著者
竹内 俊郎
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.76, no.2, pp.298-303, 2010 (Released:2010-05-13)
参考文献数
40
被引用文献数
6 4
著者
川尻 稔
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.17, no.7, pp.206-210_2, 1952

The catch of <i>Tribolodon hakonensis</i> has shown a great decrease recently in Chikuma River, middle Japan. From the fact that many young fishes have been caught by the &ldquo;Ishizuka&rdquo;, Nagano Prefectural Government prohibited this particular gear since 1946, however, there were heard varied opinions among fishermen as to its effect and, as the result, to remove the regulation.<br> The &ldquo;Ishizuka&rdquo;, set up in early winter, is a mound composed of stones as, large as or larger thna humna head, measuring 50cm high and 100 to 150cm in diameter at bottom, the mound is built in the water 70 to 80cm deep with graduated slope toward the mainfolow of the river, also the entire &ldquo;Ishizuka&rdquo; is covered with straw-mat except the sloped part where the stones are flattened mixed with smaller gravels. In early spring, the mound is surrounded by bamboo-blinds and a trap is set against sloped part, then the stones are picked up piece by piece. The fish, mostly <i>T. hakonensis</i>, which conceal themselves in the space of stones during the winter, escape the mound and are easily trapped.<br> Experimental &ldquo;Ishizuka&rdquo; numbering 17 were set in November 1948-'49, and the fish 4699 caught following spring were studied on age and length. The age determination by scale on these fish showed 59.5% of one year old, 19.8% of two, 16.6% of three and other older. It is thus apparent that the &ldquo;Ishizuka&rdquo; destroys tie younger generation of fish.<br> 1 propose to regulate strictly the fishing by &ldquo;Ishizuka&rdquo; but rather utilize the mound for the protection of young by the hand of fishermen.
著者
梅津 武司
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.32, no.4, pp.352-376, 1966-04-25 (Released:2008-02-29)
参考文献数
120
被引用文献数
1 1
著者
白井 和雄
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.23, no.11, pp.723-728, 1958-03-25 (Released:2008-02-29)
参考文献数
6
被引用文献数
1

In the previous papers on the radioelements in skipjacks, 1)2) the identification of Cd113m as a main contaminant and the presence of Zn65, Fe55 and a trace of Ba140-La140 were reported. The present paper deals with a contaminated big-eyed tuna, Parathunnus mebachi, caught at a station (12°17'N, 167°04'E) in the Pacific Ocean on Oct. 20, 1956. Data on the specimen are given in Table 1 and the radioactivity of tissues and organs is shown in Fig. 1. The ashes of liver, pyrolic caeca, kidney, red muscle and ordinary muscle were fractionated by the group separation method using carriers and the considerable amount of radioactivity was found in Group II (Table 2). Radioactive elements contained in Group II were proved to be mostly composed of Cd113m and Cd115m by the further fractionation (Fig. 2). The existence of these nuclides was confirmed by the half lives of Cd fractions (57-71 days when estimated directly and 43-44 days when traversed with 263.9mg/cm2 Al absorber), energy of β-ray (1.6 Mev) calculated from absorption curves (Fig. 3) and energy of γ-ray (1.1 Mev). Group IIIB and IV obtained from the liver, pyrolic caeca and kidney were supposed to be chiefly consisting of Zn65 and Sr90-Y90 respectively, judging from the decay and energy of β-ray, measured on the unrefined fractions (Fig. 6, 7). Member of Group IIIA were not thoroughly examined in spite of higher activity due to the disturbance of phosphate. Further confirmation of these nuclides will be dealed in the following papers.
著者
大西 修平 山川 卓 赤嶺 達郎 筒井 義郎 山根 承子
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.84, no.4, pp.720-727, 2018

<p> 漁業者行動は通常,合理性に基づいてモデル化される。一方,個々の漁業者は不確実性下で異なるリスク態度をとる事実も知られる。不確実性下の意思決定の観察結果は,期待効用仮説による説明としばしば異なる。過度に単純化された漁業者行動モデルは,漁業管理方策への適用にあたり注意が必要であろう。行動経済学の研究成果は,意思決定の合理性の破れがプロスペクト理論で説明できることを示したが,理論の有用性は漁業管理研究では十分に知られていない。本研究ではプロスペクト理論の可能性を概観し,漁業者の様々な性向を探究する。</p>
著者
平松 一彦 寺内 一美
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.86, no.4, pp.288-294, 2020-07-15 (Released:2020-08-05)
参考文献数
23
被引用文献数
2

マサバ対馬暖流系群のVPAによる資源評価では,毎年資源量推定値が下方修正されるレトロスペクティブパターンが存在した。このVPAでは年齢別漁獲尾数と資源量指標値がデータとして用いられ,自然死亡係数一定,漁具能率一定等が仮定されている。パターンが生じる原因を探るため,VPAで使用されるデータや仮定を変更してレトロスペクティブ解析を行いパターンの変化を見た。結果は,資源量指標値を用いない場合及び漁具能率の年変化を仮定した場合パターンがほぼ無くなり,漁具能率一定の仮定が原因となっている可能性が示された。
著者
嶋田 宏 金森 誠 吉田 秀嗣 今井 一郎
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.82, no.6, pp.934-938, 2016 (Released:2016-11-22)
参考文献数
20
被引用文献数
6 23

2015年10月中旬から11月下旬に,北海道函館湾において,魚介類に斃死をもたらす渦鞭毛藻Karenia mikimotoiによる有害赤潮が北日本で初めて発生した。赤潮の発生期間中に斃死した魚介類は,サケOncorhynchus keta,スルメイカTodarodes pacificusおよびエゾアワビHaliotis discus hannaiの3種に及んだ。K. mikimotoi赤潮(3,200-11,500 cells/mL)の発生時における水温および塩分は,それぞれ9.9-15.7℃および31.8-32.2の範囲にあった。K. mikimotoiが北日本へ分布を拡大した原因としては,対馬暖流/津軽暖流による自然な来遊,あるいは船舶バラスト水による人為的輸送が想定される。
著者
田島 研一 高橋 恒人 絵面 良男 木村 喬久
出版者
日本水産學會
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.50, no.1, pp.145-150, 1984
被引用文献数
1 16

In a previous paper, we examined the toxicity of the extracellular protease of <i>A. salmonicida</i>, Ar-4 (EFDL) on yamabe (<i>Oncorhynchus masou f. ishikawai</i>) and goldfish (<i>Carassius auratus</i>). From these results, we considered the protease secreted by this bacterium was a causative agent of furunculosis.<br> In this paper, we observed enzymatic properties of the purified protease. The results obtained were summarized as follows:<br> 1. The molecular weight of purified protease was estimated to be 71, 000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis.<br> 2. The purified protease showed maximal activity at pH 9.4 and 50°C. It was stable over the pH range 5.0 to 10.0 and was completely inactivated by temperature at 56°C.<br> 3. The protease was presumably classified an alkaline serine protease and it showed chymotryptic properties since it was significantly inhibited by diisopropylfluorophosphate (DFP) and tosyl-phenylalanine-chloromethyl ketone (TPCK) and hydrolyzed <i>N</i>-benzoyl-L-tyrosine ethyl ester (BTEE).
著者
山下 栄次 松野 隆男
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.58, no.12, pp.2277-2282, 1992 (Released:2008-02-29)
参考文献数
25
被引用文献数
3 4

A series of new apocarotenoids, micropteroxanthins, has been isolated from the integuments of the black bass Micropterus salmoides, namely α-micropteroxanthin A, α-micropteroxanthin B, β-micropteroxanthin, and 7, 8-didehydro-β-micropteroxanthin. These structures have been de-termined to be (3S, 6S)-11', 12'-dihydro-10'-apo-ε-carotene-3, 10'-diol, (3R, 6S)-11', 12'-dihydro-10'-apo-ε-carotene-3, 10'-diol, (3R)-11', 12'-dihydro-10'-apo-β-carotene-3, 10'-diol, and 3(R)-7, 8-didehydro-11', 12'-dihydro-10'-apo-β-carotene-3, 10'-diol, respectively. The possible metabolic pathways of carotenoids to new apocarotenoids, micropteroxanthins, by an eccentric cleavage in the black bass have been proposed.
著者
貞方 勉
出版者
公益社団法人 日本水産学会
雑誌
日本水産學會誌 = Bulletin of the Japanese Society of Scientific Fisheries (ISSN:00215392)
巻号頁・発行日
vol.66, no.6, pp.969-976, 2000-11-15
参考文献数
19
被引用文献数
2 2

産卵期と幼生ふ出期およびその間の海深別の採集個体の年齢群を解析することにより, ホッコクアカエビの着底以降の海深別の分布と移動を調べ, これまでに得られた知見と合わせて本種の生活史を明らかにした。本種は浮遊幼生期を経て着底後, 成長にしたがって海深の深い方へ移動する。海深400-600mが交尾・産卵海域で, 主群は雄では3,4,5歳, 雌では6,8,10歳である。3-4月に産卵した抱卵個体は, 約10ヶ月の抱卵期間後の1-2月に海深200-300mに移動して幼生ふ出をおこなう。
著者
大河内 裕之 山根 幸伸 有瀧 真人
出版者
公益社団法人日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.74, no.3, pp.389-394, 2008-05-15
被引用文献数
1 9

岩手県宮古湾で産卵直後のニシン成魚を採捕し,2年間で合計500尾を標識放流した。放流後3年2ヶ月間で合計114尾の標識魚が再捕され,再捕率は22.8%であった。これらの再捕経過から,宮古湾で産卵を終えたニシンは速やかに産卵場を離れて北上回遊し,夏季には宮古湾の300km北方の北海道噴火湾海域に生息すると考えられた。放流翌年の産卵期には合計32尾が成熟して宮古湾内で再捕され,これらは噴火湾から南下した産卵回帰個体と判断された。本州沿岸で産卵するニシンは,標識魚と同様の回遊生態を持つと考えられた。
著者
上田 正 武田 道夫
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.43, no.9, pp.1115-1121, 1977-09-25 (Released:2008-02-29)
参考文献数
5
被引用文献数
3 4

The results of methyl mercury (MeHg) analyses of the muscle tissues and the livers of 39 specimens of yellowfin tuna, Thunnus albacares, from the Middle Pacific, the West pacific, and the East Indian Oceans are presented.The correlations between the levels of MeHg and total mercury (T-Hg) were signiflcant (at 0.01 level) in both muscle tissues and liver. The difference between the MeHg and the T-Hg levels was insignificant (at 0.01 level) by t-test in both dark muscle and liver. On the other hand, the MeHg levels of dorsal muscle were significantly lower than the corresponding T-Hg levels, the difference being approximately 0.04μg/g. The level of MeHg in dark muscle and liver, respechively, correlated significantly with that of dorsal muscle (at 0.01 level). The dark muscle contained a higher level of MeHg than the dorsal muscle, the difference being about 0.03μg/g, while the liver contained less than either (about 0.07μg/g). On the basis of the statistical evaluation described above, the order of mercury levels among the muscles and the liver was estimated as follows; T-Hg of dorsal muscle≈T-Hg of dark muscle≈MeHg of dark muscle>MeHg of dorsal muscle>MeHg of liver≈T-Hg of liver.
著者
末廣 恭雄
出版者
公益社団法人 日本水産学会
雑誌
日本水産学会誌 (ISSN:00215392)
巻号頁・発行日
vol.2, no.6, pp.307-311, 1934-03-15 (Released:2008-02-29)
参考文献数
10
被引用文献数
1 1

It is well known that fishes while jostling in the fishing net vomit their taken food during the manipulation of the fishing. Whether this vomiting is simply a mechanical disgorging due to the violent jostle of the fish in the net, or a real vomiting produced by the excitement of the nervous vomiting center as is observable in the case of higher vertebrates, is still unknown. Indeed, it has not yet been proved, whether the low class vertebrate, such as the fish, has the vomiting center, or not. The writer used apomorphine hydrochloride to test if fishes react to the emetic. 0.2-1.0 c.c. of its 0.5% solution was injected into the body cavity of various sea fishes, to which sufficient food had previously been given. The reaction was extremely remarkable; almost all the fishes thus treated vomited entirely their stomach contents soon after the injection of the emetic. The control experiment was also done by the injection of the distilled water. Negative reaction was, however, obtained. Since, thus, apomorphine hydrochloride is equally applicable as an emetic to the fish and it is the stimulant of the vomiting center in the higher vertebrates, the writer makes suggestion on the existence of the vomiting center in the fish.