著者
柴田 輝和
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.59, no.8, pp.1309-1312, 1993-08-25 (Released:2008-02-29)
参考文献数
15
被引用文献数
2 2

The reproductive cycle of the sand snail Umbonium (Suchium) giganteum was investigated on the basis of samples taken monthly during the period from December 1986 to June 1988. Seasonal changes in the gonadal index, size-frequency distribution of the ovarian egg, and the results of a spawning experiment in the laboratory were analyzed to determine the spawning season.The gonadal index was low in August and September, but high during the period from December to June; the index values show a bimodal type of distribution with peaks in November-December and April. This is highly correlated to the seasonal changes in seawater temperature. As indicated from the period of maximum ripeness of gonad and the spawning observed in the laboratory, it is concluded that the spawning of U. (S.) giganteum occurs twice a year, i.e. in winter (December and January) and in late spring to early summer (April, May and June), and that the latter is the main spawning season.
著者
山本 宗一郎 三田村 啓理 黒川 皓平 國森 拓也 堀 正和 荒井 修亮
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.88, no.5, pp.355-364, 2022-09-15 (Released:2022-09-29)
参考文献数
31

マコガレイ成魚30個体に水温・深度ロガーを装着し,2017年7月3日に周防灘姫島地先で放流して2個体から12-1月までのデータを得た。高水温となる9月の2個体の経験水温の最頻値は24-25℃(53.9-57.6%)であった。最高経験水温は27℃に達したが26℃以上の頻度は3.9-4.5%と低かった。深度データからは離底行動が観測され,連続した離底行動後に生息水深,生息水温,分布域等が変化した。よって,天然海域では26℃未満の水温帯で生息可能であり,離底行動は移動に関連していたと考えられた。
著者
高橋 宏司
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.85, no.4, pp.394-397, 2019-07-15 (Released:2019-07-31)
参考文献数
16
著者
佐藤 渡 志子田 立平 埜澤 尚範
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.77, no.4, pp.665-673, 2011 (Released:2011-09-08)
参考文献数
36
被引用文献数
4 4

サンマの高鮮度維持を企図し,魚の生臭みや品質低下の原因となるトリメチルアミン-N-オキシド(TMAO)分解物の生成抑制方法を検討した。その結果,サンマを漁獲後ただちに海水氷に浸漬貯蔵すると分解物の生成が低く,さらにサンマ肉を酸素ガス下,5℃ で貯蔵すると,窒素ガス下に比べ保蔵中のトリメチルアミンおよびジメチルアミンの生成を抑制することができた。また,事前に 1 日酸素ガス処理をしてから冷凍貯蔵した場合も,血合筋で分解物の生成が低く,酸素ガスによる TMAO 分解物生成抑制効果が示された。

1 0 0 0 OA 二枚貝の病気

著者
良永 知義
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.71, no.4, pp.654-657, 2005 (Released:2005-08-24)
参考文献数
22
被引用文献数
1 1
著者
平松 一彦
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.88, no.5, pp.407-408, 2022-09-15 (Released:2022-09-29)
参考文献数
6
被引用文献数
1

加入変動を考慮した資源動態シミュレーションにおいて,バイアス補正項を考慮した対数正規分布が使われることが多い。しかし,加入尾数の変動が過程誤差であれば,バイアス補正により本来の加入尾数の変動と同じ分布は再現できない。一方,観測誤差による見かけ上の変動であれば変動させる必要がない。最大持続生産量(MSY)の推定において,バイアス補正は行わず実際の変動のみでシミュレーションを実施し,バイアス補正ありの結果と比較した。バイアス補正を行う現在の推定方法では,MSY等を過小または過大評価する可能性がある。
著者
高橋 正
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.44, no.8, pp.869-874, 1978-08-25 (Released:2008-02-29)
参考文献数
24
被引用文献数
2 1

In the experiment, to study quantitatively the effect of sweeping membranous light or flashing light on the swimming behaviour of fish, the movement of fish school (yellowtail, body length 40cm) in the water tank (10m×7m, 1m depth) was observed every five seconds. As the results, comparing the swimming speeds between the condition with sweeping membranous light and the condition without it, there was a remarkable lowering of the swimming speed under the condition with sweeping light, And this suppression effect was stronger with higher luminous intensity. From the data of these results, it was suggested theoretically that 37 or more lx of irradiation intensity of the sweeping membranous light on the water surface might have maximum effects on the fish movements in a dark environment.
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, 1952-03-25 (Released:2008-02-29)

The catch of Tribolodon hakonensis has shown a great decrease recently in Chikuma River, middle Japan. From the fact that many young fishes have been caught by the “Ishizuka”, 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. The “Ishizuka”, 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 “Ishizuka” 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 T. hakonensis, which conceal themselves in the space of stones during the winter, escape the mound and are easily trapped. Experimental “Ishizuka” 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 “Ishizuka” destroys tie younger generation of fish. 1 propose to regulate strictly the fishing by “Ishizuka” but rather utilize the mound for the protection of young by the hand of fishermen.
著者
吉田 優花 五十嵐 史子 高橋 希元 大迫 一史 永井 宏史
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
pp.18-00039, (Released:2018-12-04)
参考文献数
16
被引用文献数
1

新鮮なカミクラゲSpirocodon saltatrixは,独特な強い匂いを有することを見出した。その匂いはキュウリ様臭であった。そこで,このカミクラゲの有する特徴的なキュウリ様匂い物質について同定を試みた。GC/MS, GCを用いた官能試験,標品を用いた試験結果から,カミクラゲの有するキュウリ様臭物質は(E)-2-nonenalならびに(E,Z)-2,6-nonadienalと同定した。
著者
田中 邦三 田中 種雄 石田 修 大場 俊雄
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.52, no.9, pp.1525-1532, 1986-09-25 (Released:2008-02-29)
参考文献数
7
被引用文献数
10 13

In the abalone habitat, the disturbed current is caused by the swell and eddy zones are made. The eddy zones acted to collect the swimming larvae. The authors studied the distribution chazacter of swimming and deposited larvae in the nursery ground. The research stations of eddy zones were stable distribution of swimming larvae in average number of 79 individuals per cubic meter of sea water. The density of shelled larvae deposited on the conglomerate in the reef, appeared less than the deposited shelled larvae in the downfall reef on the conglomerates. It was surmised that the swimming larvae were collected by some eddy current, and made abalone habitats. And we studied commonly that these depth were below 7m of open sea with rocky shore.
著者
長岡 千津子 山本 義和 江口 さやか 宮崎 信之
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.70, no.2, pp.159-167, 2004 (Released:2005-06-03)
参考文献数
21
被引用文献数
15 16

2000年4月に大阪湾全域において表層泥を採取し, 重金属濃度 (Hg, Cd, Cu, Zn, Pb, Ni, Mn, Cr, Fe), および, 粒度組成 (泥・砂・礫), 強熱減量, COD, 硫化物について分析を行った。Mn以外の重金属元素は湾奥部や湾東部において濃度が高く, 海水の交換が良い明石海峡, 紀淡海峡付近で低い傾向を示した。底質重金属 (Mnを除く) 濃度と粒度組成, 強熱減量, 硫化物には強い相関性が認められたことから, 底泥の重金属濃度は重金属負荷量以外に, 粒度や有機物によっても大きく影響をうけることがわかった。
著者
大河内 裕之 北田 修一 岩本 明雄
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.64, no.3, pp.462-468, 1998 (Released:2008-02-29)
参考文献数
20
被引用文献数
2 1

The authors consider a method to estimate the age composition of released fish which are recaptured and landed at fish markets, by use of the mean lengths and SDs of tagged fish, the ages of which are precisely known. Since 1988, brand tagged flounder have been released in Miyako Bay simultaneously with those without tags and these data are used to examine the practicality of the method. For the first step of the procedure, the total number of fish by age is estimated employing a normal length distribution by use of the mean lengths and SDs of tagged fish which are h and younger are groups, and then the number of fish by age is calculated for each length class. For the second step, the number of fish older than age h is estimated as the residual number of h and younger age for each length class. The difference between this method and conventional methods is that a normal distribution for the length frequency of fish older than the h age group is not assumed. The cumulative estimated length frequency of age groups fit well the original length frequency and this suggests the method is applicable.
著者
立原 一憲 蛭子 亮制 塚島 康生
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.59, no.9, pp.1479-1488, 1993 (Released:2008-02-29)
参考文献数
15
被引用文献数
29 31

The spawning, embryonic development, and morphological changes of the purplish amberjack Seriola dumerili were observed using specimens reared at the Aquaculture Research Laboratory of Nagasaki Prefectural Institute of Fisheries. Spawning was induced by intra-mascular injection of pituitary homogenate of the chum salmon Oncorhynchus keta and the genital hormone. Spawning occurred 36 hours after hormone treatment and 1, 400, 000 and 7, 000, 000 eggs were obtained in 1990 and 1991, respectively. The eggs were pelagic, spherical, and 1.05-1.20mm in diameter with a single oil globule of 0.22-0.28mm. The larvae hatched out 37 hours after spawning (W. T. 24.6°C). The newly hatched larvae were 2.7-3.1mm in length with 26 myotomes and a single oil globule. The yolk was mostly absorbed on the 4th day after hatching when the larvae attained 3.9mm in length and began to feed on rotifers. In the postlarval stage (6.3mm B. L.) the rudiments of ventral, dorsal, and anal fins began to develop and the vertebra was well ossified. In the juvenile stage (11.2mm B. L.) the membranous fins disappeared and fish gathered around drifting algae. Later in the juvenile stage (35.0mm B. L.) six or seven lateral bands appeared in the trunk as well as a band from the eye to the anterior part of the dorsal fin base. At a body length of 100mm, they reached the stage of young fish, while at a size of over 170mm in body length a yellow vertical stripe appeared from behind the operculum to the caudal peduncle. The smallest size of sexual maturation was thought to be about 600mm. Notochord or standard length at each growth stage was as follows: 2.7-3.9mm (yolk sac stage), 3.9-4.7mm (preflexion stage), 4.8-8.5mm (postflexion stage), 10-100mm (juvenile stage), 100-600mm (young stage), and over 600mm (adult stage).