著者

中村 薫

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

no.29, pp.p225-238, 1980-12

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It has been commonly known that the feeding habits of decapods are affected by inevitablemoltings for their developments. In this report, the quantitative methods were applied tofeeding experiments of individual crayfish, Procambarus clarkii, for the purpose to clarify therelation of feeds to the molting cycle. Some kinds of pellets were prepared, especially suchpellets as containing much cellulose (90%) or oil (14.1%) were used for the examinations of nutritional consideration. Such item as the body weights at different stages on the moltingcycle, the diurnal amount of consumed pellets, and in some cases the amount of feces were weighed. After that, the feed conversion factor of each molting cycle, the amount of consumed pellets during one cycle/ (the body wt. of postmolt-the body wt. of intermolt), wascalculated. Further, the values of the molting power were introduced here as the indicativesof the degrees of water absorption at the molting time, which were calculated as (the body wt. ofpostmolt-the body wt. of premolt)×100/ the body wt. of premolt.As results, the diurnal amount of consumed pellets showed a distinct variation following thelapse of molting stages. Its pattern had the 1st maximum, which is also the greatest value,at the short postmolt period and the 2nd maxima were recognized in some cases before thenext molting. Such greatest values correspond to the 2-3% of their body weights, and thesummed feeds of the diurnal amounts during one molting cycle occupy about 23% of the bodyweight of intermolt. Considering with the experimental results of cellulose feeding, it suggestedthat the internal factor(s) of a feed-control mechanism if existed in the crayfish might participateprimarily with the hemolymph concentration(s)of absorbed nutritive(s) rather than the physical factor as the capacity of the digestive tract, that is the stomach and intestinal volume. Inaddition, as the pellets of much contained oil gave comparatively a high efficiency to the molting power and the feed conversion factor, it seems that lipid may propose a physiological interestfor the nutritional approach to the molting development.1. 個別飼育法でペレット飼料を給餌し,アメリカザリガニの日間摂餌量を求め摂食と脱皮成長との関係を調べた。2. 日間摂餌量は脱皮周期上の位置により著しい変動を示した。そのパターンは脱皮後期に最大値をもつ極大点を示すこと,第2極大期を次回脱皮の前に経る場合もあること,等が明らかにされた。3. 最大日間摂餌量はその体重の2-3%程に当たること,脱皮の1周期上の積算摂餌量は個体の大きさに関らず脱皮間期体重の約23%を占めることが算出された。4. セルロース給餌との比較実験の結果,摂食の制御機序には胃の容積と云った機械的要因よりも血リンパの栄養分が第一義的に関与する可能性の高いことが示唆された。5. 脂質高含有飼料の栄養試験により当該飼料は脱皮周期へは促進的効果を示さないが,脱皮時の吸水作用を高め且つ飼料係数を小さくする働きを窺わせ,脱皮成長に対して効率の良い飼料になり得る可能性を示した。

著者

不破 茂 花田 芳裕 フワ シゲル ハナダ ヨシヒロ FUWA Shigeru HANADA Yoshihiro

出版者

鹿兒島大学水産學部

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

vol.60, pp.13-23, 2011

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日本近海の捕鯨記録から太平洋戦争終期の昭和19年から昭和23年にかけて,甑島ではマッコウクジラ(Physeter macrocephalus)やイワシクジラ(Balaenoptera borealis),ナガスクジラ(Balaenoptera physalus),シロナガスクジラ(Balaenoptera musculus)が捕獲されたことが明らかとなった。本研究の目的は九州本土に近い甑島で行われた捕鯨の概要を明らかにし,近海捕鯨における甑島での捕鯨がどの様な位置づけであるかを検討することにある。

著者

片岡 千賀之

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

no.31, pp.p57-80, 1982

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Due to progress in fisheries capitalization, boat fisheries had been realized through motorization in order to expand their fishing towards offshore, while in the coastal fishings, set net fisheries hadimproved with changes in the shape given to these art and the materials used.In case of yellowtail set net fisheries, such changes have evolved through four steps as follows:1) The traditional yellowtail catching methods were fixed gill net and triangular set net madeof rice straw. But a unique type so-called "yellowtail drift gill net" was used in MiyazakiPrefecture. This was invented by Kiemon Hidaka and his son Kameichi Hidaka in 1875.2) In 1892, the triangular set net made of hemp was invented by Kameichi Hidaka and his son Eizaburo Hidaka. This has been found effective and has been adopted in big-scale catch consequently contributing much to high productivity.3) In 1910, the same persons introduced for the first time the square set net made of hemp. Traditionally, it was made of rice straw used only for capture of tuna. With this new modification, it was possible to catch not only yellowtail but also tuna and was made popular throughout Japan.4) In 1919, Terushige Horinouchi in Kochi Prefecture introduced the trap set net. Thismethod, although effective, expanded slowly because the trap caught not only yellowtail, a prefered specie, but the miscellaneous fish caught in a big quantity. However, during the gainedpopularity especially with low-income fishermen due to its low cost and more stable capture compared to square set net method (3).The innovations have progressively contributed to high production on the national level.However in Miyazaki Prefecture as well as in the other places, fluctuations in catch had been experienced every now and then with peaks observed more or less every ten years.Such fluctuations in catch depend upon enviromental conditions such as natural cycles in water current andother man-made factors such as overfishing brought about by new innovation in fishing gears. Before these new innovations were introduced, no problem existed regarding utilization offishing grounds especially in undevelopment areas. This was due to the fact that only moving fishing gears were commonly utilized. When a shift from moving fishing gears to fixed gill net and eventually to set net occurred, several problems arose mainly; a) Claims on fishing groundareas which was of common use for all. b) Manpower, the set net methods require a number of people in the community for the operation.Due to the existence of such problems, it was necessary to create regulations for proper utilization of fishing grounds. In 1901, the "Meiji" Fisheries Law was established for the first time defining fishing rights were necessary to use the fishing ground. In 1910 and in 1933 at the hight of the "Showa" economic crisis, the law was revised in order to motivate establishment of fisheriesco-operative for the benefit of all. As a result, the set net fishing right were given more to theseco-operatives allowing them to engage in bisiness, nevertheless the fisheries law didn't discribe any precedence of its ownership and management.

著者

伊牟田 直輝 中村 薫 平田 八郎

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

vol.43, no.1, pp.p61-67, 1994-12

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To examine artificial pellets as a substitute for feed of the larval firefly Luciola picticollis, feeding experiments were conducted with commercial prawn pellets for 190 days. About 100 larvae just after hatching were accommodated into a 5l polyurethane stock tank provided with pebbles, aeration and filtration apparatus, and fed with living snails Semisulcospira libertina. Before beginning of feeding experiments, 20 individuals as the control and 10 individuals as the first experiment were sampled from the stock and transferred into each 1l tank provided with aeration and only a stone as a shelter. They were fed with the snail meat or pellets. After 60 days, two groups of 10 individuals were added to the feeding experiment as the second and third. Mean plus S.D. of the control body length was 17.7±6.5mm in 190 days. That of the first experiment was 4.6±0.7mm in 80 days. That of the second or third experiment was 10.3±3.4mm or 7.4±1.8mm each in 130 days. Means plus S.D. of the body weight at 2, 3, 4, 5, 6, and 7 instars of the control were 3.1±0.1mg, 6.9±0.1mg, 11.6±1.0mg, 44.7±1.4mg, 74.3±17.8mg, and 196.8±74.7mg. Those at 2, 3, 4, and 5 instars of the experimental group were 2.1±0.3mg, 4.2±0.8mg, 6.5±0.5mg, and 19.8±6.2mg. The pellets were able to maintain growth of firefly larvae, though they were not nutritionally excellent. From the binocular observation of larval feeding on pellets, maxillae were found to elongate and function in like manner of a drill.1)カワニナの代替にクルマエビ用の配合餌料を用い,ゲンジボタル幼虫の餌料飼育試験を行なった。 2)カワニナ餌区(対照区)を1つ,配合餌料区(実験区)を3つ設定し,190日間飼育実験した。実験期間中水温は,12°Cから27°Cの範囲で変化した。 3)平均体長±標準偏差は,対照区において190日目で17.7±6.5mm,実験1区は80日目で4.6±0.7mm,実験2区と実験3区は,各130日目で10.3±3.4mmと7.4±1.8mmであり,カワニナの方が配合餌料より早い伸びを示した。しかし生存率は逆に後者の方が良かった。 4)平均体重±標準偏差は各齢毎の測定で,対照区;2齢3.1±0.1mg,3齢6.9±0.1mg,4齢11.6±1.0mg,5齢44.7±1.4mg,6齢74.3±17.8mg,7齢196.8±74.7mg,実験区;2齢2.1±0.3mg,3齢4.2±0.8mg,4齢6.5±0.5mg,5齢19.8±6.2mg,となり齢数が加わるにつれて増加した。同時に体重の個体差も増加が示された。 5)配合餌料はカワニナ餌より成長効果が劣った。しかし,配合餌料でも摂餌は持続し成長も少なからず示されたこと,また生存率はカワニナ餌よりも良かったこと,等から本配合餌料は代用餌としての可能性を残す。 6)ゲンジボタル幼虫の摂餌行動上,従来不明であった小腮の役割に関して新知見を得た。

著者

皆元 国

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

no.4, 1956-01

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(1) It is possible for us to get good results by this method in the following cases. (a) The relation between latitude and beclination is inappropriate for the ex-meridian observation. (b) The zenith distance of the sun's meridian passage lies within 10 degrees. (c) Special cases such as the tuna fishery by Long-Line in the southern sea. (2) In the above mentioned cases noon position may be fixed by merely observing the sun's meridian passage. (3) Error of the possition between above mentioned method and the ordinary one is not of a great difference.

著者

川村 軍蔵 不破 茂

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

no.23, pp.p9-18, 1974-12

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"Even when the fishing is carried out under the constant fishing effort, catch fluctuates largely. Its fluctuation depends on two main factors, i.e. phychophysiological phase of fish and the fish population size in the fishing ground. To clarify these factors, the analysis of the catch fluctuation is needed. By use of Auto-correlation Coefficient, the authors carried out the analysis of periodic fluctuation of the catch of spotted mackerel in the fishing ground off the Yaku Island in Kagoshima Prefecture. In this study, it was clarified that when the number of the catch per one operation is less than 25 fish, the catch depends mainly on the chance, and when it is over 25 fish, the catch depends on the fishing ability of the crew, which is fixed by the experience and the strength of the crew. Then, in this analysis, the authors used the catch-data obtained in 1971 and 1972, and of the crew who showed an average catch irrespective of the catch per one operation, and who was looked upon as the one with much experience and full strength. Moreover as the catch was supposed to be affected by the winds and waves because of the smallness of the fishing boat, the fluctuation of the scale of wind waves in the fishing ground was analyzed. The following results were obtained. (1). In the wind waves fluctuation, significant cycles consisting of 3.4 days, 5.2 days and 32.7 days were observed in 1972. (2).In the catch fluctuation, significant cycles consisting of 3.8 days and 8.8 days were observed in 1971; and those of 5.1 days and 9.6 days in 1972; and the former in 1972 was considered to be the cycle affected by the wind waves. (3). No cycle agree with that of the moon-age was observed in the catch fluctuation. (4). It was assumed that the periodic fluctuation of catch is to be caused chiefly by both emigration and the immigration of the spotted mackerel in the fishing ground round the Yaku Island."

著者

今田 清二 コンダ セイジ KONDA Seiji

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

vol.3, no.1, pp.254-260, 1953-11

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国際連合の国際港委員会は1951年「大陸棚及び関係事項についての条項案」を採択し,国際連合加盟各国の意見を求め,他の事項と共に公海制度の国際法々典化の歩を進めている。然るに公海漁業に関する範囲において,前記条項案の理論には二つの重大な問題がある.本文はその間題を指摘し且つこれに関する私見を明らかにすることを目的とする。

著者

内山 正樹 日高 正康 東川 勢二

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

vol.43, no.1, pp.p41-50, 1994-12

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In January, 1985, the mooring buoy for Kagoshima-Maru was newly installed in Yamagawa Harbor, Kagoshima Prefecture. The typhoons that approached or landed at Kagoshima Prefecture in the past were investigated, and Makurazaki Typhoon which is regarded as the typhoon of largest class in the postwar period was supposed, and as for the buoy, it was considered fundamentally that in the wind of maximum velocity 35m/s (on average for 10min), the ship can be moored safely by using only the chain (40mm) of the ship. Since then up to today, the mooring for harborage has been carried out at the time of 27 typhoons. Among them, the typhoon No. 13 on September 3, 1993 was the largest typhoon that the ship encountered at Yamagawa Harbor, and the maximum instantaneous wind velocity of 47.0m/s and the barometric pressure of 936.2 hPa were recorded, but the ship was able to be moored and shelter safely. It is considered that the structure and strength of the buoy were as planned and designed, and it was able to be proved.昭和60年1月鹿児島県山川港にかごしま丸係船浮標を新設した。浮標(ブイ)は過去に鹿児島県に接近上陸した台風を調べ,戦後最大級の台風とされる枕崎台風を想定し,最大風速35m/s(10分間平均)の風の中で,ブイに本船チェーン(40mm)だけで安全に係留出来ることを基本に考えた。以来今日まで,27個の台風時に係留避泊した。この中で平成5年9月3日の台風13号は本船が山川港で受けた最も大きな台風であり,最大瞬間風速47.0m/s,最低気圧936.2hPa.を記録したが安全に係留,避泊することが出来,ブイの構造,強度が計画設計通りであったことが証明出来たと考えられる。

著者

今井 健彦

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

vol.43, no.1, pp.p1-9, 1994-12

被引用文献数

1

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This paper deals with flow-profiles around an enlarged solid model of netting which was set into an experimental flume tank on every half angle of Θ, (range from 0 to 3Θ of setting angles), to clarify flow distribution around the model. In this case Θ means the angle of attack when mesh-hall faded out from the projective plane. A thin film flow-meter with corn shaped probe was used in the experiment. Measurements were carried out on 110 fixed points, 24 points around mesh, and 5 points inside mesh-halls at every attack angles on a horizontal plane. The flow-speed was maintained at 10 cm/s, and Reynolds number at 1.9×10^3. From the resultant profiles, the fluid-dynamical force acting on each leg was similar with the case larger than 3Θ of attack angles.

著者

西 徹

出版者

鹿児島大学

雑誌

鹿児島大学水産学部紀要 (ISSN:0453087X)

巻号頁・発行日

no.39, pp.p81-98, 1990-12

被引用文献数

1

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The thirteenth fishing operation with a long-line having five branch lines was carriedout in the Eastern Indian Ocean by "The T.S. KAGOSHIMA-MARU (G.T.1,293 Tons)", ofthe Faculty of Fisheries, Kagoshima University, from May 19 to 31, 1987.The hourly variations of the depth of hooks in the tuna long-line and the hooking depthof tunas and marlins were investigated.The numbering method of hooks was adopted to name the first hooks lifted in each basket as No.1 and sequently as No.2, No.3, No.4 and No.5. The results of the analysis are asfollows:1. The recorded depths of hooks ranged from 69 m to 103 m (89 m in average) for No.1 andNo.5 hooks, 111 m to 154 m (134 m in average) for No.2 and No.4 hooks and 122 m to 178 m(154 m in average) for No.3 hooks.2. The patterns of hourly variations of the depth recordings were classified into threecategories of A, B and C. In the case of the high current velocity obtained from thedrift of the long-line, all the data were classified into B or C category.3. The maximum differences between measured and calculated depths of the hooks were,in average, 16 m for No.1 and No.5 hooks, 20 m in same for No.2, No.4 and No.3 hooks.4. The hooked ratio of yellowfin tuna in each branch line was high in No.3 and No.4 hooks showing same value of 27.4%, followed by No.2, No.1 and No.5 hooks in order. Fromthese results, the main hooking stratum was estimated to be at the depths of 120 m to150 m.5. The hooked ratio of bigeye tuna was 33% for No.3 hooks, accounting for 30% of totalcatches, with 73.3% of total bigeye tuna catch attained No.2, No.3 and No.4 hooks.From these results, the main hooking stratum of bigeye tuna was estimated to be at the depths of 140 m to 170 m.1987年5月19日から31日の期間,インド洋東部海域において,鹿児島大学水産学部練習船かごしま丸(総トン数1293屯)を使用して5本付延縄による13回の釣獲試験操業を実施した。鮪延縄の釣針の経時変化とマグロ,カジキ類の釣獲深度について検討を試みた。枝縄別の釣針深度は1,2,3番の枝縄に装着した3台の自記式深度計の記録から求め,マグロ,カジキ類の釣獲深度については釣獲野帖から各枝縄別釣獲データを深度別に集計して釣獲層を推定した。釣針の番号の命名方法は各鉢ごとに最初に揚げられた釣針を1番とし,以後順番に2,3,4,5番釣針と呼ぶことにした。今回の解析の結果は次の通りである。1. 1,5番釣針の実測深度は69~103m(平均89m),2,4番釣針で111~154m(平均134m),3番釣針では122~178m(平均154m)であった。2. 投縄後,釣針が安定するまでの所要時間は1,5番釣針では平均すると約12分,2,4番釣針では平均20分,3番釣針では18分を要している。3. 深度記録の経時変化のパターンをA型,B型,C型の3種類に分類して各々の記録を図示した。A型は流速0.3ノット以下であり釣針の計算深度と実測深度の差が極めて小さい。釣針の振幅は小さくてその周期も緩やかに変動している。B型とC型は釣針の計算深度と実測深度の差が20m以上あり,幹縄はカテナリー曲線を描いていないと推測される。B型は釣針の上下動の振幅が10~20mで,周期が15~60分ぐらいで変動しておりC型は振幅は10~30m,周期が1~5時間と大きなウネリを伴って上下動している。縄の漂移から求めた流速が大きい時はすべてB型かC型に分類された。4. 水中での釣針の最大振幅は枝縄別の平均値をとると,1,5番釣針では16m,2,4番釣針と3番釣針では20mと同じ値であった。5. 深度計を取り付けた鉢の釣針にキハダが釣獲された記録から20m以上も上方に枝縄を持ち上げている例を図示した。6. キハダの枝縄別釣獲割合は3番と4番で高く,27.4%と同じ値を示し,以下2,1,5番釣針の順となっている。これらの結果からキハダの主釣獲層は120~150m深と推定した。7. メバチの枝縄別釣獲割合は3番釣針で33%と全体の3割を占め,2,3,4番釣針でメバチ全釣獲の73.3%に達している。これらの結果からメバチの主釣獲層は140~170m深と推定した。8. 各枝縄間の釣獲差について,t検定を行った。キハダについては4番と5番釣針間には釣獲差について5%水準で有意差が認められたが,その他の枝縄間ではキハダ,メバチ共に枝縄間には5%水準以下で釣獲差に有意差は認められなかった。9. 水温鉛直分布によるキハダやメバチの釣獲深度は水温躍層内に存在していた。