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シャコOratosquilla oratoria(De Haan)の生物生産過程に関する生態学的研究
https://fra.repo.nii.ac.jp/records/2008198
https://fra.repo.nii.ac.jp/records/2008198d6701c4b-4a37-41b8-94a1-222d3436580d
| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2024-06-20 | |||||
| タイトル | ||||||
| タイトル | シャコOratosquilla oratoria(De Haan)の生物生産過程に関する生態学的研究 | |||||
| 言語 | ja | |||||
| タイトル | ||||||
| タイトル | The Ecological Study of Mantis Shrimp Oratosquilla oratoria (De Haan) with Reference to Its Bio-production Processes | |||||
| 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 |
山崎, 誠
× 山崎, 誠 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Mantis shrimp, Oratosquilla oratoria (De Haan), is a Stomatopod crustacean inhabiting the sandy mud bottom in the coastal waters of Japan, and one of the important species for fisheries at many localities. Until now, only a few reports deal with the population dynamics or the ecological aspects of mantis shrimp. So, there has been a strong need to elucidate the mode of life of this species for establishing the fishing technique aimed at stock management and for seeking the possibility of culturing and farming. In this paper, the ecological aspects of adult mantis shrimp such as the growth of gonad and body and the food intake for sustaining their growth and maturation are explained from the bio-production processes. Its life cycle is then clarified from these interrelations. Samples of mantis shrimp were taken from offshore Okunai in Mutsu Bay, Aomori Prefecture. Samples for the observations of the reproductive cycle, body growth and gut contents were caught bimonthly with the bottom gill nets which were set at eight stations in this area. Samples for the observations of the diurnal activity with feeding were caught with the same nets as mentioned before at a station 400 m from the shore. As another approach to the problem of viability, rearing experiments were performed in aquariums of about 400 l capacity with running water systems at a training center of the culturing fisheries of Minami-Kayabe senior high school, Hokkaido Prefecture. In these aquariums, the shrimps were divided into three different groups by body length, and were individually measured and weighed monthly. The food supplied during the rearing experiments was chilled fresh euphausiids. Remains and faeces were removed with siphons within periods no longer than four days. The developmental processes of germ cells in both sexes were categorized by means of histological examination. On this basis, the maturation processes were defind into four stages for ovaries and five for testes. Further, comparing the ratio of individuals having characteristics of maturation to the whole number in the sample and the values of the gonad index (the ratio of the wet weight of gonadal tissues to the body weight), the annual reproductive cycle in the female population of mantis shrimp was broadly classified into the following five different periods : (1) Recovering period (August-September), (2) Developing period (October-November), (3) Pre-maturing period (December-February), (4) Maturing period (March-May), and (5) Spawning period (June-July). Similarly, the cyclical reproductive processes in the male population were divided as follows: (1) Recovering period (July), (2) Developing period (August-September), (3) Pre-maturing period (October-December), (4) Maturing period (January-April), and (5) Sperm ejecting period (May-June). From the analysis of the polymodal length frequency distributions in natural population and the observation of moulting in the rearing population, the growth in length of adult showed like steps when moulting, which occurred in August to October. The regression equation of body length showed a retrogressive geometric growth pattern which formulated is as follows : Ln+1=0.755Ln+4.743 where Ln and Ln+1 are body length in cm. before and after an ecdysis respectively. From this equation and the relations of body weight to body length gained monthly measured from reared individuals, the annual changes of shrimp weight showed a large increment after moulting as observed in the change of length. This was a common feature in both sexes, but with females the increase and decrease of body weight with maturing and spawning was pronounced. The rearing individuals were dissected bimonthly and at various times during moulting and spawning to separate each body components such as integument, muscle, hepatopancreas and ovary. The relation of the dry weight of each body component to body weight was calculated. The body length at a certain arbitrary month was put in the length-weight relationship above-mentioned and the body weight derived in such a manner was put in the regression equations of each body component and body weight. Thus, the seasonal changes of dry weight of body components were obtained. In the changes of dry weight of integument and muscle, there were no large increment except during moulting of both sexes. There was a big increase in male hepatopancreas after moulting and little until the next one. In females, there was a gradual decrease after the rapid increment of post-moulting and was smallest after spawning. Further, there was a large seasonal change in the dry weight of ovary as observed in the hepatopancreas, suggesting the existence of a close relationship with spawning. The weight increment with moulting was the result mainly of newly formed integument and muscle. Judging from the diurnal activity and the presence of organisms in guts each season, the diurnal pattern of activity of mantis shrimp can be said to be nocturnal in spring and autumn, day and night in summer and inactive in winter. Mantis shrimp fed on a high proportion of Crustacea, Mollusca and Pisces. The daily amounts of food taken by adult individual reared with euphausiid were smallest at levels of 20 to 70 mg dry weight per day in December to February. Thereafter, an increase in amount continued and reached 270 to 370 mg between August and October. After reaching the maximum value, the amount decreased rapidly to 100 mg in November and December. The seasonal variations of assimilation efficiencies showed little fluctuation and maintained the level at about 90%. The caloric values of each body component were calculated by multiplying the dry weight of each body component by the caloric value per unit weight. The annual changes of accumulation and consumption of energy were derived from the difference in bimonthly caloric values measured for each body component. In the muscle, there was a large accumulation of energy in September, which reflected moulting. In female hepatopancreas, there was some accumulation of energy immediately before moulting and at about two months after moulting and there was some consumption of energy from April to July, and in September the time after moulting. On the contrary, in male hepatopancreas, there was no marked change until the time before moulting. There was a large accumulation of energy in the integument from September to October in both sexes, which reflected the formation of new integument and its hardening after moulting, although, there was also a large consumption coinciding with moulting in September. In the ovary, there was a remarkable accumulation and consumption from April to June, which coincided with spawning. The process of individual production may be described using the following equation : Gb+Gg+R=A=C-F (Gb: body growth, Gg: gonad growth, R: metabolic loss, A: assimilation, C: food intake, F: rejection). The amounts of energy required for the growth of body and gonad were derived from the differences between the accumulation and consumption of energy of body components mentioned above. The amount of metabolic loss was derived from calculations based on standard metabolism. From the sum of the amounts of body growth, gonad growth and metabolic loss, the energy of assimilation was calculated. Further, the energy of food intake was derived from the energy of assimilation by means of assimilation efficiencies. In adult shrimps, 190 to 240 kcal per year was ingested, and about 90% of it was assimilated. Most part of the assimilated energy was metabolic loss. The remaining calories (19-26 kcal in female, about 12 kcal in male) were accumulated in each body component for growth, although, 3-5 kcal (about two per cents of ingested energy) was released out of the body as a result of moulting. Furthermore, in females, 7-14 kcal was spent for the growth of ovary, and 85-90% of it was released during reproduction at spawning. Gross growth efficiencies were indicated 9-11% in females and 5-6% in males. Analyzing the interrelation of gonad growth, body growth and food intake, i. e., the series of energy exchange that started at food intake, going through food assimilation and growth of gonad and body, the life cycle of adult mantis shrimp was categorized to four periods as follows: 1) moulting and body growth period (August-November), 2) hibernating period (December-February), 3) gonad growth and maturing period (March-May), and 4) spawning period (June-July). | |||||
| 言語 | en | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | シャコは,わが国浅海域の砂泥底に広く分布し,地域的には重要な漁獲対象種となっている.これまで,シャコの個体群動態やその基礎的な生態学的事象を扱った知見は少なく,資源管理を考慮した漁業技術を確立する上でも,増養殖の可能性を探りだす上でも,本種の生活様式の解明が強く求められている.本研究は,シャコの生物生産を中心とした生態学的事象を明らかにする立場から,生殖腺と体の成長およびこれを支える食物摂取について明らかにし,これらの相互関連からシャコ成体の生活環を把握した.得られた成果は,次のように要約される.(1) シャコ成体の生殖膝の成熟過程は,雌雄生殖細胞の発育に伴う形態的特徴から,雌で4期,雄で5期に区分される,さらに,生殖腺の成熟過程と生殖腺重量の季節的な変化から,シャコ成体の生殖問期は,雌個体群では,回復期:8~9月,発育期:10~11月,前成熟期:12~2月,成熟期:3~5月,産卵期:6~7月,雄個体群では,回復期:7月,発育期:8~9月,前成熟期:10~12月,成熟期:1~4月,放精期:5~6月という1年を1周期とする過程をたどる.(2) 陸奥湾におけるシャコ自然個体群の体長頻度分布の解析および室内水槽内での飼育個体群の脱皮の様相から成長を検討した結果,シャコの体長増大は脱皮により非連続的になされ,体長12cm以上の成体では脱皮期間は8月から10月,成長式はLn+1=0.755Ln+4.743 であらわされる退行性等比成長型を示す.体重の変化は,体長と同様脱皮後に大きな増大を示し,このことは雌雄個体に共通しているが,雌個体ではさらに卵巣の成熟と産卵に伴う体重の増減が顕者であり,雄個体と大きな述いがある.(3) 外骨格,肉質部,肝膵臟および卵巣の乾燥重量の周年変化から判断して,脱皮現象に伴う重量の増大は,主として新生殻と体肉質部の増重によってもたらされる.また,雌の卵果の乾燥重量は,肝膵臓と共に季節的に大きな変化を示し,産卵に関わる両者の関連性の強いことを示している。(4) シャコは,食物獲得を導因として,春·秋には夜行型,夏は周日型,冬は不活発となる日周期をとる.また,甲殻類,貝類,魚類を高い割合で摂食する.(5) オキアミ餌料で飼育した成体個体の日間摂餌量は,12月から2月にかけて 20~70mg dry wt の極小値をとり,その後増加して8~10月には 270~370mgの最大値をとるが,11·12月には急激に減少してほぼ100mg 以下となる.また,同化効率は,季節による大きな変動が少なく,概ね90%ほどの水準にある。(6) 個体の生産過程は,摂取量-排出量=同化量=体成長量+生殖腺成長量+代謝損出量であらわされ,シャコ成体個体は,年間 190~240kcal を摂取してそのほば90%を同化する。この同化エネルギーの大きな部分は呼吸として失われるが,残余のエネルギーは雌での 19~26kcal,雄での約12kcal が体を構成する各部位に蓄積されて成長という形をとる.このうち,脱皮によって雌雄とも 3~5kcal 約2%が体外に放出され,また,雌では,7~14kcal が生殖腺の成長にあてられるが,産卵によってその85~90%が生殖物質として体外に失われる。摂取したエネルギーが新しい組織に転換される割合(粗成長効率)は,雌で9~11%,雄で5~6%である.(7) 生殖腺の成長および体成長と食物消費量との相互関係を検討し,摂餌にはじまり食物同化をへて成長に至るまでの一連のエネルギー転換の観点からみると,シャコ成体の生活環は,次の4期に整理される.1)脱皮と体成長の時期(8月~11月),2)越冬期(12月~2月),3)生殖腺の成長·成熱期(3月~5月),4)産卵期(6月~7月). | |||||
| 言語 | ja | |||||
| bibliographic_information |
ja : 西海区水産研究所研究報告 en : Bulletin of the Seikai Regional Fisheries Research Laboratory 巻 66, p. 69-100, ページ数 32, 発行日 1988-03 |
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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 | |||||
| item_10002_source_id_9 | ||||||
| 収録物識別子タイプ | PISSN | |||||
| 収録物識別子 | 0582-415X | |||||
| item_10002_source_id_11 | ||||||
| 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_66_69 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://agriknowledge.affrc.go.jp/RN/2010392707 | |||||
| 言語 | ja | |||||
| 関連名称 | 日本農学文献記事索引(agriknowledge) | |||||
