著者

NAOKI KUMAKURA KIYOSHI SAKAI FUMIO TAKASHIMA

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.69, no.3, pp.495-504, 2003 (Released:2009-03-31)

参考文献数

37

被引用文献数

9

---

The annual reproductive cycle, including the first maturity of ovarian development and plasma levels of testosterone (T) and estradiol-17β (E2), was examined in female Japanese catfish Silurus asotus reared under natural conditions. In addition, the possible period that final oocyte maturation and ovulation can be induced by human chorionic gonadotropin (hCG) injection were investigated. Results showed that female Japanese catfish matured 1 year after hatching under reared conditions. The beginning of vitellogenesis was in March and ovarian development and plasma T and E2 levels peaked in June. Thereafter, the gonadosomatic index gradually decreased to October and regression of oocytes at the tertiary yolk globule stage was observed. Female Japanese catfish could be induced to final oocyte maturation and ovulation by hCG treatment during the period from June to September. In addition, the fertilization rates were relatively high and stable during this period. These results suggest that yearling female Japanese catfish can be used as brood stock for seed production. This is the first study to investigate the annual reproductive cycle in Japanese catfish. These data will provide useful information regarding brood stock management and seed production.

著者

Kaworu Nakamura

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.60, no.3, pp.271-274, 1994 (Released:2008-06-30)

参考文献数

10

被引用文献数

3 6

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To prove air breathing, common carps Cyprinus carpio acclimated at 27°C were subjected to the following experiments after a 3 h precooling period in water by decreasing the temperature to 17°C. 1) Each fish with a plugged oesophagus was accommodated in a respiratory chamber connected to gas meters for measurements of concentration changes of O2 and CO2 at 17°C. 2) Each group of five fish was exposed to 17°C air to examine its 100% survival time. Over time, the O2 concentration decreased and that of CO2 increased. The CO2 concentration showed a saturation curve. Mean respiratory rates in the initial period of 1-1.5 h were 51±24.2ml O2 per kg•h and 24±5.8ml CO2 per kg•h. The 100% survival time with a 3 h precooling was 4.5 h. As a conclusion, carp breathe following an incomplete CO2 excretion even in air.

著者

Kazuya Taniguchi Kazuya Kurata Takayoshi Maruzoi Minoru Suzuki

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.60, no.6, pp.795-796, 1994 (Released:2008-06-30)

参考文献数

8

被引用文献数

12 42

著者

Takashi Yada Fuminari Ito

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.64, no.5, pp.694-699, 1998 (Released:2008-06-30)

参考文献数

34

被引用文献数

6 6

---

Sexual differences in survival and changes in plasma ion levels after transfer from neutral water to acid water prepared with sulfuric acid were examined in medaka Oryzias latipes. In acid water at pH 3.5 and 3.8, survival of female fish was better than male. During exposure to acid water at pH 4.1, there was no mortality in either sex. Male fish showed a transient decrease in the plasma sodium level 24 h after transfer to pH 4.1, whereas there was no change in the female. The plasma level of sulfate was not affected in the female, but a significantly high level was consistently observed during the exposure in the male. In both sexes, the activity of gill Na+, K+-ATPase increased within 24 h after transfer to pH 4.1, and this high level was maintained for 1 month. Treatment with short day-photoperiod (8L:16D) caused a cessation of spawning due to inactivation of the testis and ovary. Transfer to acid water caused a decline in plasma sodium only in male fish, but not in female even under a short photoperiod. These results indicate that female medaka are more tolerant to acidic environment, possibly with a greater osmoregulatory ability than male fish.

著者

Tomoko Seki Toru Taniuchi Hideki Nakano Makoto Shimizu

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.64, no.1, pp.14-20, 1998 (Released:2008-06-30)

参考文献数

16

被引用文献数

21 24

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We studied age, growth, and maturity of the oceanic whitetip shark Carcharhinus longimanus in the North Pacific, and the reproduction in the North and South Pacific, captured with tuna longline from Nov. 1967 to Oct. 1995. Vertebral rings were examined from 111 males (precaudal length: 54-172cm) and 114 females (precaudal length: 50-195cm). Minimum and maximum numbers of translucent rings were 0 and 11. Marginal increment analysis suggested annualus deposition occurs during spring. A growth difference between sexes was not found. A von Bertalanfly growth equation combining both sexes was as follows; Lt=244.58×{1-e-0.103×(t+2.698)}Lt was expressed as precaudal length in cm at age t. The reproductive condition was examined from 136 males and 85 females. Maturation was determined to be when precaudal length was between 125 and 135cm for both sexes (4-5 years). The parturition period is extended over a long duration. The birth size was 45-55cm and litter size varied from 1-14 with a mean of approximately six in the North Pacific.

著者

Masataka Satomi Bon Kimura Gen Takahashi Tateo Fujii

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.63, no.6, pp.1019-1023, 1997 (Released:2008-06-30)

参考文献数

27

被引用文献数

7 9

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Microbial population in kusaya gravy from Niijima Island was analyzed by grouping of functional characteristics and genetic identification from 16 S rRNA genes (16 S rDNA). Viable conunts in TSSY medium supplemented with 0.1% thioglycolate and 0.3% agar using the MPN method were determined as 1011/ml, which was the highest value compared with previous reports on kusaya gravy. Each of denitrifying, nitrate reducers, sulfate reducers and proteolytic bacteria were estimated as about 109/ml, and starch hydrolyzing and lactic acid producing bacteria were estimated as lessthan 103/ml. Viable counts on TSA medium, which were superior to BPG and B6P6G media, were 108 CFU/ml. The 16 S rDNA were amplified from kusaya gravy by PCR without cultivation of baceria, cloned, and sequenced. Sequence analysis of the cloned partial 16 S rDNA indicated that the major bacteria in kusaya gravy were Bacteroides-Cytophaga group bacteria, wall-less spirochaeta-like bacteria, unidentified bacteria, and so on. The results of genetic identification did not coincide with those of cultural methods; i.e., most of the above bacteria have not been isolated by plate methods so far, and Corynebacterium and Peptococcuceae which were representative organisms in the plate surface method under aerobic or anaerobic conditions, respectively, were not detected by the PCR method. These results indicated that there are diverse organisms which are unknown and unculturable in kusaya gravy.

著者

Takuya Otani Tohru Takahashi Shuhei Matsuura

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.62, no.5, pp.670-674, 1996 (Released:2008-06-30)

参考文献数

20

被引用文献数

6 5

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Larvae of the swimming pea crab Tritodynamia horvathi hatched in the laboratory were reared to adult, and were bred successfully. Zoeal larvae were obtained from ovigerous females collected at Yatsushiro Sound, and they were reared on rotifers, Artemia nauplii and artificial diet. Zoeae hatched in April passed through five zoeal stages during 15-22 days, and the duration of the megalopal stage was 5-11 days. First stage crabs reached the fifth crab stage within two months. Ovigerous females first appeared from September 14, 6 days after the first copulation was observed. However, the percentage of ovigerous females over this period was less than 7%. Copulation and ovigerous females were not detected during November to January. After February 8, copulation resumed and ovigerous females appeared again. The percentage of ovigerous females in the latter breeding season reached 78%. When the crabs were swimming in the aquarium, they were constantly moving their maxillipeds in a regular pattern, and fed on Artemia nauplii or powder of pellets. This suggests that the swimming behavior of T. horvathi is not apeculiar behavior restricted to mating as the copulatory swimming recorded in some other pinnotherids, but a behavior for feeding.

著者

NAOHIKO WATANUKI GUNZO KAWAMURA SHOHEI KANEUCHI TORU IWASHITA

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.66, no.3, pp.417-423, 2000 (Released:2009-03-31)

参考文献数

21

被引用文献数

21

---

The role of vision in the entry of the cuttlefish Sepia esculenta into basket traps was examined in laboratory experiments and by histological examination of the retina. Both entry into the trap and feeding on shore crabs stopped when the tank was completely darkened. The eyes of cuttlefish have a high sensitivity to light. The visual field of cuttlefish was determined by the optical method, based on the assumption that incident light on the pupil from any direction reaches the retina through a refractive lens. The uniocular visual field was found to be 253° on the horizontal plane, and the anterior and posterior binocular visual fields were 86° and 60° respectively. On the retina, areas with especially high visual cell density formed a visual equator slightly above the optical equator. The distribution of the visual cell density indicates no specific visual axis. The visual acuity is 0.36 when estimated from the bait recognition distance and the size of bait during feeding, and 0.89 when determined from the visual cell density at the visual equator and the focal length of the lens. Cuttlefish have far superior visual acuity than fish.

著者

HIROKAZU MATSUDA TAISUKE TAKENOUCHI TAKASHI YAMAKAWA

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.69, no.1, pp.124-130, 2003 (Released:2009-03-31)

参考文献数

23

被引用文献数

14

---

The timing of molting and metamorphosis was monitored for Panulirus japonicus phyllosoma larvae cultured in the laboratory. Larvae cultured under natural light-dark cycle molted synchronously within approximately 1.0 h before and after sunrise, except for a short period after hatching; the timing of molting changed with time of sunrise. When three artificial light-dark cycles were introduced, larvae molted around the start of lighting, irrespective of the light-dark cycles. In the event of a sudden change in the start or end of lighting, molting was regulated by an endogenous rhythm. The start of lighting had a greater impact on the timing of molting than the end of lighting, suggesting that sunrise is probably the critical signal for phase-setting in molting rhythm. Metamorphosis to the puerulus stage occurred within 0.4 h before and 1.2 h after sunset under a natural light-dark cycle, and the timing of metamorphosis was also changed artificially by regulating the end of lighting.

著者

KATSUYUKI HAMASAKI HIDEYUKI IMAI NOBUHIKO AKIYAMA KYOHEI FUKUNAGA

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.70, no.6, pp.988-995, 2004 (Released:2009-03-31)

参考文献数

22

被引用文献数

26

---

Females of the swimming crab Portunus trituberculatus were cultured under natural temperature and high temperature (21°C) conditions to examine ovarian development and oviposition from autumn (October) to the beginning of breeding season in the following spring (May). Ovaries developed because of vitellogenesis of oocytes from October to December and their developmental state did not change during the overwintering period from December to March. In spring, from late March to mid May, some ovaries reached prematuration and maturation stages and ovipositions began from mid-late April under natural temperature conditions. Females reared in tanks of high temperature regimes oviposited earlier than those reared in tanks of natural temperatures. The number of days to oviposition tended to decrease with advancement of the beginning times (early February to late April) of culture of females under high temperature regimes; induced ovipositions were achieved more easily with increasing photoperiod from c. 12 h in early February to c. 14 h in late April. Therefore, it is inferred that the temperature and photoperiod are important environmental factors controlling ovarian development and oviposition.

著者

Fukuda Yuuki Ando Yasuhiro

出版者

Japanese Society of Fisheries Science

雑誌

Fisheries Science (ISSN:09199268)

巻号頁・発行日

vol.77, no.5, pp.875-882, 2011-09

被引用文献数

4

---

Fatty acid analysis of roughscale sole Clidoderma asperrimum flesh lipids was carried out by gas chromatography. An unidentified peak appeared in the chromatogram in the elution region of ≥C24 fatty acids. After enrichment by solvent partitioning, reversed-phase thin-layer chromatography (TLC), and argentation TLC, the peak component was subjected to structural analyses. The partially hydrogenated products after reaction with hydrazine hydrate gave seven isomers of cis-hexacosenoic acid (26:1). Gas chromatography-mass spectrometry (GC–MS) analyses of their dimethyl disulfide adducts identified the monounsaturates as 5-, 8-, 11-, 14-, 17-, 20-, and 23-26:1. The peak component was assigned to all-cis-5,8,11,14,17,20,23-hexacosaheptaenoic acid (26:7n-3). GC–MS analyses of the 4,4-dimethyloxazoline derivative and methyl ester confirmed this structure. This fatty acid is a rare, very long-chain polyunsaturated fatty acid (VLCPUFA). The concentrations of the acid found in roughscale sole were 0.69 ± 0.34% (N = 5) of total fatty acids in flesh lipids. Roughscale sole appears to be characterized by the occurrence of 26:7n-3, which is lacking in popular sources of methylene-interrupted VLCPUFA, such as vertebrate retina, spermatozoa, and herring.

著者

Matsuura Hiroshi Yazaki Ikuko Okino Tatsufumi

出版者

Springer Japan

雑誌

Fisheries Science (ISSN:09199268)

巻号頁・発行日

vol.75, no.3, pp.777-783, 2009-05

被引用文献数

25

---

Larval metamorphosis inducers of the sea cucumber Apostichopus japonicus were screened from physiologically active compounds. Doliolaria larvae completed their metamorphosis to juveniles in 120 hours when treated with 5-10 μM of dopamine and L-DOPA, and 50 μM of L-adrenaline and L-noradrenaline. Doliolaria larvae had to be exposed to dopamine or L-DOPA for at least 24 h. D1-like dopamine receptor antagonists SKF87566 and LE300 (10 μM) inhibited metamorphosis by dopamine. However, the D2-like dopamine receptor antagonists sulpiride and nemonapride (10 μM) did not inhibit the effect of dopamine. The results suggest that D1-like dopamine receptors are involved in larval metamorphosis of the sea cucumber A. japonicus.

著者

SEINEN CHOW PAUL A SANDIFER

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.67, no.2, pp.370-372, 2001 (Released:2009-03-31)

参考文献数

13

被引用文献数

3

著者

YASUNORI ISHIBASHI HIDEAKI EKAWA HACHIRO HIRATA HIDEMI KUMAI

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.68, no.6, pp.1374-1383, 2002 (Released:2009-03-31)

参考文献数

50

被引用文献数

50

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Nile tilapia were exposed to severe hypoxic conditions. The respiratory frequency (RF) of the fish reached a maximum level at approximately 10 mmHg PO2 and decreased gradually thereafter. The fish sank to the bottom and subsequently their respiration began to stop. The hypoxic conditions increased the hematocrit value. As RF decreased, plasma cortisol and glucose levels climbed drastically. Just before respiratory arrest, the ATP and the total adenylate (TA) concentrations were significantly depressed in the liver, kidney and ordinary muscle but not in the heart or gill. As RF decreased, ATP and TA in both the liver and kidney decreased rapidly. Cytochrome oxidase activity increased significantly in the brain, heart, gill and ordinary muscle until respiratory frequency peaked. However, from the peak RF, this activity decreased in the liver and kidney. Lactic acid levels in both ordinary muscle and liver increased markedly when the fish sank. These results indicate that the stress response to hypoxic conditions is induced markedly with the decreased RF. It is also suggested that the decreased energy status in the liver and kidney of tilapia occurs at the same stage as the metabolic depression in the whole body, without increases in the aerobic and anaerobic metabolisms.

著者

CHOU CHIU-LONG PAON LISA ANN MOFFATT JOHN DANIEL ZWICKER BLAINE

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.69, no.2, pp.369-378, 2003

被引用文献数

7

---

Bioaccumulation and distribution of Mn and Zn in the total soft tissues, digestive glands, residuals and adductor muscles of the horse mussel <i>Modiolus modiolus</i> from three sites, including industrialized and non-industrialized locations in Eastern Canada, were investigated. Extremely high digestive gland metal concentrations were found in individual mussels, as high as 1819 μg/g Mn wet weight and 1964 μg/g Zn wet weight, with mean values from 358 to 404 μg/g Mn and from 399 to 614 μg/g Zn for the collection sites. High Mn to Zn interrelationships were observed inall types of tissues and at all sites. Between different tissues, Zn was interrelated by linear relationships, and Mn was best described by power curve relationships for all tissue types. In the total soft tissue, Mn and Zn interrelations were fitted to power regression curves with different slopes between the three study sites. This indicated that horse mussel was exposed to different metal levels inthe environments and could be useful for monitoring these metals. The uptake of both metals at extremely high concentrations, the lack of regulation and the occurrence of interactions all suggest that Mn and Zn may play a biological role in horse mussels. Zn and Mn interactions, surprisingly, were not disrupted at the very high concentrations of either metal, which proves that the mechanism of metal interactions does not involve a detoxification role.

著者

KOICHI SASAKI MAKOTO KUDO TAKESHI TOMIYAMA KINUKO ITO MICHIO OMORI

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.68, no.1, pp.104-116, 2002 (Released:2009-03-31)

参考文献数

13

被引用文献数

19

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The predation pressure on the siphons of the bivalve Nuttallia olivacea by the juvenile stone flounder Platichthys bicoloratus in the Natori River estuary, Miyagi, was estimated from both sides of the predator-prey relationship to analyze the specific relationship in which predators remove a part of the prey. Feeding experiments determined the feeding rate required to achieve the growth of juvenile stone flounders in the field. A juvenile cropped siphon tips at a mean of 56 per day from March to early July. The siphon tips that a juvenile consumed in a season amounted to 6375 pieces (6.2 g). In terms of predation, the duration since the last cropping in the field from the regeneration of cropped siphons was analyzed. The mean cropping rate of 0.211 times a day per clam in an area of intensive predation indicated that a clam was cropped 25.8 times (22.1 mg) in a season by fishes. The mean cropping rate by juvenile stone flounders was estimated to be 0.160 times a day. Of the 25.8 croppings, 19.5 (16.9 of the 22.1 mg) could be attributed to juvenile stone flounders. The results proved that a juvenile stone flounder preyed on approximately 370 clams in a season.

著者

HACHIRO HIRATA

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.68, no.sup1, pp.829-834, 2002 (Released:2008-06-30)

参考文献数

24

被引用文献数

1

---

The harmonization between aquaculture developments and the conservation of aquatic environments is the key to sustaining aquaculture. One of the obstacles to this harmonization is the negative economic relationship between developments and conservation. In order to sustain a systematic aquaculture, we need to establish benefits for both the human economy and the biological economy. The polyculture of Ulva and fish has been conducted by our group since 1964, with differing intents. Sakai was able to develop an abalone culture that fed on the Ulva cultured in the fish farm, and these mollusks produced green pearls as a byproduct of this fish culture. In that way, human profit was harmonized with the biological economy. The whole aqua-crop ensilage (WACE) system has been lectured by Hirata since 1999. The fish culture introduces nutrients into the sea. The nutrients contribute to the growth of sessile organisms. Whole organisms are harvested and ensilaged to produce the probiotic feed. This feed is mixed with routine fish feed. Ruminated culture will also be applied for byproducing the rotifer in culture of fish. These systems will be developed in the future.

著者

Kazumi Sakuramoto

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.61, no.3, pp.401-405, 1995 (Released:2008-06-30)

参考文献数

16

被引用文献数

5

---

A method is presented to estimate relative recruitment from catch-at-age data alone by applying fuzzy control theory. An important feature of this approach is that the natural mortality coefficient is not needed. Simulation tests were conducted to determine the performance of this approach including comparison with a conventional method. The simulations showed that the assumed trend of recruitment was well reproduced. The fuzzy method possessed a higher robustness to noise in the catch-at-age data than the conventional method. This approach is useful for the analysis of catch-at-age data.

著者

Okumura Sei-ichi Arai Katsutoshi Harigaya Yoshitaka Eguchi Hirotaka Sakai Mizuho Senbokuya Hiroaki Furukawa Suehiro Yamamori Kunio

出版者

Japanese Society of Fisheries Science

雑誌

Fisheries Science (ISSN:09199268)

巻号頁・発行日

vol.73, no.2, pp.237-243, 2007

被引用文献数

11

著者

Awano Shinichi Miyamoto Koji Hosokawa Masashi Mankura Mitsumasa Takahashi Koretaro

出版者

Japanese Society of Fisheries Science

雑誌

Fisheries Science (ISSN:09199268)

巻号頁・発行日

vol.72, pp.909-912, 2006

被引用文献数

11