共查询到20条相似文献,搜索用时 31 毫秒
1.
J. W. Huang L. X. Tian Z. Y. Du H. J. Yang Y. J. Liu 《Fish physiology and biochemistry》2007,33(2):167-172
This study was conducted to evaluate the effects of dietary thiamin on the physiological status of the juvenile grouper, Epinephelus coioides. Graded levels of thiamin (0.08, 0.50, 2.12, 3.15, 4.63, 12.37 mg thiamin kg−1 diet) were fed to grouper juveniles (mean weight: 16.97 ± 0.14 g) for 10 weeks. Although fish fed the thiamin-deficient (TD)
diet showed no obvious symptoms of thiamin deficiency or increased mortality, those fed the lowest doses of thiamin (0.08
and 0.50 mg thiamin kg−1 diet) had significantly decreased transketolase activity in the liver. In addition, the level of liver thiobarbituric acid
reactive substances in fish fed the TD diet was 33–67% higher than that in fish with the thiamin-supplemented diet. There
were no significant differences in superoxide dismutase activity between the different groups of fish. 相似文献
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MICHAEL BAUMANN 《Fisheries Oceanography》1998,7(1):63-65
In this paper I discuss some of the shortcomings of today's marine science in response to a recently published paper by Ann Gargett (1997). Three problem areas have been identified in the field linking climate forcing and fish production: First, the yet-to-be established observational proof for a relationship between the two; Second, the strongly neglected biology of organisms at evolutionary and ecological time scales; and thrird, the disregard for spatial and temporal scales in the discussion of mechanisms and supporting data. 相似文献
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The growth hormone (GH) gene isolated and cloned from various Labeo species (L. rohita, L. calbasu, L. fimbriatus, L. gonius, L. bata, and L. kontius) is shown to contain a single copy in the haploid genome, with an overall size of ∼2.5 kb. The GH gene in all the Labeo species studied has five exons and four introns of various sizes with the exon/intron boundary sequence of GT/AG. The length
variation of the GH gene between the species is found to be due to length variation in the form of several deletions in the
third intron. The length of individual exons is the same in all the species with an open reading frame (ORF) of 630 bp (210
amino acids) except in L. rohita, which has a 9 bp deletion in the fourth exon, resulting in a shorter GH of 621 bp (207 amino acids). The similarity in the
nucleotide and amino acid sequences between the different Labeo species is greater than 97%, in spite of eight amino acids being altered in the GH protein of Labeo that reside outside the conserved domain sequence required for its function. Nucleotide substitutions are seen in the form
of 20 transitions and three transversions in the ORF of the GH gene. Both types of transitions (A–G; T–C) and only one type
of transversion (A–C) are detected in the GH gene. Codon preference in GH gene shows a strong preference for G and C in the
wobble position of the codons. Genetic interrelationships determined between Labeo and other species of fishes using nucleotide sequence of GH cDNA supports the overall teleost classification of Nelson (Fishes
of the World. Wiley, New York, 1984) with separate clades for Ostariophysi, Protacanthopterygii, and Acanthopterygii. Besides, the unweighted pair group method
with arithmetic means (UPGMA) analysis clearly distinguishes between the species having five exons and four introns in the
GH gene from the species having six exons and five introns in the same gene. The Labeo species analyzed in the present study could be clustered into two groups using the maximum-parsimony method on the intron
sequences data of the GH gene. 相似文献
7.
R. M. Rico M. T. Tejedor-Junco S. T. Tapia-Paniagua F. J. Alarcón J. M. Mancera F. López-Figueroa M. C. Balebona R. T. Abdala-Díaz M. A. Moriñigo 《Aquaculture International》2016,24(4):965-984
Partial substitutions of fish meal by 5, 15, or 25 % of Gracilaria cornea or Ulva rigida in experimental diets were evaluated to study their effects on biodiversity of intestinal microbiota composition in gilthead seabream (Sparus aurata) juveniles. The diets were offered to duplicate groups of 15 juvenile fish (14.0 ± 0.5 g) for 70 days, and at the end of the experiment the intestinal microbiota from four specimens of each treatment was analysed by denaturing gel gradient electrophoresis. Results showed that the substitution of fish meal by algae meal induced important modifications in the intestinal microbiota community, as a big reduction of the biodiversity when the highest percentage (25 %) of U. rigida was included. On the contrary, an increase on the number of species was detected when a 15 % of algae was included. Various Lactobacillus delbrueckii subspecies were selectively stimulated when G. cornea was included in the feed, and other bacterial species, such as those included in the Vibrio genus, were reduced. 相似文献
8.
H. Qi X. P. Dong L. N. Cong Y. Gao L. Liu T. Mikiro B. W. Zhu 《Fish physiology and biochemistry》2007,33(2):181-188
The sea cucumber (Stichopus japonicus) is able to undergo autolysis in response to a variety of environmental and mechanical cues. Within the framework of a long-term
study of this phenomenon we have purified a protease from the body wall of the sea cucumber by means of ion-exchange chromatography
with DE-52 cellulose and gel filtration chromatography with Sephadex G-100. The final enzyme preparation was nearly homogeneous
on polyacrylamide gel electrophoresis, and its molecular weight was estimated to be approximately 35.5 kDa. The purified enzyme
exhibited a maximum activity for the hydrolysis of casein at pH 7.0 and 50°C and a remarkable stability at pH 4.0–7.0 and
40–60°C. Based on the inhibition and activation profiles obtained with numerous specific protease inhibitors and an activator,
the protease purified from the body wall of the sea cucumber was defined to be a cysteine-like protease. 相似文献
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Spectral sensitivity of the dogfish shark (<Emphasis Type="Italic">Scyliorhinus canicula</Emphasis>)
Z. Gačić I. Damjanović B. Mićković A. Hegediš M. Nikčević 《Fish physiology and biochemistry》2007,33(1):21-27
The action spectrum of the electroretinographic (ERG) b-wave and the unmasked late receptor potential (LRP) were measured
under a variety of conditions (isolated eyecup, detached retina, b-wave recording in fresh preparations, LRP measurements
after low-temperature aging, dark and light adaptation). It was shown that in the dogfish, Scyliorhinus canicula (L.), eyecup spectral sensitivity matched closely the pigment 502 spectral curve like other rhodopsin-possessing marine species.
The ERG b-wave is as good an indicator of spectral sensitivity as the unmasked LRP that directly reflects the responsiveness
of photoreceptors. Differences in spectral sensitivity were not revealed between dogfish preparations studied under a variety
of conditions (isolated eyecup vs. detached retina; b-wave recording in fresh preparations vs. LRP measurements after low-temperature
aging; dark vs. light adaptation). We developed a new model for spectral sensitivity data. 相似文献
11.
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
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Gao Zexia Wang Weimin Yang Yi Khalid Abbas Li Dapeng Zou Guiwei James S. Diana 《Fish physiology and biochemistry》2007,33(3):213-222
The peripheral blood cells of one-year-old Chinese sturgeon (Acipenser sinensis) have been studied by light microscopy and transmission electron microscopy. The erythrocyte count was 84.86 × 104 cell mm−3 in the peripheral blood of the fish and that of leukocytes was 2.24 × 104 cell mm−3. The erythrocytes and four main types of leucocyte—thrombocytes, lymphocytes, granulocytes (including neutrophils and eosinophils),
and monocytes, were identified in the peripheral blood. In addition to normal erythrocytes, reticulocytes and division of
erythrocytes were observed. Thrombocytes were the most numerous among the leukocytes, and the number of neutrophils with lobated
nuclei was larger than for other fish. The structures of the erythrocytes, lymphocytes, monocytes, granulocytes, and thrombocytes
of the fish were studied. The erythrocytes were almost completely devoid of organelles, except for some mitochondria and granules.
A large number of vacuoles and a few organelles were observed in cytoplasm of the monocytes. There were many microvilli on
the membrane and pseudopodia-like cytoplasm bulge in the lymphocytes. The neutrophils were round or oval in shape with bilobed,
trilobed, or multilobed nuclei whereas the eosinophils had big special granules, dark stained. There were many vesicles in
some thrombocytes, which were related to its phagocytosis; some thrombocytes had almost no cytoplasm or organelles. 相似文献
14.
Hiroshi Oikawa Tsuneo Fujita Ken Saito Masataka Satomi Yutaka Yano 《Fisheries Science》2007,73(2):395-403
ABSTRACT: The difference in paralytic shellfish poisoning (PSP) toxin accumulation in the crabs Telmessus acutidens and Charybdis japonica was investigated at Onahama, Fukushima Prefecture, from 2002 to 2005. The level of toxin accumulation in the hepatopancreas of T. acutidens corresponded to that of mussels when examined on a yearly basis. In 2003, some crabs had a high toxicity of approximately 1000 MU, which compares to one-third of the human minimum lethal dose. Therefore T. acutidens should be monitored as a vector species of PSP toxin. The toxin profile of T. acutidens was also investigated. Because an increase in highly toxic species of PSP toxins with a decrease in low toxic species, such as N -sulfocarbamoyl-11-hydroxysulfate toxins, was not clearly observed between consecutive samples, toxin transformation in T. acutidens was considered to have a minimal impact on toxicity. PSP toxins were also detected in several specimens of C. japonica , but the highest toxicity was only 7.4 MU/g in the hepatopancreas. Because C. japonica is widely distributed in the coastal waters of Japan, investigation of toxin accumulation in the crab should be continued, including its investigation in different areas of water from Onahama, where the causative dinoflagellates of PSP occur in different conditions. 相似文献
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Erina Fujiwara-Nagata Yoko Eguchi Ryutaro Utsumi Mitsuru Eguchi 《Fisheries Science》2007,73(2):348-355
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Larvae of the Siamese fighting fish Betta splendens were reared on the mass-cultured small freshwater rotifer Brachionus angularis Laos strain (UTAC-Lao), Paramecia sp., and Artemia as live food sources. Larvae fed live food were found to have a significantly high survival rate (97.5–100%) 18 days after
hatch (DAH) in comparison to the control unfed larvae, which died by 12 DAH. Rotifer-fed larvae were found to grow faster
than paramecia-fed larvae. The fastest growth rate was observed in larvae fed a combination of rotifer and Artemia, with growth in these larvae increasing by 282% by 18 DAH [total length (TL) 11.3 ± 1.2 mm] relative to body measurements
taken 3 DAH. The next fastest growth rate was observed in rotifer-fed larvae, with a 158% increase in growth observed by 18
DAH (TL 7.6 ± 0.5 mm). The paramecia-fed larvae were found to grow by only 54.3% (TL 4.6 ± 0.1 mm) during the same period. 相似文献
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ABSTRACT: Lactic acid fermentation of seaweed is a recent topic and quite limited information is available on culture conditions. To know the suitable strains for use as a starter culture for seaweed fermentation, 14 lactic acid bacteria (LAB) strains, including 11 species, were tested in culture conditions prepared with or without salt. A commercial product of Undaria pinnatifida powder was used as a substrate for fermentation without sterilizing. Starter-suitability of the LAB strains was assessed from their predominance after culture. Among the tested strains, Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus casei and Lactobacillus rhamnosus showed high (>90%) predominance in their cultures, while control cultures prepared without inoculation of LAB did not show any detectable growth of acid producing bacteria and spoiled. A total of 102 strains not showing acid producing activity were isolated and characterized from spoiled cultures, and all the isolates were observed as Bacillus strains, including 64 strains (62.7%) and 16 strains (15.7%) of a Bacillus cereu s-related and B. fusiformis -related species, respectively. The Undaria substrate before fermentation contained culturable microorganisms at 1.4–3.1 × 102 CFU/g, but the Bacillus cereu s-related strain was not a major composition, suggesting a concern of selective growth of the Bacillus cereu s-related strain during the spoiled fermentation. 相似文献
18.
热带印度洋大眼金枪鱼渔场时空分布与温跃层关系 总被引:1,自引:0,他引:1
为了解印度洋大眼金枪鱼(Thunnus obesus)温跃层参数适宜分布区间及季节变化,采用Argo浮标剖面温度数据重构热带印度洋各月平均温跃层特征参数,并结合印度洋金枪鱼委员会(IOTC)大眼金枪鱼延绳钓渔业数据,本文绘制了月平均温跃层特征参数和月平均CPUE的空间叠加图,用于分析热带印度洋大眼金枪鱼渔场CPUE时空分布和温跃层特征参数的关系。结果表明,热带印度洋温跃层上界深度、温度和下界深度都具有明显的季节性变化,大眼金枪鱼中心渔场分布和温跃层季节性变化有关。夏季季风期间,高CPUE渔区温跃层上界深度在30~50 m,浅于冬季的50~70 m;温跃层上界温度范围为24~30℃。在冬季季风期间,高CPUE区域对应的温跃层上界温度范围为27~30℃;从马达加斯加岛北部沿非洲大陆至索马里附近海域,温跃层下界深度在170~200 m时的渔区CPUE普遍较高;当深度超过300 m时,CPUE值均非常低。采用频次分析和经验累积分布函数计算其最适温跃层特征参数分布,得出大眼金枪鱼最适温跃层的上界、下界温度范围分别是26~29℃和13~15℃;其上界、下界深度范围分别是30~60 m和140~170 m。文章初步得出印度洋大眼金枪鱼中心渔场温跃层各特征参数的适宜分布区间及季节变化特征,为金枪鱼实际生产作业和资源管理提供理论参考。 相似文献
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Dimitrios Karagiannis Ioannis N. Vatsos Panagiotis Angelidis 《Aquaculture International》2011,19(1):103-110
Shellfish farming often takes place in areas subjected to various recurring pollutions. The intensive use of herbicides in
agriculture leads to the presence of residues in the aquatic ecosystems. In the present study, the effects of atrazine on
the viability of the mussel Mytilus galloprovincialis and the formation of their byssus were studied. A total of 720 mussels (mean length 24 mm ± 2.1 SD) were divided into six
groups. The mussels from the first five groups were exposed to five concentrations of atrazine, 10, 8, 5, 2 and 1 ppm, while
one group was used as control. The LC50 was calculated after 48 h, while the long-term effect of atrazine on the viability and byssus formation of the mussels were
studied for 21 days. The LC50 was found to be 6.33 ppm. From all the concentrations of atrazine to which the mussels were exposed, only in two of them
(2 and 1 ppm) some mussels survived up to the last day of the experiment. The survival rate in the control group was significantly
higher than those of mussels that were exposed to atrazine. Regarding the byssus formation, the number of byssal threads was
significant lower in the mussels that were exposed to 2 and 1 ppm atrazine compared to the control group, while no byssal
threads were formed by the mussels exposed to 10, 8 and 5 ppm. All the mussels that survived on day 21 were then exposed to
air. The LT50 for the control group and the mussels which had been exposed to 1 and 2 ppm atrazine were 5.14, 2.77 and 1.98 days, respectively.
The results of the present study indicate that atrazine has a significant effect on the viability of mussels both in the water
and in air and on their ability to form byssus. 相似文献
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Seok Jin Oh Dae -Il Kim Takao Sajima Yohei Shimasaki Yukihiko Matsuyama Yuji Oshima Tsuneo Honjo Han -Soeb Yang 《Fisheries Science》2008,74(1):137-145
ABSTRACT: We investigated the effects of specific light wavelengths from light-emitting diodes (LEDs) on the growth of the dinoflagellate Heterocapsa circularisquama , which kills bivalves, and the diatom Skeletonema costatum , which is an important food source for bivalves. Growth of H. circularisquama was obviously inhibited at 590 nm and a photon flux density less than 75 μmol quanta/m2 /s. However, growth of S. costatum was not suppressed by irradiance from any LEDs tested from near-ultraviolet to near-infrared wavelengths at 75 μmol quanta/m2 /s. The growth rate of H. circularisquama in an experimental treatment group with irradiance provided by both cool-white fluorescent lamps (12:12 h L : D cycle) and a 590-nm LED (continuous irradiance) was 0.43/day. In the control group with irradiance provided only by cool-white fluorescent lamps (12:12 h L : D cycle), the growth rate was 0.63/day, indicating that growth of H. circularisquama was suppressed by 590 nm (less than 75 μmol quanta/m2 /s) irradiance from the LED and the continuous irradiance. The use of 590-nm LEDs in bivalve culture at irradiance levels less than 75 μmol quanta/m2 /s might encourage the growth of the useful diatom S. costatum without stimulating growth of the harmful dinoflagellate H. circularisquama . 相似文献