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養殖マダイ産出卵の移送機構に関する研究 (2)
https://fra.repo.nii.ac.jp/records/2008250
https://fra.repo.nii.ac.jp/records/20082507e61d6db-3dff-4012-b90d-a5511a5a001a
| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||||||||||||||||||||
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| 公開日 | 2024-06-20 | |||||||||||||||||||||||
| タイトル | ||||||||||||||||||||||||
| タイトル | 養殖マダイ産出卵の移送機構に関する研究 (2) | |||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||
| タイトル | ||||||||||||||||||||||||
| タイトル | Research on Transportation and Distribution of Eggs of Cultured Red Sea Bream (2) | |||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||
| 言語 | ||||||||||||||||||||||||
| 言語 | jpn | |||||||||||||||||||||||
| 資源タイプ | ||||||||||||||||||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||||||||||||||||||||
| 資源タイプ | departmental bulletin paper | |||||||||||||||||||||||
| アクセス権 | ||||||||||||||||||||||||
| アクセス権 | metadata only access | |||||||||||||||||||||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||||||||||||||||||||
| その他（別言語等）のタイトル | ||||||||||||||||||||||||
| その他のタイトル | 卵・仔稚魚の分布特性について | |||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||
| その他（別言語等）のタイトル | ||||||||||||||||||||||||
| その他のタイトル | Distributional Pattern of Eggs and Larvae | |||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||
| 著者 |
松浦, 秀喜
× 松浦, 秀喜
× 有薗, 真琴
× 角田, 信孝
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| 抄録 | ||||||||||||||||||||||||
| 内容記述タイプ | Abstract | |||||||||||||||||||||||
| 内容記述 | The spontaneous spawning of the cultured red sea bream, Pagrus major, in a pen of Senzaki Bay, Yamaguchi Prefecture has been previously reported in relation to the influences on its natural resources. This paper deals with the horizontal and vertical distributions of eggs and larvae occurred in this bay and neighbouring bay. The material treated in this paper were all collected by a larva net, 71.5cm in diameter, 200cm in length with NGG 54 and 38 mesh, during the period from 1975 to 1977. The sampling by the larva net was made in three areas innermost small inlet in which the cultured pen is located, Senzaki Bay including this inlet, and neighbouring Fukagawa Bay. 1) Senzaki Bay has a steep bottom covered largely with mud, and seems to be a comparatively closed bay, based on its shape. While Fukagawa Bay is somewhat open and the major part of the bottom is covered with sand, and rocks or gravels are scattered in the peripheral shallow waters less than 10m depth, occupying about half of the bay. The most juveniles were collected from these shallow waters within the present research areas. Therefore, the shallow waters may be a suitable nursery ground for the early demersal life of the red sea bream juveniles. 2) Of the daytime samples by the horizontal tows made at five layers (0, 5, 10, 15, 20m depth) in inlet and the central part of Senzaki Bay, three types of fish eggs and 11 species or groups of larvae were selected to examined. The distributional layer of these eggs varied with the egg types, depending chiefly upon their specific gravity, the time lapsed from the spawning, and environmental factors such as salinity and water movement. The sea bream type eggs, composed of mainly red sea bream, were collected chiefly near surface layer, but the eggs at advanced stages were also collected at deeper layers. On the other hand, the red sea bream larvae appeared to be concentrated at 10m layer, together with other species such as anchovy, dragonets, scorpionfishes, trigger fish and flounder. The size composition of the larval red sea bream at each depth-layer were as follows: it ranged widely from 2 to 15mm in total length (TL) at 0-5m layer, the mode was 7mm in TL at 10m layer and 9mm in TL at 20m layer. It was supposed that larvae larger than 8mm in TL prefered to deeper layers. 3) The distribution of the sea bream type eggs and the newly hatched red sea bream larvae were examined by the vertical tows within the inlet. The occurrences of each developmental stage varied with time and space. The distributional patterns seemed to be influenced by two types of currents; the drift current and the tidal current. The former might influence more significantly upon the egg distribution. Although the major part of eggs was transported outside of the inlet, few larvae just hatched was found remaining within the inlet. 4) The sea bream type eggs collected by the oblique tows in the whole area of Senzaki Bay were found at the same developmental stage and at nearly same densities, except for the inlet, where the density was much lower than the other area of the bay. These results indicated that these eggs were diffused in a short time to the boundary area between the inlet and the bay. Thereafter they were rapidly transported over the Senzaki Bay. Eggs at advanced stages inclined to stay at the inner part of the bay, and a part of them to be mixed vertically. The distributional patterns of eggs of the other species in this bay were rather different from that of the sea bream type eggs. At Fukagawa Bay, however, the sea bream type eggs, which were all transported from the outside of bay, were very scarcely distributed. On the basis of the changes in distribution of newly spawned and one-day eggs, the water of the bay seems to be exchanged at least once a day in both Senzaki and Fukagawa Bay, although more obviously in the latter. 5) Based on the oblique tow samples made in Senzaki Bay, the red sea bream larvae were found most abundantly at the inner part of the bay, like the other cooccurred species originated from both outside and inside of the bay. While at Fukagawa Bay, the larvae appeared to be transported from the outside of bay, and less concentrated. These results appeared to show that the larval distribution was determined mainly by the tidal current. 6) Of the larval red sea bream captured by the larva net, larvae just hatched to 4mm in TL were scarce and 5-7mm larvae were dominant in Senzaki Bay, but 3-10 mm larvae were equally captured in Fukagawa Bay. While larvae of the other species were found at every developmental stage and over the whole area of the bay. These results showed that most eggs and newly hatched larvae of the red sea bream originated from the pen might not remain within Senzaki Bay. It was speculated that they might be dispersed outside the bay during several days after spawning. Further studies would be necessary especially on the process of transformation from pelagic larval stage to demersal juvenile stage. | |||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||
| 抄録 | ||||||||||||||||||||||||
| 内容記述タイプ | Abstract | |||||||||||||||||||||||
| 内容記述 | 養殖マダイの自然産出卵の移送機構を明らかにするため,1975年から3ヶ年養殖場を中心として仙崎湾および深川湾で親魚の産卵実態と卵仔稚魚の分布を調査した.本報では養殖場水域,仙崎湾および深川湾の3水域で稚魚網を用いて各層水平曳,表層水平曳,鉛直曳,傾斜曳を試み,卵·仔稚魚の水平,鉛直分布についていくつかの知見を得たので報告する.1. 養殖場水域を含む仙崎湾はやや内湾性の性格を有し,急深で大部分泥質によって占められている.深川湾は外海的性格を有し,全域砂質によって占められ,面積約1/2に相当する10m以浅域に岩礁·転石帯が点在する.深川湾の10m以浅域は着底期以降のマダイ幼稚魚の生息適地となっており,両湾の中で最もマダイ幼稚魚資源の豊富な水域である.2. 養殖場水域および仙崎湾央において各層(0,5,10,15,20m層)水平曳採集を行い,昼間におけるタイ型卵およびマダイ仔稚魚の鉛直分布を明らかにした.あわせて3種の卵と11種の仔稚魚についても明らかにした.卵の分布層は卵の形質,産卵後の経過時間,塩分·流動環境などによって種類·発生段階毎に変化に富んでいる.タイ型卵は発生初期にごく表層に分布し,後期発生段階になると鉛直混合が進み,分布範囲が深層へ拡がる.仔稚魚の分布は多量に標本の採集されたマダイ,カタクチイワシ,ネズッポ科,カサゴ科,カワハギ,ヒラメ科とも10m層に集中してみられた.マダイ仔稚魚の全長と分布層の関係についてみると,0~5m層ではふ化直後から15mm台の範囲で幅広く出現し,10m層では7mm台が,20m層では9mm台が最も多く採集され,深い層では大型の仔魚の採集される割合が高い傾向がうかがわれる。3. 鉛直曳採集の結果から養殖場水域におけるタイ型卵およびふ化直後の仔魚の水平分布についてみると,産卵後の経過時間にともなう分布範囲,密度の変化は吹送流の生じない条件のもとでは潮汐の影響がみられるが,吹送流が生じるとむしろその影響が顕著となる.採集量からみて、この湾入部にふ化仔魚として残留する量はきわめて少ない。4. 傾斜曳採集の結果によると,養殖場水域から仙崎湾へ移送された卵は同日産出卵が湾口域までほは同密度で出現する。このことから,前水域との境界域で急速に分散が進み,表層に分布する卵の移送はさらに速くなるものと思われる.深川湾では湾外から移送されるタイ型卵の分布密度はきわめて低く,分布パターンにも一定した傾向はみられない。また,表層水平曳採集の結果から仙崎·深川湾におけるタイ型前日産出卵と小型単脂卵の分布を潮汐,風向風力成分,塩分と対応させたところ,卵の分布はそれらの相互作用により移送され,特に吹送流による影響を強く受けていることがわかる.これらのことから卵の湾内外の交流は早ければ1日以内に行われる可能性のあることが示唆された.5. 傾斜曳採集による結果からマダイ仔稚魚の水平分布についてみると,仙崎湾では常に湾奥部に高密度域がみられ,湾外産卵種のカタクチイワシ,サバ科および湾内外産出種のカサゴ科,ネズッポ科の仔稚魚にも同様な傾向がみられた.深川湾は湾外産卵種に湾口からの移送パターンがみられるが,仙崎湾のような集積域はみられない.水平,鉛直分布の様式からみて,仔稚魚の移送は卵とは異なり,主として潮汐流による移送,集積が行われていることが示唆された.6. 仔稚魚の全長組成についてみると,仙崎湾ではマダイ仔稚魚のふ化直後から4mmまでの出現がまれで,5~7mmサイズにモードがみられる.一方,他の魚種はふ化直後からかなり発育の進んだ仔稚魚まで幅広く出現している.このように,全長組成や分布パターンからみて,養殖場に由来するマダイ仔稚魚は湾内にそのまま残留し着底する単純な移送過程ではないように推定された.今後は調査水域の拡大とともに浮遊期から着底期に移行する過程の調査へと発展させる必要がある。 | |||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||
| 書誌情報 |
ja : 西海区水産研究所研究報告 en : Bulletin of the Seikai Regional Fisheries Research Laboratory 巻 56, p. 89-109, ページ数 21, 発行日 1981-03 |
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| 出版者 | ||||||||||||||||||||||||
| 出版者 | 西海区水産研究所 | |||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||
| 出版者 | ||||||||||||||||||||||||
| 出版者 | Seikai Regional Fisheries Research Laboratory | |||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||
| ISSN | ||||||||||||||||||||||||
| 収録物識別子タイプ | PISSN | |||||||||||||||||||||||
| 収録物識別子 | 0582-415X | |||||||||||||||||||||||
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| 収録物識別子タイプ | NCID | |||||||||||||||||||||||
| 収録物識別子 | AN00393385 | |||||||||||||||||||||||
| 情報源 | ||||||||||||||||||||||||
| 識別子タイプ | Local | |||||||||||||||||||||||
| 関連識別子 | snf_k_56_89 | |||||||||||||||||||||||
| 関連サイト | ||||||||||||||||||||||||
| 識別子タイプ | URI | |||||||||||||||||||||||
| 関連識別子 | https://agriknowledge.affrc.go.jp/RN/2010232905 | |||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||
| 関連名称 | 日本農学文献記事索引(agriknowledge) | |||||||||||||||||||||||
