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 5

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
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
3

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
18

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
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
34

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
6

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
14

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.