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981.
Masashi Ando Shintaro Mizuochi Yasuyuki Tsukamasa Ken -Ichi Kawasaki 《Fisheries Science》2007,73(3):705-712
ABSTRACT: Changes in meat firmness and structure of cultured yellowtail at several storage temperatures, from −1.5°C to 10°C, were compared. Firmness decreased less at −1.5°C and 10°C than at the other temperatures. During storage at temperatures from −0.5 to 4.0°C, expansion of intercellular space, which indicates weakening of the connecting force between muscle cells, began to increase after 8 h storage, and the ratio of space to the whole area increased by 3.4–4.9 times after 24 h of storage. However, at −1.5°C and 10°C, the increase of intercellular space was suppressed, and the ratio was 2.4–2.6 times, even after 24 h storage. Collagen fibrils connecting muscle cells disintegrated after 24 h storage at all storage temperatures. Conversely, in 10°C storage, the fine structure of muscle, except for collagen fibrils, was maintained better than at other storage temperatures. These findings indicate that −1.5 and 10°C storage could maintain fish-meat quality for longer periods than storage at −0.5, 1.0, or 4.0°C, the normal refrigeration temperature. 相似文献
982.
Wataru Doi Than Than Lwin Masashi Yokota Carlos Augusto Strüssmann Seiichi Watanabe 《Fisheries Science》2007,73(2):331-340
ABSTRACT: Sexual maturity, morphological sexual dimorphism, and reproduction of the goneplacid crab Carcinoplax vestita were investigated in Tokyo Bay, Japan, from November 2002 to October 2003. The puberty molt in males was evidenced by changes in the relative size of the chelipeds and merus of the walking legs, and was estimated to occur at a size range of 13.20–18.85 mm carapace length. Post-pubertal females were identified by the relative size of the abdomen and puberty was estimated to occur at a size range of 12.81–15.46 mm carapace length. Sexual dimorphism in C. vestita was observed in all features that showed secondary sexual characteristics. Monthly changes of gonad index in males, and of seminal receptacle index and occurrence of sperm plugs in females were synchronized, and indicated that mating was intense in spring. Ovaries began developing in March. Ovigerous females were found in all months except December, but were clearly more abundant between August and October. Fecundity ranged from 7800 to 57 000 mature oocytes per female per batch and was highly correlated with body size. The results suggest that some females may spawn more than one batch per year. 相似文献
983.
Noriyuki Takai Noriyuki Hirose Takuya Osawa Kazuyuki Hagiwara Takahito Kojima Yuji Okazaki Tomohiro Kuwae Toru Taniuchi Kiyoshi Yoshihara 《Fisheries Science》2007,73(3):593-608
ABSTRACT: It is important to clarify trophic dynamics in marine ecosystems for management of the fishing ground. Organic carbon sources and trophic position of pelagic fishes in the coastal waters of the south-eastern Izu Peninsula, Japan, were examined on the basis of carbon and nitrogen stable isotope distributions. The δ13 C of the fishes was mostly distributed from −19 to −16‰ for nektonic fishes (13 species of adults and immatures) and planktonic fishes (10 species of larvae and juveniles), close to the δ13 C values of particulate organic matter and planktonic decapods. These δ13 C signatures for the inhabitants of the water column were in contrast with the high δ13 C values (mainly −16 to −13‰) for demersal fishes of Scorpaeniformes and benthic polychaetes collected in the surf zone. These results indicate that nektonic and planktonic fishes depend on phytoplankton for carbon supply. The δ15 N signatures suggest that the trophic position ranged 3.1–4.5 for the nektonic fishes and 2.9–3.7 for the planktonic fishes, premised on trophic level 3 for larval Japanese anchovy Engraulis japonicus . Thus, planktivorous fishes should be mainly assigned to trophic levels 3 and 4 in this area. 相似文献
984.
Tsutomu Hattori Yoji Narimatsu Masaki Ito Yuji Ueda Kunihiro Fujiwara Daiji Kitagawa 《Fisheries Science》2007,73(2):341-347
ABSTRACT: The biomass of bighand thornyhead Sebastolobus macrochir was increased by the high recruitment success of the 1999–2002 year classes off the Pacific coast of northern Honshu, Japan. In this study, the growth of bighand thornyhead was examined over a 9-year period from 1996 to 2004 in this area. The growth of the 1999 year class and the 2000–2002 year classes was reduced at 3 and 2 years old, respectively, while the 1999–2002 year classes were smaller than the 1993–1998 year classes. In 2-, 3- and 4-year-old fish, the relationship between abundance and mean standard length was expressed by negative linear regressions, while fish became smaller when abundance of the year class was larger. Mean bottom temperatures were stable at depths of 350–900 m; variations in water temperature were small in the main distribution area of bighand thornyhead. We discuss the factors affecting the growth of bighand thornyhead via changes in the demersal fish community and feeding habits. 相似文献
985.
The ability to discriminate local stocks of Japanese anchovy Engraulis japonicus was assessed based on data from four elements (K, Na, P, and Sr) using an electron probe micro analyzer (EPMA) and data from
three elements (Ba, Mn, and Sr) using inductively coupled plasma mass spectrometry (ICP-MS) from the otoliths of 40 anchovy
(23.6–47.0 mm body length). Anchovy were caught at three sites (Aki-nada, Hiuchi-nada, and Osaka Bay) in the Seto Inland Sea,
and one site (Kuroshio extension) in the Pacific Ocean in 2002. In order to discriminate different spawning grounds, EPMA
data from the core portion (from core to 30 μm in the core-posterior axis) were used. Results showed that it was difficult
to discriminate between the Seto Inland Sea and the Pacific anchovy by EPMA data. Conversely, it was possible to discriminate
between the Seto Inland Sea and the Pacific anchovy by ICP-MS data from bulk otoliths. Our results showed that Mn contents
of otoliths using ICP-MS discriminate between spawning grounds most, and Ba and Sr discriminate less. The difference in elemental
compositions in anchovy otoliths between the Seto Inland Sea and the Pacific Ocean might be reflected by cumulative experienced
elemental composition of ambient sea water during life history between the Seto Inland Sea and the Pacific anchovy. 相似文献
986.
Masatomi Hosoi Chuya Shinzato Masaya Takagi Shoko Hosoi-Tanabe Hideki Sawada Eri Terasawa Haruhiko Toyohara 《Fisheries Science》2007,73(2):385-394
ABSTRACT: Taurine is the primary osmolyte in marine molluscs, whose cellular osmo-conforming process is vital for environmental adaptation because of a lack of osmotic homeostasis. Here, cDNA cloning and expression, and functional analyses of taurine transporter (TAUT) from the giant Pacific oyster are reported on. The deduced amino-acid sequence of oyster TAUT (oyTAUT) showed 47–51% identity to those of vertebrate TAUT, whereas identity among the vertebrates is 78–95%. Functional analysis of oyTAUT expressed in Xenopus oocytes revealed that oyTAUT has a lower affinity and specificity for taurine and a requirement for higher NaCl concentration, compared with vertebrate TAUT. Taken together with similar functional properties of TAUT from mussel, indicated by our previous study, it is possible that these functional features reflect the internal environment of the molluscs (i.e. higher taurine and NaCl concentrations). Oyster taurine transporter mRNA expression was induced by not only hyper-osmotic stress, similar to other TAUT, but also hypo-osmotic stress. It is speculated that the expression in response to hypo-osmotic stress was induced by a substantial decrease in tissue taurine content following the decrease in the internal osmolality. 相似文献
987.
Increased abundances of a number of seabird species have been found in areas of mussel longline aquaculture (compared to control
sites) in a recent study at Bantry Bay, southwest Ireland. The aim of this study was to investigate whether this form of mussel
aquaculture also affects the activity budgets and foraging behaviour of these seabirds. Scan-sampling was used to compare
seabird activity budgets between three areas of mussel longline aquaculture and three control sites. Foraging activities of
Great-Northern Divers Gavia immer, an Annex 1 species under the Euopean Union's Birds Directive, were also compared between sites using focal sampling. The
behaviour of gulls (Larus sp.), Cormorants Phalacrocorax carbo, Shags Phalacrocorax aristotelis and Great-Northern Divers (but not auks, Alcidae) differed significantly between areas of mussel aquaculture and control
sites in this study. Mussel suspension buoys were heavily utilized by gulls, cormorants and shags as safe perching platforms
for preening activities. Gulls also fed extensively on epifauna attached to the buoys. Great-Northern Divers spent more time
snorkelling (head submerged in search of food) in mussel sites than in the control sites, however dive duration and visible
foraging success rates did not differ significantly between sites. Overall, the environmental impact of mussel suspension
culture appears to be positive or neutral on marine bird species occurring at this study site. 相似文献
988.
989.
Shoshi Mizuta Yuko Nakanishi Masashi Shiraishi Yoshihiro Yokoyama Reiji Yoshinaka 《Fisheries Science》2007,73(6):1353-1361
ABSTRACT: To obtain fundamental information for the effective use of scallop Patinopecten yessoensis mantle, which is one of the underutilized marine resources. Some properties of collagen contained in the mantle were examined by chemical and histochemical techniques. Collagen content in the mantle varied annually, ranging from 0.98 to 1.72% of wet tissue, 7.7 to 12.6% of dry tissue and 13.5 to 26.5% of total protein, being relatively in high level of collagen content of invertebrate muscles. Collagen fiber was densely distributed in the inner connective tissue matrix of the mantle pallial, in contrast to the inner fold part which was rich in muscle fibers. The collagen contained in the crude collagen fraction (residue after alkali extraction), prepared from the mantle, was revealed to have considerably low solubility on hot-water extraction, constantly less than 20% of the total collagen at the temperatures in the range of 20–90°C. 相似文献
990.