata (Linnaeus, 1758) from Iriomote Island, Okinawa Prefecture, Japan, being the first speciemen-supported record of the species from Japan and the northernmost record of distribution. Myrichthys paleracio most closely resembles M. colubrinus in having striped body coloration, but differs in having 183 total vertebrae (vs. 193–202) and more than 50 irregularly patterned brown stripes (vs. 25–35 arranged in a regular pattern). The absence of an ethmoid pore on the head in one specimen was considered to be a malformation. A new standard Japanese name “Madara-shima-umihebi” proposed for the species. An underwater photograph of a snake eel from Yakushima Island, Kagoshima Prefecture, Japan, was identified as M. paleracio.
著者
渡辺 勝敏 一柳 英隆 阿部 司 岩田 明久
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.61, no.2, pp.69-83, 2014-11-05 (Released:2016-12-25)
参考文献数
27
被引用文献数
1

The population of the botiid Parabotia curtus in the Katsura River, Lake BiwaYodo River system, Kameoka, Kyoto Prefecture, Japan, the only one recorded in the Kinki region since the year 2000, was subjected to a population viability analysis (PVA) based on demographic data between 2006 and 2013 (8 years). Count-based and age-structured models with several conditions for density-dependence, carrying capacity, migration rate, and bias in population estimation (48 settings in total) were used for calculating the quasi-extinction probability within 50 years (extinction threshold <10 individuals), using computer simulations. The estimated population for the 8 year period fluctuated from 200 to 2,300 individuals (average ca. 935, with a coefficient of variation of 66%). PVA demonstrated a significant extinction risk for this population (23–82% extinction in 45 of 48 settings). Although further population monitoring is necessary for a more precise evaluation, we conclude that this population faces a real extinction risk. Sensitivity analysis suggested several requirements for effectively enhancing population viability, i.e., restraining large biotic and abiotic environmental perturbations to avoid extreme depression of the recruitment of young, enhancing winter survival, and promoting upstream migration into the spawning site.
著者
篠原 現人 尼岡 邦夫
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.40, no.4, pp.487-490, 1994-02-15 (Released:2010-06-28)
参考文献数
11

北海道室蘭沖から得られ, 完模式標本以外に採集例のないヤセアイナメStellistius katsukii Jordan et Tanaka, 1927と同海域で普通に採集されるホッケPleurogrammus azonus Jordan et Metz, 1913との関係について主に外部形態に基づき調査した.両種の完模式標本と日本各地から得た23個体のホッケの標本を比較したところ, 両者に差異は認められなかった.従って, ヤセアイナメはホッケのシノニムであり, ヤセアイナメ1種のみを含むヤセアイナメ属Stellistiusもホッケ属Pleurogmmmusのシノニムである.また, 背鰭第1鰭条が長く, 後続のものとほとんど同じであるというヤセアイナメ属の特徴は模式標本の再調査では認あられず, Jordan and Tanaka (1927) の観察が誤りであったと判断された.
著者
稲田 伊史 J.A.F. Garrick
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.25, no.4, pp.235-243, 1979-02-15 (Released:2010-06-28)
参考文献数
23

Rhinochimaera pacifica previously known only from Japan and Peru is reported and described from 23 New Zealand specimens taken on the Chatham Rise, Challenger Plateau and east of Stewart Island in depths of 750-1110 m. Comparison with R.atlantica, the other nominal species, shows that R.pacifica differs only in its higher number of denticulations on the upper caudal margin of males (34-69 in New Zealand and Japanese specimens, 25-30 in R.atlantica).
著者
明仁 藍澤 正宏 池田 祐二 岸田 宗範 林 公義 中山 耕至 中坊 徹次
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
2019

<p>Hybrids of <i>Rhinogobius biwaensis</i> and <i>Rhinogobius</i> sp. BF were identified in the ponds of Sento Imperial Palace, Kyoto City, Japan, from microsatellite and mitochondrial DNA markers. Mitochondrial DNA analysis indicated that five of seven <i>Rhinogobius</i> specimens had <i>R. biwaensis</i> haplotypes, the remaining specimens having those of <i>Rhinogobius</i> sp. BF. In DAPC and STRUCTURE analyses based on microsatellite data, all specimens examined showed intermediate status between <i>R. biwaensis</i> and <i>Rhinogobius</i> sp. BF, the two species being considered to have formed a hybrid swarm in the ponds because genetically pure individuals of either were not found. This is the first report of recent hybridization under field conditions in <i>Rhinogobius</i> fishes from Japan, confirmed by nuclear and mitochondrial DNA data. Hybrid <i>Rhinogobius</i> specimens from the ponds had 5–17 predorsal scales, an intermediate range between those of non-hybrid <i>R. biwaensis</i> (0–6) and <i>Rhinogobius</i> sp. BF (11–20). However, in appearance they were more similar to <i>R. biwaensis</i> than <i>Rhinogobius</i> sp. BF, having bluish-white distal coloring anteriorly on the first and second dorsal fins, a reduced reddish longitudinal band on the anal fin, and lacking yellowish dorsal and posterior margins on the caudal fin. However, they differed from <i>R. biwaensis</i> in having a narrower white posterior caudal fin margin. Further morphological differentiation of the hybrid specimens was not apparent.</p>
著者
髙橋 夢加 岡田 誠 笹木 大地 本村 浩之 木村 清志
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
pp.18-023, (Released:2018-09-19)
参考文献数
11

The carangid genus Decapterus Bleeker, 1851 is characterized by single finlets behind both the second dorsal and anal fins, no scutes along the anterior curved part of the lateral line, two low papillae on the shoulder girdle, and a well-developed adipose eyelid. Members of the genus are distributed in tropical to temperate areas of the Pacific, Indian and Atlantic oceans, and are commercially important food fishes. Four species (D. akaadsi Abe, 1958, D. kurroides Bleeker, 1855, D. smithvanizi Kimura, Katahira and Kuriiwa, 2013 and D. tabl Berry, 1968), characterized by a red caudal fin, are included in the red-fin Decapterus group. In 2016 and 2018, three specimens [216–304 mm in standard length (SL)] of D. kurroides, previously recorded from the Red Sea and east coast of Africa to the east coast of Australia and the Philippines, were collected from Kumano-nada, Pacific coast of Mie Prefecture, Japan. Additionally, a single specimen (191 mm SL) collected from Japanese waters in the East China Sea (west of Kyushu) in 2006 was also identified as D. kurroides. The specimens represent the first records of the species from Japanese waters, the Kumano-nada specimens being the northernmost record for the species. Decapterus kurroides is the most similar to D. akaadsi, but differs from the latter in the following characters: scutes more numerous on the straight part of the lateral line (30–32 vs. 26–29 in D. akaadsi), longer head (head length 29.9–33.0% SL vs. 26.7–30.1%) and longer snout-anus distance (55.8–60.4% SL vs. 51.2–54.6%) [measurements for both species modified from Kimura et al., (2013)]. Decapterus kurroides is also distinguishable from D. smithvanizi and D. tabl by having fewer cycloid scales on the curved part of the lateral line (45–52 vs. 54–62 in D. smithvanizi, 61–72 in D. tabl) and a deeper body (body depth 23.4–27.2% SL vs. 19.4–22.5%, 16.6–23.0%). A new standard Japanese name “Kitsune-akaaji” is proposed for D. kurroides.
著者
仲谷 一宏
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.40, no.1, pp.35-42, 1993-05-15 (Released:2010-06-28)
参考文献数
9

1992年3月8日午後, 愛媛県松山市堀江沖2.3km, 水深22メートルの海底でヘルメット式潜水器具を用いてタイラギ貝漁をしていた潜水夫が行方不明になった.この潜水漁を支援していた船の船長によると, 作業中の潜水夫から突然「上げてくれ」という救助を求める声を聞き, 20分程度かけてやっと引き上げたが, ズタズタに裂けた潜水服とヘルメットだけを回収したという.潜水夫は行方不明で, その後の捜索にもかかわらず, 結局発見できなかった.この事故直後に海上保安部などにより潜水服の調査が行われ, その結果サメによる事故とされた.しかし, その後は詳しい調査が行われず, サメ以外の説も出されるようになったため, 佐賀県太良町の潜水士宅に保管されていた潜水服の再調査を実施した.その結果, 潜水服は胸部から脇腹にかけての胴部右半分と右足が切断され, 肩や腕などに多くの咬み傷のあることが改めて確認された.ヘルメットを固定する金属性の肩当て部分には強い力で穿孔されたと思われる穴や細かな平行な曲線からなる傷跡があり, 通信用ケーブルやゴム部の切断面にも細かな平行のすじ状の模様があった.肩当て部分のゴムの深い傷から長さ約5mm, 幅約2.5mmの歯の破片が発見され, これには2個の鋸歯が残されていた.また, 肩当てや潜水服に残された咬み跡を調査して顎の幅を検討したところ, 40cmはあったと推定された.これらの証拠から, この潜水夫を襲ったのは歯の縁辺部に鋸歯をもっかなり大形のサメであったことが明白となった.これらの歯の破片の特徴, 潜水服などに残された傷跡, 顎の大きさなどに加え, 水温 (当時の付近の水温は水深20mで1L6℃) や四国近海での当時のサメ類の出現状況などを総合的に検討した結果, この潜水夫を襲ったのは全長5m前後のホホジロザメであると結論された.日本では以前からサメによる被害が新聞などで時々報道されているが, これらの記録は散逸し, 被害の実態を捕らえることが出来ない.従って, 日本のサメによる被害を調査したが, 公認されているものも含め現時点で10数件の被害例を見い出した.しかし, これらの日本の事例においては, 襲ったサメの種類調査など後の科学的調査がほとんどなされていないため, 日本で被害を与えているサメについては種名すら分かっていないのが現状である.将来のサメによる事故を防ぐ意味からも, まだ埋もれているサメ被害例を発見し, 分析してみる必要があろう.なお, 本研究で集められたサメによる被害にっいては国際サメ被害目録 (International Shark Attack File, 事務局はフロリダ自然史博物館) に載せておいた.
著者
渡辺 勝敏 前田 洋志
出版者
The Ichthyological Society of Japan
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
vol.41, no.4, pp.409-420, 1995-02-21 (Released:2010-06-28)
参考文献数
23

遺伝学的に別種であることが示されている日本産ギギ科魚類2種, Pseudobagrus aurantiacus (Temminck and Schlegel) (アリアケギバチ) とそのシノニムとして扱われてきたP. tokiensis Döderlein (ギバチ) について, 模式標本を含む多数の標本を基に両種を再記載し, 形態比較を行った.その結果, P. aurantiacusは, より高い背鰭, 胸鰭棘前縁を広く覆う顕著な鋸歯列, 外向きの1-3歯を伴うより高密度な同後縁鋸歯列, より幅広い上後頭骨突起, 上後頭骨突起と同程度の長さの大きな上神経骨, 幅広い擬鎖骨後方突起 (後端>20°), 外翼状骨から大きく離れた舌顎骨前縁より明瞭な若魚の体斑パターン, 等によってP. tokiensisから区別された.
著者
兼森 雄一 竹垣 毅 夏苅 豊
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.53, no.2, pp.133-141, 2006-11-25 (Released:2010-06-28)
参考文献数
45

The genetic population structure of the mudskipper Boleophthalmus pectinirostris was investigated based on nucleotide sequence data from the mitochondrial control region (472 bp) of 131 individuals collected from four localities in Ariake Bay, two in Yatsushiro Bay, Kyushu, Japan, one in Korea (Suncheon) and one in China (Zhe Jiang). A total of 53 composite haplotypes were observed from 49 permutation sites. The estimated haplotype tree and pairwise Fst showed genetic differentiation among the Suncheon, Zhe Jiang and Japanese populations. The structures of the haplotype tree and network, and low genetic diversity of the Japanese populations compared to that at Zhe Jiang suggested that a bottleneck effect had occurred in the former after being isolated from the continental population by rising sea levels (i. e., relictual species). Based on the number of unique haplotypes in the Japanese populations and nucleotide substitution rate, the estimate of the divergence time for the Japanese and Zhe Jiang populations was much greater than that expected for the apparently relictual species distributed in Ariake Bay. The Ariake and Yatsushiro populations formed a single group in the haplotype tree, although the estimate of pairwise Fst showed a significant difference between the populations, probably associated with the differences in frequency of the most dominant haplotype. Accordingly, the two populations seemed to be genetically differentiated from each other, probably due to the geographical isolation.
著者
大森 健策 加納 光樹 碓井 星二 増子 勝男 篠原 現人 都築 隆禎 横井 謙一
出版者
日本魚類学会
雑誌
魚類学雑誌 (ISSN:00215090)
巻号頁・発行日
pp.18-019, (Released:2018-08-20)
参考文献数
64

Large-scale Japanese lakes support many fish species and abundant fisheries resources. However, long-term changes in the fish fauna of such lakes have not been fully investigated, despite recent significant anthropogenic impacts on associated ecosystems. Accordingly, the extensive native and non-native fish fauna of Lake Kitaura, a typical large inland-sea lake (36 km2) in eastern Japan, was investigated based on specimens collected by the staff of Itako Hydrobiological Station, Ibaraki University from 1977 to 1997, plus data from previous studies conducted since the 1950s. In total, 83 species in 35 families have been recorded from the lake from the 1950s to the present decade. The analyses of long-term changes in fish species data since the 1960s demonstrated a sharp decrease in marine, estuarine and diadromous species due to an estuarine barrage (Hitachi River floodgate) established in 1973, the disappearance of nine red-list species (e.g., threatened and near threatened species) following various artificial environmental changes from the 1960s to 1980s, and an increase in introduced exotic and Japanese species after the 1980s.