著者

木村 清志 中村 行延 有瀧 真人 木村 文子 森 浩一郎 鈴木 清 Kimura Seishi Nakamura Yukinobu Aritaki Masato Kimura Fumiko Mori Koichiro Suzuki Kiyoshi

出版者

三重大学水産学部

雑誌

三重大学水産学部研究報告 (ISSN:02875772)

巻号頁・発行日

no.10, pp.p71-93, 1983-10

被引用文献数

3

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1980年4月から1982年5月までの期間に,三重県英虞湾湾口部のアマモ場で,ビームトロールにより魚類の採集を行い,このアマモ場の魚類相とその季節的変化について,次のような結果を得た。1. 採集された魚類は13目53料117種27,293個体であった。個体数はゴンズイ,ギンポ,アミメハギ,ハオコゼ,ヨウジウオ,アナハゼの順に多く,この6種で全体の8割程度を占める。 2.各魚種の出現状態から,これらを周年定住種,季節的定住種、偶発種に分け,さらにいくつかのグループ,サブグループに細分した。 3. 種数は夏から秋に増加し,冬に減少する。4. 個体数のピークは5,6月,8月,10,11月,1,2月の年4回みられ,これらほスジハゼ,アミメハギ,ハオコゼ,アナハゼ,アサヒアナハゼ,ゴンズイ,ギンポ,サビハゼ,カワハギなどの変動に起因している。 5. このアマモ場の魚類相は,ヨウジウオ,ハオコゼ,アミメハギの周年にわたる出現,冬から春のギンポ,アナハゼ,6月のサビハゼ,8月のゴンズイの大量出現,夏から秋にかけてのベラ料やヒメジ科魚類の多種にわたる出現によって特徴づけられる。このような魚類相は暖流外海性の特徴で,黒潮沿岸各地のアマモ場の魚類相と共通性が高い。しかし,一方でほそれぞれのアマモ場の魚類相には特異性もみられる。 6. ギンポの大量出現ほ伊勢湾周辺のアマモ場の特徴である。 7. 英虞湾湾口部のアマモ場では有用椎幼魚の出現比率が低い。したがって魚類生産に関する限り,このアマモ場の水産的価値は小さいと判断される。Fish fauna of the Zostera bed at the mouth of Ago Bay, Mie Prefecture were studied by monthly samplings with a small beam trawl from April 1980 to March 1981 and from June 1981 to May 1982. The results obtained are summarized as follows : 1 ) 27,293 individuals (13 orders, 53 families, 117 species ) were collected in the Zostera bed. Plotosus lineatus, Enedrias nebulosus, Rudarius ercodes, Hypodytes rubripinnis, Syngnathus schlegeli,and Pseudoblennius percoides were dominant species. About 80 percent of the specimens collected belonged to these six species. 2 ) Each species of fish collected was divided into three categories, i. e. residents, seasonal residents, and casual species. Residents and seasonal residents were subdivided into a few of groups and subgroups as follows : (I) Residents ; fishes appearing in the Zostera bed all the year round. Group A ; fishes residing during the major part of their life cycle, and using the Zostera bed as their nursery, feeding and spawning grounds. Group B ; fishes inhabiting mainly during juvenile stage, and using the Zostera bed principally as a nursery ground. Group C ; fishes inhabiting chiefly during adult and subadult stages, and using the Zostera bed primarily as a feeding ground. Group D ; fishes universally distributed in the bay and commonly appearing in the Zostera bed. Group E ; fishes which may reside during all seasons in a very small number in the Zostera bed. (II) Seasonal residents ; fishes which spend a certain definite season in the Zostera bed. Group F ; fishes residing during juvenile and young stages and using the Zostera bed only as a nursery ground. Subgroup a ; fishes which spend a long perid of time ( more than four months) in the Zostera bed. Subgroup b ; fishes which spend a short period of time ( less than three months) in the Zostera bed. Group G ; fishes residing from juvenile to adult or subadult stages. Subgroup c ; fishes which inhabit the Zostera bed in a large number, and which use the Zostera bed as nursery, feeding, and spawning grounds. Subgroup d ; fishes which reside in the Zostera bed principally as a nursery ground. (III) Casual species ; fishes appearing casually in the Zostera bed. 3 ) Number of species increased from summer to autumn by recruitment of juveniles belonging to seasonal residents and casual species, and then decreased in winter. 4 ) Total number of individuals increased in May or June, August, October or November, and January or February. This fluctuation was caused by seasonal changes of populations of the following nine species ; Acentrogobius pflaumi, Rudarius ercodes, Hypodytes rubripinnis, Pseudoblennius percoides, P. cottoides, Plotosus lineatus, Enedrias nebulosus, Sagamia geneionema, and Stephanolepis cirrhifer. 5 ) The fish fauna of the Zostera bed at the mouth of Ago Bay was chracterized by the following : ( 1 ) Syngnathus schlegeli, Hypodytes rubripinnis, and Rudarius ercodes residing all year round. ( 2 ) Appearance in great number of Enedrias nebulosus and Pseudoblennius percoides from winter to spring, of Sagamia geneionema in June, and of Plotosus lineatus in August. ( 3 ) Subsistence of many species of fishes belonging to Labridae and Mullidae from summer to autumn. 6 ) Appearance of Enedrias nebulosus in large number was a peculiar feature of the fish fauna of the Zostera bed in and around Ise Bay, central Japan. 7 ) As far as the fish production in concerned, the Zostera bed at the mouth of Ago Bay had little significance for inshore fishery because there the juveniles of useful fishes were very few.