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

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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

立原 一憲 木村 清朗

出版者

公益社団法人 日本水産学会

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.54, no.1, pp.55-60, 1988-01-25 (Released:2008-02-29)

参考文献数

22

被引用文献数

9 7

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Observations on the life history of land-locked Ayu Plecoglossus altivelis were made in Lake Ikeda, in Kagoshima Pref., from 1981 to 1985. In this study, two types of Ayu were recognized in its social behavior of immature adult fish in the Lake. One is territorial type and the other is non-territorial type. Some differences were found in the shape of dorsal fin and the color pattern of body between two social types. The territorial fish have longer posterior dorsal fin rays and darker fin membranes than those of non-territorial ones. The former have three clear yellow oval marks on their gill covers and anterior body sides, however, the latter have only one mark and its coloration is pale or faint. Thesevariations are not related with body size and sexuality but with the social type. It is suggested that large and clear yellow marks are signal for recognition of their status among owners of territory and for showing the domination of owner to non-territorial fish. Thus, these differences between two social types of Ayu show a possibility of being applied to the evaluation of fishing ground of this species.

著者

立原 一憲 木村 清朗

出版者

公益社団法人 日本水産学会

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.57, no.12, pp.2187-2192, 1991-12-25 (Released:2008-02-29)

参考文献数

29

被引用文献数

6 7

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Observations on the life history of the land locked ayu Plecoglossus altivelis altivelis were made in Lake Ikeda, Kagoshima Prefecture, 1981 to 1986. The gonads of males and females developed rapidly from August and the GSI of both sexes indicated the highest values in October. The diameter of ovulated oocytes in the body cavity ranged from 0.74 to 0.99mm and the relation between the number and standard length of fish was represented as E=0.00188χL3.418. The spawning season of the ayu in the lake was from early October to late November. The ayu spawned mainly at shore lines shallower than about 30cm in depth and the substrate of reds consisted of fine gravel, ranging mostly from 3-10mm in diameter. The sex composition of the ayu crowding the spawning site was not the same throughout the spawning season. Males predominated in the early period of the season, and females in the latter. The male fish matured simultaneously and most of them crowded at spawning grounds. On the other hand, the fully matured female appeared at the spawning site one by one, while the immature ones dispersed around the site in low density. It is suggested that this mode of spawning in the ayu may be one of the important factors for sustaining its population land locked in Lake Ikeda.

著者

立原 一憲 木村 清朗

出版者

日本水産學會

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.54, no.7, pp.1107-1113, 1988

被引用文献数

1 4

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A study on the life history of land-locked ayu <i>Plecoglossus altivelis</i> was made in Lake Ikeda, Kagoshima Prefecture, from 1981 to 1986.<br>Like amphidromous ayu, the life span of the land-locked fish in this lake is usually only one year and most of them die after spawning in autumn. However, a few individuals of land-locked ayu passing over the second winter are found in the lake.<br>The specimens counting 7, 810 of ayu in the lake were collected during this study and 73 of them were thought to be the over-wintered ones, because they had a conspicuous spawning mark on the embeded part of their scales. None of 0⁺ fish had any such scales. The amounts of fat tissue around viscera of mature ayu decreased in the spawning season from early October to late Novermber. Also, the condition factor of ayu caught in November showed very wide range from 0.6 to 1.7. The fish whose condition factor was less than 0.9 had exteremely shrunk stomach without any food, whereas the fish of more than 1.3 in condition factor had normal stomach containing a small amounts of diatoms and blue-green algae. All specimens of 1₊ fish, which were collected after December, had recovered their fat tissue and begun to grow again. Thus, it is suggested that the survival of ayu after spawning season depends on the degree of stomach shrinkage and adequate intake of food. Some of them grew 150mm in standard length or more by the next autumn.<br>The specimens of mature 1⁺ fish which were caught at a spawning ground in October suggests that some of the over-wintered ayu in the lake are able to attain maturity in second spawning season.

著者

立原 一憲 木村 清朗

出版者

日本水産學會

巻号頁・発行日

vol.57, no.5, pp.789-795, 1991 (Released:2011-03-05)

著者

立原 一憲 四宮 明彦 木村 清朗 今井 貞彦

出版者

日本生態学会

雑誌

日本生態学会誌 (ISSN:00215007)

巻号頁・発行日

vol.38, no.2, pp.159-167, 1988-08-31

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Observations on the development of aggressive behavior of Japanese perch, Coreoperca kawamebari, were made over a 1-year period. Newly hatched larvae aggregated at the water surface and showed no aggressive behavior. Several days after yolk sac absorption, larvae dispersed from the water surface to the substrate and began to feed and fight. Chasing and lateral displays as seen in adult fish were firstly observed at this time, and a dominance hierarchy was evident at 50 days after hatching. Dominant individuals formed their territories after 50 days and gradually enlarged them as body size increased. The behavioral ontogeny of this fish is divisible into four phases, i. e. aggregation, dispersion, developing of aggressive behavior and territorial phases, and these correspond with four different stages of growth, namely prelarva, postlarva, juvenile and young stages, respectively.

著者

木村 清朗 長田 芳和

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.38, no.4, pp.425-429, 1992-02-29 (Released:2010-06-28)

参考文献数

14

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日本産バラタナゴは, 在来のニッポンバラタナゴRhodeusocellatus smithiiと中国渡来のタイリクバラタナゴR. ocellatus ocellatusに分けられていた.Acheilognatus smithiiとR. kurumeusの完模式標本を観察したところ, A. smithiiは, 体側に長い明瞭な暗色縦帯をもち, 背鰭と轡鰭の最初の主鰭条がやや強く, 分節が少ないので, バラタナゴとはいえない.R. kurumeusの形態は, ニッポンバラタナゴによく一致した.タイリクバラタナゴの日本への侵入は第二次大戦中であったので, 1900年採集のR. kurumeusの完模式標本, 副模式標本1個体, ほか10個体の標本は, すべてニッポンバラタナゴと判断された.したがって, ニッポンバラタナゴの学名としてR. ocellatus kurumeusが正しい.一方, A. smithiiは, カゼトゲタナゴR. atremiusとスイゲンゼニタナゴR. suigensisによく似るが, どちらとも判定できなかった.