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海産ミドリムシ赤潮による魚類の斃死機構解明に関する研究
https://fra.repo.nii.ac.jp/records/2003359
https://fra.repo.nii.ac.jp/records/20033595deb9fdf-6f08-4d91-b15b-392fc0e4dd33
Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
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公開日 | 2024-04-25 | |||||
タイトル | ||||||
タイトル | 海産ミドリムシ赤潮による魚類の斃死機構解明に関する研究 | |||||
言語 | ja | |||||
タイトル | ||||||
タイトル | Studies on Death of Fish Caused by Red Tide | |||||
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 | |||||
著者 |
松里, 寿彦
× 松里, 寿彦× 小林, 博 |
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抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | In order to clarify the mechanism of the death of marine fish caused by natural red tide, the influences of the red tide on the red sea bream, Chrysophrys major, and the cultured yellow tail, Seriola quinqueradiata, were experimentally investigated in the use of the cultured marine plankton, Hemieutreptia antiqua HADA (Order Euglenoida), as natural red tide sea water. The plankton was cultured in large quantities by using the medium of SWM-III, under about 6,000 lux illumination and in the constant temperature room of 20°C. In spite of an environmental characteristic that the sea water of this plankton was nearly saturated with oxygen, most of the bream started to die at the density above 2,700 cells/ml when the bream was thrown in the red tide of pH 8.3. In this case the death of the bream seems to be related with the number of the plankton and pH of the red tide, while there was no influence on the bream in the filtrate from the red tide and the surface part of the decayed and decomposed red tide. Breathing rate, heart pulsation rate and the others were also investigated in both the species affected by the red tide. In particular, the pathological inspection of the branchia was carried out in the yellow tail, and the transparent viscous substance was found between each gill-fillament. This substance is distinguished from a lot of mucous fluid secreated after the death and perhaps prevents the ventilation of water flow. The viscosities of the red tide and its various treatment solution were measured by means of Ostward's viscosity meter and showed no remarkable difference from that of normal sea water. When the red tide was filtered through the silk net with the opening of 95 micron, the filtration rate decreased with the lapse of the time and the rate was related with pH of the red tide. And the opening was observed to be plugged by the red tide blooms or the transparent viscous substance. On the other hand, the filtrate from the red tide and its various treatment solution were injected into the abdominal cavity of the bream as well as into the blood vessel through the cannula of dorsal artery in the yellow tail. Any injected material did not kill the fishes at least within 48 hours. The blood gas contents of both artery and venous blood were investigated in the yellow tail suffering from the anoxia to be compared with those from the red tide. Artery blood sampling was taken from the cannula of the dorsal artery and venous one directly from the heart. Under the usual anoxic anoxia, it was considered that a process of asphyxiation occurs in the dissolved oxygen concentration below about 1.7 ml/L. And the surfacing phenomena were not seen at the concentration above 2.0 ml/L. When the yellow tail began to swim madly about in the red tide, the dissolved oxygen in the environment was still above 5 ml/L, and the artery blood oxygen content of the fish was 5 to 6Vol.% though it decreased with the lapse of the time. In this case, however, the oxygen level of the blood gas content just before the death was similar to that of the usual asphyxiation. In the aquatic respiration of the yellow tail, the oxygen utilization and the ventilation volume were measured. Under the influence of the red tide, the utilization decreased remarkably in comparison with the same ventilation volume in normal sea water, although the ventilation volume decreased before the death, too. Moreover, the respiratory characteristics of the blood were also investigated in the yellow tail affected by the red tide as shown in Fig. 16, in which the blood has a tendency to be condensed. From these results mentioned above, the cause of the death of the fish attributed to the red tide of Hemieutreptia antiqua HADA seems to be based on asphyxiation which is brought about by the interception of the ventilation water in the branchial owing to the red tide blooms. | |||||
言語 | en | |||||
抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | 本研究は,昭和44年~47年,瀬戸内海において,養殖魚などに大被害をもたらした,海産ミドリムシ(Hemieutreptia antiqua HADA, Eutreptilla sp.等)赤潮による魚類の直接的な斃死因,斃死機構を明らかにすることを目的とし,考え得る多くの斃死因,斃死機構について実験的に検討を加え,真の斃死因,斃死機構の把握に努めた。実験は主として,培養海産ミドリムシとハマチ Seriola quinqueradiata, マダイ Chrysophrys major を用いて呼吸生理の面を中心に行なった。主な実験の結果は次のとおりである。1. ハマチ,マダイ共に培養海産ミドリムシ海水中でも速やかに斃死に至る。2. 海産ミドリムシ培養沪液,枯死分解上澄液,破砕液などは,それらの液内飼育および腹腔内注射,血管注人によっても,ハマチ,マダイに対し致死的影響を与えない。3. 海産ミドリムシ海水中では,溶存酸素量が充分存在するにもかかわらず実験供試魚の動脈血中酸素ガス含量の著しい低下が認められ,また,呼吸水量が同一であっても,供試魚による酸素利用率も低下する。海産ミドリムシ海水による供試魚の血液性状の変化は,供試魚が窒息に陥っていることを示す。4. 海産ミドリムシ海水中で斃死に至った供試魚の鰓は粘性物質に被われ,しばしば鰓弁間に海産ミドリムシ細胞崩壊物からなる固形物が認められる。5. 海産ミドリムシによる海水の粘性の変化は非常に小さいが,篩網を用いた沪水試験において海産ミドリムシは,容易に粘性物質放出,組織崩壊を起こし,それらは網目を被い,沪水率の低下をもたらす。以上の実験結果および漁場における海産ミドリムシ赤潮による被害の実態などから,本赤潮による魚類の直接的斃死因は,赤潮生物の鰓に対する物理的影響に基づく魚の側のガス交換機能の障害による急性の窒息性窒息である。具体的には,海産ミドリムシが鰓表面で粘性物質放出,細胞崩壊を起こし,それらが鰓全面を被うとともに鰓弁間に固形物を形成し,鰓薄板面の呼吸水の流通阻害を引き起こし,それにともない,魚は急激な窒息に陥ることが明らかとなった。 | |||||
言語 | ja | |||||
bibliographic_information |
ja : 南西海区水産研究所研究報告 en : Bulletin of the Nansei Regional Fisheries Research Laboratory 巻 7, p. 43-67, ページ数 25, 発行日 1974-08 |
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出版者 | ||||||
出版者 | 南西海区水産研究所 | |||||
言語 | ja | |||||
出版者 | ||||||
出版者 | Nansei Regional Fisheries Research Laboratory | |||||
言語 | en | |||||
item_10002_source_id_9 | ||||||
収録物識別子タイプ | PISSN | |||||
収録物識別子 | 0388-841X | |||||
item_10002_source_id_11 | ||||||
収録物識別子タイプ | NCID | |||||
収録物識別子 | AN00181988 | |||||
情報源 | ||||||
識別子タイプ | Local | |||||
関連識別子 | nnf_k_7_43 | |||||
関連サイト | ||||||
識別子タイプ | URI | |||||
関連識別子 | https://agriknowledge.affrc.go.jp/RN/2010102421 | |||||
言語 | ja | |||||
関連名称 | 日本農学文献記事索引(agriknowledge) |