首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 305 毫秒
1.
紫红笛鲷人工繁殖及育苗技术研究报告   总被引:2,自引:1,他引:2  
利用海水土池或网箱养殖三龄以上的紫红笛鲷成鱼,于催产前三个月进行强化培育。在水温达到 20.0℃以上的春、夏季,用绒毛膜促性腺激素(HCG)和释放激素(LRH-A_(2-3))进行催产,混合或单一使用,剂量视亲鱼性腺成熟度而定。受精卵在盐度27.9-33.5,水温26.5-30.5℃,pH8.2的水环境中经15-17h孵化。开口仔鱼在土池水温27.2-35.5℃.盐度:23.5-35.6.pH8.0-9.5的条件下,经28-30d培育.鱼体全长为2.5-3.2cm,仔鱼变态完全,成为幼鱼。  相似文献   

2.
笔者于2005年在徐闻县大井育苗场进行了珠母贝人工育苗试验.在水温27.3℃,盐度30.8,pH 8.1的条件下,选取雄贝3只,雌贝12只进行人工授精,受精率为89.6%,受精6.25h胚胎发育至担轮幼虫,19h发育至直线绞合幼虫.在水温27.1℃~30.2℃,盐度30.4~31.3,pH 8.1的条件下,幼虫经56d的培育,共培育出4cm±0.3cm的珠母贝苗163.8只,取得了珠母贝人工育苗试验的成功.  相似文献   

3.
褐毛鲿仔鱼室内培育与稚幼鱼土池生态育苗技术研究   总被引:1,自引:0,他引:1  
褐毛鲿(Megalonibea fusca)育苗采用仔鱼室内高密度培育和稚幼鱼土池生态培育相结合的育苗方式.孵化后的仔鱼在室内培育到稚鱼期,移入土池前先用鱼浆肥水培养饵料生物,鱼苗下池后一直用鱼浆或鱼糜投喂,直到出塘.土池4口总面积2.27 hm2,同时投放全长范围9.9~12.6 mm的稚鱼共53.0×104尾.秋季土池培育期间水温范围18.4 ~23.0℃,盐度13~ 25,pH 8.3~8.8.经过50 d的培育,共培育出全长范围35 ~ 69 mm,平均全长48 mm的苗种28.68×104尾,土池阶段育苗成活率为54.1%.用鱼浆肥水的水色为清绿色,水质稳定,饵料生物种群数量丰富,投放较大规格仔稚鱼可以提高育苗成活率.  相似文献   

4.
2003年4~5月利用低盐度(12)河口水在上海崇明进行了轮虫土池培育实验,并对其脂肪酸营养进行了分析和评价。经过33d培养,结果表明,(1)只要管理得当,低盐度、自然水温(平均水温为18.2℃)条件,土池培育轮虫可以实现持续稳定供应,采收时间、每日采收量和亩总产量分别达到28~29d、9.2kg/667m2·d和259kg/667m2,最高密度可达45个/ml;(2)敌害生物和饵料条件是土池培育轮虫持续稳产的关键因素;(3)土池培育轮虫EPA、DHA、AA等HUFA含量高于酵母和微绿球藻培育的轮虫,因此土池培育轮虫的营养价值好,适用于海水苗种培育。  相似文献   

5.
卵形鲳鲹人工养殖试验   总被引:1,自引:0,他引:1  
卵形鲳鯵是新开发的的海水养殖经济鱼类,本试验利用海水网箱及土池进行养殖,投喂配合饲料,叉长4~5 cm的种苗,在水温18℃~32℃、盐度15~31、pH值7.8~8.1的养殖条件下,经4~5个月养殖,体重可达400~600g,当年达到商品规格。  相似文献   

6.
黄鳍东方鲀人工育苗技术初步研究   总被引:4,自引:0,他引:4  
本文报道了福建省水产研究所2005年黄鳍东方鲀人工育苗技术研究结果.在水温18.6~20.2℃、盐度27.3~28.6条件下,亲鱼催产效应时间为39~49h;在水温18~21℃、盐度27.3~28.6条件下,受精卵孵化时间为120~216h;在水温18~21℃、盐度20.0~30.0条件下,室内水泥池前期培育13d,仔鱼成活率69.7%;在水温26.0~29.0℃、盐度15.0~30.0条件下,30万尾稚鱼经池塘50d后期培育,共培育出平均全长3.9cm、平均体重1.1g幼鱼5.0万尾,成活率16.7%.  相似文献   

7.
通过模拟工厂化养殖模式,采用单因素实验方法进行水质环境因子(溶解氧、水温、光照、盐度及pH值)梯度饲养试验,经过30d或60d饲养,对条石鲷的增长率及饵料系数进行比较分析。结果表明:适宜工厂化养殖条石鲷的水质环境为溶解氧≥6mg/L、水温24~26℃、光照300~900Lux、盐度25—30‰、pH值7.5-8.5。  相似文献   

8.
莫桑比克鳗鲡养殖生物学主要特性研究   总被引:5,自引:1,他引:4  
对莫桑比克鳗鲡(Anguillamor morata)玻璃鳗经形态学鉴定品种后,开展了主要养殖生物学特性研究。耐受高温和低温分别为39℃和7℃,适宜生存水温15℃~33℃;耐受盐度与水温相关,水温30℃致死盐度2.9%,适宜盐度小于1.1%,20℃致死盐度2.7%,适宜盐度小于1.8%,10℃致死盐度2.1%,适宜盐度小于2.0%;耐受pH值与水温相关,30℃致死pH值分别为3.5和11.0,适宜pH值6.0—7.0,20℃致死pH值分别为4.0和11.0,适宜pH值6.0~8.0,10℃致死pH值分别为3.5和10.5,适宜pH值5.5—8.5。常用药物S高聚碘、二氧化氯、三氯异氰尿酸、苯扎溴铵、溴氯海因、甲醛、敌百虫的安全浓度高于或接近常用浓度,硫酸铜、溴氰菊脂乳油、氯氰菊脂、甲苯咪唑的安全浓度低于常用浓度。水体中非离子态氨的安全浓度为2.51mg/L,亚硝酸氮的安全浓度为55.12mg/L。  相似文献   

9.
点篮子鱼人工繁育技术研究   总被引:9,自引:6,他引:3  
2008年4~6月在海南进行了点篮子鱼的人工繁殖试验,共产卵610×104cell,孵化出仔鱼342.4×104ind,经过30 d土池生态培育,培育出体长约2.5 cm幼鱼32.5×104ind,土塘培育苗种成活率达16.1%。点篮子鱼适宜催产的环境条件为:水温25.5~27.7℃,盐度33.0~34.5,pH值7.9~8.5,DO值6.0~8.8 mg/L。A、B、C三种药品配伍进行催产效果最好,获产率、受精率、孵化率均最高,分别达到60.0%~80.0%、83.2%~90.5%和71.2%~76.8%,效应时间缩短到15~16 h。点篮子鱼受精卵为半浮性卵,孵化积温为649.25时度。当盐度低于26.5时,点篮子鱼受精卵沉于水底;盐度高于38.5时,则浮于水面。水温对胚胎发育影响较大,15℃、20℃试验组胚胎分别发育至原肠晚期、胚孔封闭期死亡,35℃条件下胚胎发育终止于胚体形成期,30℃试验组初孵仔鱼的活力差,畸形率高。点篮子鱼胚胎发育的适温为25℃左右。盐度对点篮子鱼的胚胎发育的影响较大。在盐度34.4~45.7范围内,随着盐度的增加,孵化率降低,畸形率升高。在盐度30.2~34.4范围内,孵化率在60%以上,畸形率在10%以下,最适盐度范围30.2~34.4。初孵仔鱼全长为1.00~1.20 mm,油球一个,出膜3~4 d开始摄食小型轮虫和藻类。点篮子鱼苗15日龄前生长缓慢,之后生长迅速,平均全长与日龄回归方程式为:y=1.120 7e0.109 4x,R2=0.979 5。  相似文献   

10.
赤眼鳟人工繁殖与苗种培育技术   总被引:5,自引:0,他引:5  
试验进行了野生赤眼鳟(Squaliobarbus curriculus)的人工驯养、繁殖及苗种培育,并对其受精卵的胚胎发育情况进行了观察,结果表明:单独使用或组合使用促黄体素释放激素类似物(LRH-A2)、马来酸地欧酮(DOM),以胸腹注射法进行一针或两针人工催产,效果都较好,效应时间一般随水温升高而缩短,24℃~27.5℃一针注射后的效应时间为10~12 h;22℃~23℃两针注射(距第二针)的效应时间为8h左右;浮盘与水泥池组合式孵化方式合理、可靠,3年累计孵出鱼苗218.2万尾;赤眼鳟的孵化时间与水温呈负相关,水温越高,孵化时间越短,在21~24℃时,一般需32 h孵出,而当水温上升至24~27.5℃时,则仅需20~24h即可出膜;鱼种培育阶段,生长较快,冬片鱼种规格也能达到10 cm~15 cm,3年累计育出赤眼鳟冬片鱼种22.81万尾,平均成活率达82.95%.  相似文献   

11.
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   

12.
13.
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   

14.
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   

15.
16.
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.  相似文献   

17.
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   

18.
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   

19.
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   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号