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1.
暗纹东方鲀生殖洄游期性腺发育特点及人工繁殖的研究   总被引:3,自引:1,他引:2  
1996~1998年,作者从长江下游扬中段采捕暗纹东方鱼屯亲鱼,经暂养促熟处理(微流水刺激、投喂鲜活饵料、不定期注射适量的LHRH-A2),雌鱼的性腺可发育到Ⅳ期末,对外源激素能引起正常的排卵反应。同时观察了Ⅲ、Ⅳ、Ⅴ期性腺发育的特点。催产药物为LHRH-A2和PG,三针注射,雌鱼剂量为35mgPG+60μgLHRH-A2/kg,雄鱼剂量减半。在水温18~22℃的条件下,效应时间为10~36小时;在21~22℃时,胚胎发育时间为139~210小时。1997~1998年的平均受精率为834%,平均孵化率为780%。  相似文献   

2.
暗纹东方Tun生殖洄游期性腺发育特点及人工繁殖的研究   总被引:2,自引:0,他引:2  
1996 ̄1998年,作者从长江下游扬中段采捕暗纹东方Tun亲鱼,经暂养促熟处理(微流水刺激、投喂鲜活饵料、不定期注射适量的LHRH-A2),雌鱼的性腺可发育到IV期末,对外源激素能引起正常的排卵反应。同时观察了Ⅲ、Ⅳ、Ⅴ期性腺发育的特点。催产药物为LHRH-A2和PG,三针注射,雌鱼剂量为3.5mgPG+60μgLHRH-A2/kg,雄鱼剂量减半。在水温18 ̄22℃的条件下,效应时间为10 ̄36  相似文献   

3.
1注重亲鱼的选择选择的雌鱼要求腹部膨大、松软 ,卵巢轮廓明显 ,外生殖乳突出而圆 ;雄鱼外生殖乳突长而尖 ,胸鳍刺上有强大锯齿。2适时催产选择性成熟的亲鱼在3~4月产卵盛期 ,天气比较稳定、水温适宜(20~23℃)的时间进行催产。3催产是关键笔者对4龄大口鲶共25尾催产全部获得成功。雌鱼17尾 ,总重50.2kg;雄鱼8尾 ,总重16.5kg。催产水温为23~23.5℃ ,选用宁波激素制品厂生产的HCG和LRH A作催产剂。3.1注射剂量雌鱼第1针剂量为HCG1000IU/kgHCG LRH A1.5μg/kg 。…  相似文献   

4.
黄颡鱼人工繁殖及苗种培育技术的初步研究   总被引:3,自引:0,他引:3  
2000年5~6月共计催产黄颡鱼3批,计重57kg,♀209尾,♂222尾,采用PG、LRH-A2、HCG、DOM中的2种或3种混和进行2次注射,水湿25~28℃,效应时间为15~20h,共计产黄颡鱼卵20.8万粒,经48~70h孵化出苗48 000尾,平均催产率、受精率、孵化离分别为30.4%、51.5%、44.5%,经过15~20d的培育,投喂水蚤和碎鱼肉浆培育成2~3cm的黄颡鱼鱼苗20 0  相似文献   

5.
1 鱼苗孵化及苗种培育1.1 人工催产 水温控制在21℃-23℃左右,催产季节在4月下旬至6月。每尾雌鳅注射HCG 100~150国际单位或LRH-A5~10ug,雄鳅剂量减半。注射后按雌雄比例 1:2或者1:3放入水缸或水池中,8~10hr后产卵。人工投精的操作方法是:用手轻挤雌雄亲鳅腹部,把卵粒和精液在短时间内同时挤入事先清洗干净的瓷盆内,使卵粒和精液充分混合受精,撒在鱼巢上,放入孵化器进行孵化。受精卵在水温20℃-30℃范围内都能正常孵化。孵化的适宜水温为20℃~28℃,每天需换水2次,约30…  相似文献   

6.
长江大鳍鱯的人工繁殖   总被引:1,自引:0,他引:1       下载免费PDF全文
本文对长江大鳍亲鱼的池塘培育和人工繁殖技术进行了研究。1992年~1994年期间,采用池塘混养技术,将长江野生大鳍引入池塘进行驯化和培育,连续2年获得成熟亲鱼并进行人工繁殖。在池塘环境中,大鳍雌亲鱼成熟率分别为818%和706%,雄亲鱼分别为100%和935%。采用多种催产药物混合注射的催产方法,可以得到较好的催产率。大鳍人工繁殖适宜的催产剂量是雌鱼每g体重注射LRH-A03~05μg、DOM003~005mg和HCG5~10IU,雄鱼减半或同量。水温24~26℃时,催产效应时间为12~13h。受精卵在水温27~29℃时需53~55h孵化出膜。大鳍人工繁殖受精率不高与其雄鱼精巢特殊的组织结构有关。  相似文献   

7.
一、亲鱼培育1.亲鱼的越冬培育冬季当水温在20℃以上时,亲鱼能正常摄食,必须投放饲料,日投饲量为鱼体重的2%~3%。饲料以蛋白质30%左右的人工颗粒饲料为主,每隔2~3天还喂谷芽和青菜各1次(约占鱼体重的1%左右)。当水温降至18~20℃时投喂量可减少到鱼体重的1%左右。水温在17℃以下时可不喂饲料。越冬期间亲鱼池如水质污浊可在天晴、阳光充足的天气里换一半水或三分之一原池水,若无晴天而水质又污浊,可每亩平均水深1.0米用0.5千克明矾溶水全池泼洒,也可起到一定的净水作用。2.亲鱼产前的强化培育当…  相似文献   

8.
我们利用温室进行亲鱼提早培育、繁殖、工厂化育苗,1998年6月份向室外池塘投放当年鱼种,9月份养成4009以上规格的商品鱼。具体试验情况如下。一、材料与方法1.鱼池与水源(1)培育鱼种地:室内水泥地,面积100m2,池深1.5m,水深1.3m,水源为地下水,用蒸汽加热。(2)商品鱼池塘:室外土地,面积14000m2,池深3m,水源为大庆水库。2.淡水白鲳亲鱼提早培育亲鱼33尾,其中雄鱼14尾,雌鱼19尾,体重4-5kg。从1月5日起将亲鱼池水温逐渐提高至(28±0.5)℃,投喂含粗蛋白35%的饲料,投喂量为鱼体重的6%-8%,另每天投喂2%的青菜。流…  相似文献   

9.
江河中收集南方鲶亲鱼,在14.5℃~15.0℃水温条件下进行人工授精和药物催产。雌鱼自行流出的卵经人工授精发育良好,孵化率高;雌鱼注射催产药物后人工挤压能获得部分卵粒,但受精率、孵化率低。  相似文献   

10.
细鳞斜颌鲴人工繁殖技术初探   总被引:1,自引:0,他引:1  
用DOM3—5mg+LRH—A50—100μg/kg人工催产细鳞斜颌鲴2批,共134尾,其中雌(♀)90尾、雄44尾.催产率100%,受精率70%以上,出苗率40%-80%。获卵粒数916万粒,鱼苗409万尾.  相似文献   

11.
12.
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   

13.
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   

14.
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   

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.
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   

18.
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.
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).  相似文献   

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