Estimating the spawning season of black sea bream Acanthopagrus schlegelii in Hiroshima Bay,Japan, from temporal variation in egg density     

Kawai  Kentaro  Fujita  Hiroki  Sanchez  Gustavo  Furusawa  Shuichi  Umino  Tetsuya 《Fisheries Science》2020,86(4):645-653

Fisheries Science - We aimed to determine the spawning period of black sea bream Acanthopagrus schlegelii in Hiroshima Bay, Japan, based on the distribution of its eggs, to assist in the resource...  相似文献   

Effect of tributyltin oxide exposure on the F<Subscript>0</Subscript> and F<Subscript>1</Subscript> generations of a marine teleost,the mummichog <Emphasis Type="Italic">Fundulus heteroclitus</Emphasis>     

Kazuhiko Mochida  Katsutoshi Ito  Kumiko Kono  Toshimitsu Onduka  Akira Kakuno  Kazunori Fujii 《Fisheries Science》2010,76(2):333-341

The effects of organotin compounds on marine organisms, especially on their reproduction, are a continuing source of concern. We performed full-life-cycle exposure tests of tributyltin oxide (TBTO) at sub-lethal concentrations (0.13, 0.25, 0.5 and 1.0 μg/l) using a marine fish, the mummichog Fundulus heteroclitus, and studied the toxic effects of exposure to TBTO at various life-cycle stages of the fish. The effect of TBTO was initially studied on sex differentiation and then on spermatogenesis in maturing fish. A mating experiment was performed to determine the effects of exposure on the fecundity of female fish, fertilization success, and the hatch of the F₁ generation. In all experimental groups, TBTO exposure resulted in a tendency toward a male-biased sex ratio and caused a significant increase in the frequency at which apoptotic cells appeared in the testes. Exposure to 1.0 μg/l TBTO resulted in a significant decrease in fecundity, but no significant effect was found on the fertilization ratio. Time to hatch and hatchability of the F₁ generation were markedly affected in some exposure groups. These results indicate that long-term exposure of the mummichog to TBTO affects not only gonadal sex differentiation and spermatogenesis but also spawning and egg quality.  相似文献   

Purification and characteristics of trypsin from masu salmon (<Emphasis Type="Italic">Oncorhynchus masou</Emphasis>) cultured in fresh-water     

Gaku Kanno  Takahito Yamaguchi  Hideki Kishimura  Etsurou Yamaha  Hiroki Saeki 《Fish physiology and biochemistry》2010,36(3):637-645

Trypsin from the pyloric ceca of masu salmon (Oncorhynchus masou) cultured in fresh water was purified by a series of chromatographies including Sephacryl S-200, Sephadex G-50 and diethylaminoethyl cellulose to obtain a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE) and native PAGE. The molecular mass of the purified trypsin was estimated to be approximately 24,000 Da by SDS–PAGE. The enzyme activity was strongly inhibited by phenylmethylsulfonyl fluoride, soybean trypsin inhibitor, and N ^α -p-tosyl-l-lysine chloromethyl ketone. Masu salmon trypsin was stabilized by calcium ion. The optimum pH of the masu salmon trypsin was around pH 8.5, and the trypsin was unstable below pH 5.0. The optimum temperature of the masu salmon trypsin was around 60°C, and the trypsin was stable below 50°C, like temperate-zone and tropical-zone fish trypsins. The N-terminal 20 amino acid sequence of the masu salmon trypsin was IVGGYECKAYSQPHQVSLNS, and its charged amino acid content was lower than those of trypsins from frigid-zone fish and similar to those of trypsins from temperate-zone and tropical-zone fish. In the phylogenetic tree, the masu salmon trypsin was classified into the group of the temperate-zone fish trypsin.  相似文献   

Density and sound-speed contrasts,and target strength of Japanese sandeel <Emphasis Type="Italic">Ammodytes personatus</Emphasis>     

Hiroki Yasuma  Ryo Nakagawa  Takashi Yamakawa  Kazushi Miyashita  Ichiro Aoki 《Fisheries Science》2009,75(3):545-552

Sound-speed and density contrasts (h and g, respectively), important acoustic material properties, of Japanese sandeel Ammodytes personatus were measured to estimate theoretical target strength (TS). The measured sound-speed contrast of adult fish varied between 1.016 and 1.023 (mean 1.020), and showed temperature dependence. The measured density contrast differed significantly between juvenile and adult. The density contrast of juvenile varied between 1.017 and 1.024 (1.021), and that of adult varied between 1.026 and 1.038 (1.032). Using these results, TS at 38 and 120 kHz in the fishing season were estimated by an empirical sound scattering model. TS of an individual fish varied significantly with change of tilt angle. TS of near-dorsal aspect (TS_max) and tilt-averaged TS (TS_ave) differed by up to 7 dB. At both frequencies, two different TS_ave−length relationships (TS_ave = a log L + b) were obtained for adult and juvenile. The coefficients of log L of adult were close to 20, suggesting that backscattering strength was proportional to square of body length. These values were larger in juvenile (34.0 at 120 kHz, 56.5 at 38 kHz), suggesting that backscattering strength varied drastically with the cube or fifth power of body length.  相似文献   

PCR-RFLP genotypes associated with quinolone resistance in isolates of Flavobacterium psychrophilum     

Izumi S  Ouchi S  Kuge T  Arai H  Mito T  Fujii H  Aranishi F  Shimizu A 《Journal of fish diseases》2007,30(3):141-147

A novel genotyping method for epizootiological studies of bacterial cold-water disease caused by Flavobacterium psychrophilum and associated with quinolone resistance was developed. Polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) was performed on 244 F. psychrophilum isolates from various fish species. PCR was performed with primer pair GYRA-FP1F and GYRA-FP1R amplifying the A subunit of the DNA gyrase (GyrA) gene, which contained the quinolone resistance determining region. Digestion of PCR products with the restriction enzyme Mph1103I showed two genotypes, QR and QS. The difference between these genotypes was amino acid substitutions at position 83 of GyrA (Escherichia coli numbering). The genotype QR indicated an alanine residue at this position associated with quinolone resistance in F. psychrophilum isolates. Of the 244 isolates tested in this study, the number of QR genotype isolates was 153 (62.7%). In isolates from ayu (n=177), 146 (82.5%) were genotype QR. With combination of this technique and previously reported PCR-RFLP genotyping, eight genotypes were observed in F. psychrophilum isolates. Using this genotyping system, the relationships between genotype and host fish species, or locality of isolation, were analysed and are discussed.  相似文献   

Evaluation of the temperature and relative humidity preferences of the western dry-wood termite <Emphasis Type="Italic">Incisitermes minor</Emphasis> (Hagen) using acoustic emission (AE) monitoring     

Yuliati Indrayani  Tsuyoshi Yoshimura  Yoshiyuki Yanase  Yoshihisa Fujii  Yuji Imamura 《Journal of Wood Science》2007,53(1):76-79

Twenty-four different combinations of six temperatures (15°, 20°, 25°, 30°, 35°, and 40°C) and four relative humidity (RH) (60%, 70%, 80%, and 90%) conditions were used for pseudergates of the western dry-wood termite Incisitermes minor (Hagen). The feeding activities of the termites were monitored by the detection of generated acoustic emission (AE) events from feeder wood blocks in a test chamber. Temperature and RH showed independent and interactive significant effects on the feeding activity of I. minor. The optimal temperature and RH conditions for the feeding activities were 35°C and 70%, respectively, and the optimal combinations were 35°C-70% and 35°C-80% with an exceptionally higher feeding activity at the combination condition of 30°C-70%.  相似文献   

低分子量热激蛋白Bmhsp19.9基因的表达   总被引：1，自引：0，他引：1  

李斌  夏庆友  藤井博  伴野丰  鲁成 《农业生物技术学报》2005,13(2):195-201

利用RT-PCR技术，对家蚕(Bombyx moil)低分子量热激蛋白Bmhsp19．9基因进行了定量表达分析。Bmhsp19．9在各组织中均有一定量的表达，但不同组织间的表达差异达10多倍，表达量丰富的组织是生长发育旺盛的组织，如精巢和卵巢，然后是丝腺、蛹等组织。其应激表达模式可分为3类，以其在精巢、后部丝腺和脂肪体中的强应激表达模式为主，经热刺激处理后其表达量有显著增加。经刺激诱导2h后其表达量达到最高，随后逐渐降低，在热刺激诱导12h后是未刺激的2～3倍，而此时Bmhsp19．9在脂肪体中的应激表达是其对照的10多倍。根据Bmhsp19．9在不同组织中的基本表达量、应激表达量和应激表达的持续时间各不相同，显示其与细胞分裂与分化等生命活动有一定联系。并认为其在后部丝腺、脂肪体、精巢、卵巢与血液中作用方式不一样，推测其作为分子伴侣在组织间的作用对象与作用效应也应有所差异。  相似文献   

Role of sorbitol in manufacturing dried seafood from heated squid meat     

Tomokazu Kubo  Hiroki Saeki 《Fisheries Science》2001,67(3):524-529

SUMMARY: Japanese common squid meat was heat-treated at 80°C for 1 min, cured with 1.0 M sorbitol solution (pH 7.0) at 4°C for 18 h, and dried further at 30°C (60% relative humidity) for 16 h. Osmotic dehydration during the sorbitol curing process and slow moisture vaporization at the initial drying period were observed regardless of the heat denaturation of muscle protein. Simultaneously, lowering the amount of moisture vaporized in the falling rate of the drying period caused a shortening of the total drying time. Furthermore, the shear force of the dried product from heat-treated meat was kept at a lower value by sorbitol curing, although the suppression effect of sorbitol on the hardening of dried meat was lost by protein denaturation. These results are useful for understanding the role of sorbitol in reducing drying time and in eliminating excess hardening of dried squid products.  相似文献   

Pharmacological studies on doping drugs for race horses. 1. Trans-pai-oxocamphor     

S Fujii  S Inada  S Yoshida  C Kusanagi  K Mima 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1970,32(6):307-317

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Seroprevalence of Neospora caninum in female water buffaloes (Bubalus bubalis) from the southeastern region of Brazil     

Fujii TU  Kasai N  Nishi SM  Dubey JP  Gennari SM 《Veterinary parasitology》2001,99(4):331-334

Antibodies to Neospora caninum were assayed in sera of 222 female water buffaloes from Ribeira Valley of S?o Paulo State, Brazil, using an indirect fluorescent antibody test (IFAT) and Neospora agglutination test (NAT). IFAT antibodies were found in 64% of buffaloes with titers of 1:25 (42 buffaloes), 1:50 (53 buffaloes), 1:100 (31 buffaloes), 1:200 (10 buffaloes), 1:400 (3 buffaloes), or > or =1:800 (3 buffaloes). NAT antibodies were found in 53% of buffaloes; in titers of 1:40 in 52 buffaloes, 1:80 in 27 buffaloes, 1:160 in 21 buffaloes, and > or =1:320 in 17 buffaloes. Results indicate a high prevalence of N. caninum exposure in water buffaloes in Brazil and warrant an investigation of the role of N. caninum as an abortifacient in water buffaloes.  相似文献