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1.
淤泥湖近太湖新银鱼的生长研究   总被引:2,自引:0,他引:2  
对生活在湖北淤泥湖中的近太湖新银鱼进行了生长研究。结果为:①全长与体重的相关关系:W=2.312×10^-6L^3.00;②全长生长方程:Lt=72.3(1-e^-0.3(t^-0.1)),体重生长方程Wt=0.8738(1-e^-0.3(t^-0.1))^3。③L∞=72.3(mm),W∞=0.8738(g),k=0.3t=0.1,拐点年龄ti=3.7月龄,拐点体重Wi=0.25g。  相似文献   

2.
通过对池塘养殖大银鱼子代的一年生长实测和统计,得到结果如下:(1)子代大银鱼在 养殖也能迅速生长,经10个月饲养,平均长达117.92mm,平均体重8.50g;(2)体长与体重的关系为W=1.304×10^-6L^3.293;(3)大银鱼生长与池中适口饵料数量有关。  相似文献   

3.
史氏鲟南移驯养及生物学的研究 I.1龄鱼的生长特性   总被引:14,自引:2,他引:12  
首次将史氏鲟从黑龙江南移至长江流域人工条件下驯养,培育成1龄幼鱼,11月龄的个体最大值重为1053克,均重606克,最大体长898毫米,均长569毫米,幼鱼的最适生长水温为19.8℃,在17-21℃水温条件下,生长迅速,1龄鱼全长与体重的关系式为W=0.001302L^3.2268(r=0.9996)体重生长曲线公式为W=6.777892e^0.3855t(r=0.9935)。  相似文献   

4.
长江口花鲈的生长和食性   总被引:12,自引:2,他引:10  
花鲈为沿海及河口的经济鱼类,亦可溯河生活于淡水。在长江口水域,花鲈属中型鱼类,其体长和体重的相关关系式为:W=0.0605L^2.6346(r=0.9878),生长方程为:Lt=100.9957[1-e^0.1768(t+0.7633)],Wt=11542.26[1-e^-1768(t+0.7633)]^2.6346,体重生长拐点tr=4.7龄,拐点处体重为3281.4克。早期幼鱼以浮游动物为食,  相似文献   

5.
暗纹东方Tun苗种期生长规律的研究   总被引:1,自引:0,他引:1  
在湖泊网箱培养条件下,河Tun鱼苗种生长特点是,全年体长呈均衡增长,其中8月中下旬-10月中旬发为体长主要增长期,体重前期增长不平稳,中期体重剧增为主要增长期,后期又趋向平稳;体长与体重生长指数方程为W=0.0158L^3.3857,鱼龄1→1龄年增积量为0.8276cm.kg。  相似文献   

6.
网湖鲤鱼生长的研究   总被引:1,自引:0,他引:1  
研究了网湖鲤鱼的生长特性。体长与鳞径的关系为L-4.7402S-4.0194。体长与体重的关系为W=0.0112L^3.180.用VonBertalanffy生长方程表达网湖鲤鱼体长、体重与年龄的关系:Lt-75.16[1-1^-0.1729(t+08029)],Wt=11077.31[1-1^0.1729(t+0.8029]^3.1980。拐点年龄为ti=t.55齿,拐点体长Li=50.10cm  相似文献   

7.
首次将史氏鲟从黑龙江南移至长江流域人工条件下驯养,培育成1龄幼鱼,11月龄的个体最大体重为1053克,均重606克;最大体长为898毫米,均长569毫米。幼鱼的最适生长水温为19.8℃在17—21℃水温条件下,生长迅速。1龄鱼全长与体重的关系式为W=0.001302L3.2268(r=0.9996),体重生长曲线公式为W=6.777892e0.3855t(r=0.9935)。  相似文献   

8.
珠江斑Hu年龄和生长的研究   总被引:6,自引:0,他引:6  
观察珠江斑Hu的胸鳍和鳃盖骨,研究其年龄特征、渔获物年龄组成和体长、体重组成,并对其体长与鳃盖骨长、体长与体重的关系,以及生长规律进行了分析。其年轮形成时间为12月~翌年3月;体长与鳃盖骨长的关系式为L=34.76R+0.4533,体长与体重的关系式为W=0.032L^3.1872。生长Von Bertalanffy方程分别为Lt=156.75「1-e^-0.089(t-0.0168)」和Wt=3  相似文献   

9.
黄鳝的营养素需要量及饲料最适能量蛋白比   总被引:32,自引:1,他引:31  
杨代勤 《水产学报》2000,24(3):259-262
用正交设计法L9(3^4)配制九种试验饲料,对黄鳝配合饲料中蛋白质、脂肪、总能、无机盐需要量及最适能量蛋白比进行了研究,结果表明,影响黄鳝生长的主要因素是蛋白质和总能,黄鳝最佳生长所需饲料中蛋白质含量为35.7%,总能为11.50 ̄12.50kJ.g^-1饲料,脂肪含量3% ̄4%,无机盐含量3%,总糖24% ̄33%。黄鳝饲料的最适能量蛋白比(E/P=kJ.g^-1)为31.6 ̄38.9。  相似文献   

10.
池养大鲵生长发育的初步研究   总被引:9,自引:1,他引:8  
1995~1998年在卢氏县大鲵繁育场对池养大鲵的生长发育进行了初步研究。结果表明,Ⅰ~Ⅵ龄大鲵体长的增长较为均衡,年平均增长12524cm,Ⅶ龄后变慢。体重的增长明显快于野外种群,符合Logistic生长曲线方程^Y=3583561+182572e-1.5272x(r=0992),V龄前后是大鲵生长的关键时期。体长和体重之间的关系符合幂函数曲线方程^Y=000684X3.0257(r=09997)。池养大鲵休眠期变短,性成熟年龄与野外种群相似。  相似文献   

11.
12.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

13.
Growth hormone (GH) and reproduction: a review   总被引:5,自引:0,他引:5  
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.  相似文献   

14.
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.  相似文献   

15.
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.  相似文献   

16.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

17.
18.
The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.  相似文献   

19.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.  相似文献   

20.
  1. Humanity is facing a biodiversity crisis, with freshwater-associated biodiversity in a particularly dire state. Novel ecosystems created through human use of mineral resources, such as gravel pit lakes, can provide substitute habitats for the conservation of freshwater and riparian biodiversity. Many of these artificial ecosystems are subject to a high intensity of recreational use, however, which may limit their biodiversity potential.
  2. The species richness of several taxa (plants, amphibians, dragonflies, damselflies, waterfowl, and songbirds) was assessed and a range of taxonomic biodiversity metrics were compared between gravel pit lakes managed for recreational fisheries (n = 16) and unmanaged reference lakes (n = 10), controlling for non-fishing-related environmental variation.
  3. The average species richness of all the taxa examined was similar among lakes in both lake types and no substantial differences in species composition were found when examining the pooled species inventory. Similarly, there were no differences between lake types in the presence of rare species and in the Simpson diversity index across all of the taxa assessed.
  4. Variation in species richness among lakes was correlated with woody habitat, lake morphology (surface area and steepness), and land use, but was not correlated with the presence of recreational fisheries. Thus, non-fishing-related environmental variables had stronger effects on local species presence than recreational fisheries management or the presence of recreational anglers.
  5. Collectively, no evidence was found that anglers and recreational fisheries management constrain the development of aquatic and riparian biodiversity in gravel pit lakes in the study region; however, the conservation of species diversity in gravel pit lakes could benefit from an increasing reliance on habitat enhancement activities.
  相似文献   

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