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751.
自澳大利亚引进淡水黑鲷10000尾。进行试养。报道了淡水黑鲷的各方面生物学特性。以及其人工繁殖、苗种培育、越冬保种、成鱼养殖、疾病防治等成套技术。  相似文献   
752.
Spawning and successful rearing of larvae of honeycomb grouper Epinephelus merra Bloch 1793 upto juvenile stage was accomplished at the finfish hatchery of Mandapam Regional Centre of Central Marine Fisheries Research Institute during 2004. The fertilized eggs were free, spherical and buoyant with size ranging from 710 to 730 μm. Complete early embryonic development took place within 24–27 h and hatching occurred. The hatchlings measured 1.5 mm. Mouth opening (115 μm) appeared at 72 h when the larvae were 2.2 mm in size. Pectoral fin developed on the fifth day. Complete metamorphosis took place and by the 60th day the larvae transformed into juveniles (45 mm) and attained skin colouration and honeycomb pattern.  相似文献   
753.
Ontogenic development of some digestive enzymes (proteases, amylase and lipase) in common pandora Pagellus erythrinus larva was assayed during larval development. The green‐water technique was employed for larval rearing, and whole‐body homogenates were used for enzymatic assays in triplicate. Important alterations in specific activities of all digestive enzymes measured during the period of this study were mostly related to metamorphosis and weaning. Mouth opening was observed on day 3 at 2.23±0.01 mm total length synchronously with the first determination of trypsin and chymotrypsin activities. After this date, the specific activities of these slightly increased until 25 days after hatching (DAH), respectively, and then slightly decreased and changed. The pattern determined for pepsin was strongly related to stomach formation on day 25 at 9.72±2.3 mm total length and a sharp increase was found until 30 DAH and then a slight decrease was measured from this date until the end of the experiment. Both amylase and lipase were measured for the first time on days 2 and 4, respectively, and also the specific activities of these showed similar patterns during the first week of the study. Then, slight variations were observed until 30 DAH and while lipase‐specific activity had declined, an increase in the specific activity of amylase was found until the end of the experiment. Finally, it is thought that the variations observed in the specific activity in the profile of digestive enzymes were related to either metamorphosis such as formation of stomach (25 DAH) or to changes in characteristics of food (30 DAH). The pattern of development of the main digestive enzymes found in P. erythrinus is similar to that described in other Sparid species.  相似文献   
754.
Cu2+、Hg2+、Cd2+、Pb2+对淡水石斑鱼仔鱼的急性毒性研究   总被引:3,自引:0,他引:3  
试验探讨了Cu2 、Hg2 、Cd2 、Pb2 4种重金属离子对淡水石斑鱼仔鱼的急性毒性作用。试验表明:Hg2 、Cd2 、Cu2 和 Pb2 对淡水石斑鱼仔鱼的96hLC50分别为0.069 mg/L、0.48 mg/L、0.928 mg/L和3.421 mg/L,安全浓度分别为0.00069 mg/L、 0.00481 mg/L、0.00978 mg/L和0.0321 mg/L。急性毒性由强至弱依次为:Hg2 >Cd2 >Cu2 >pb2 。  相似文献   
755.
三乙醇胺诱导中间球海胆变态的研究   总被引:2,自引:1,他引:2  
就三乙醇胺对于中间球海胆幼体变态的诱导作用进行了研究。实验结果表明,三乙醇胺对中间球海胆有良好的变态诱导作用,1×10-4mol/L的三乙醇胺作用10h诱导效果最佳,在提高变态率的同时,极显著地降低了死亡率。  相似文献   
756.
瓣结鱼的胚胎及幼鱼发育   总被引:21,自引:1,他引:21  
谢恩义 《水产学报》2002,26(2):115-121
首次记述了瓣结鱼的早期发育过程,对其胚胎及幼鱼发育各期特征先后进行了3次较为仔细的观察,并记述了胚胎发育的积温、积累度时值以及从孵化到105d的幼鱼的生长数据。成熟卵直径1.7~1.9mm,受精卵吸水膨胀后,外膜径达2.5~2.7mm,具粘性。在水温20.5~23.0℃条件下,受精卵历时71h7min孵化,初孵仔鱼平均全长6.6mm,经65~72d,幼鱼发育基本完成,对瓣结鱼胚胎发育的下限温度及早期发育作了探讨。  相似文献   
757.
为研究GABA及其受体拮抗剂荷包牡丹碱(GABAA受体)和CGP52432 (GABAB受体)在厚壳贻贝幼虫附着变态中的调控作用,实验通过分析厚壳贻贝不同发育阶段幼虫转录组数据获得GABA受体相关蛋白基因(GABARAP)和GABAB2受体基因(GABAB2R),发现GABAB2R在变态前期的眼点幼虫阶段相较于其他阶段幼体显著高表达。通过实时荧光定量PCR验证也得到相似的表达模式,显示GABAB2R可能参与调控厚壳贻贝幼虫变态发育。药理学实验结果显示,10-4 mol/L GABA对厚壳贻贝幼虫的变态具有诱导活性(27.2%±3.0%)。在拮抗剂实验中,10-6~10-4 mol/L荷包牡丹碱和CGP52432均显著抑制了厚壳贻贝幼虫变态,且抑制作用随浓度升高而增强。实验还发现GABA及其受体拮抗剂都抑制了厚壳贻贝幼虫的游泳行为。研究表明,GABAA或GABA...  相似文献   
758.
The identification of factors contributing to strong year classes of marine fishes has been a constant goal toward a mechanistic understanding of recruitment variability. Here, we explored a 26-year time series of the abundance of early juvenile red drum along the North Carolina coast to identify environmental features associated with variable recruitment success. The study location was near the northern edge of the species latitudinal range, and we hypothesized that consistent environmental forcing would be linked to the formation of strong red drum year classes. Patterns of variability in seasonal environmental features were disaggregated into multiple forms of temporal periodicity and analyzed using generalized additive models. We also contrasted patterns of environmental variation that occurred during the strongest recruitment events with those coinciding with the weakest red drum year classes. The early shift, during August, to favorable wind conditions was the most consistent environmental feature associated with red drum recruitment success. The combined duration and magnitude of N and NE winds during August of strong recruitment years was nearly double the level observed during weak recruitment years. Elevated nearshore sea surface temperatures early in the spawning season were also found to occur during years that produced strong year classes. Coastal productivity, indexed using chlorophyll a concentration, was positively associated with red drum recruitment, but also highlighted the need for more spatially resolved productivity data. Our findings highlight the importance of environment-recruitment linkages for marine fishes, especially near distributional boundaries where conditions to promote year class success can be brief.  相似文献   
759.
Coastal winds transport water masses and larval fish onshore or offshore which may influence estuarine recruitment, yet our understanding of the mechanism underlying this relationship is limited. Here, we combine datasets from a historical database of larval fish off southeast Australia with a high-resolution atmospheric reanalysis model to show that normalised abundance of coastally spawned larvae increased with weak to moderate upwelling favourable winds 14 days prior to sampling. The increase in abundance may reflect increased nutrient and plankton availability for larval fish. Normalised larval abundance decreased following strong upwelling favourable winds but increased after onshore (downwelling favourable) winds, due to wind-driven transport. By combining a commercial estuarine fisheries catch-rate dataset (4 species, 8 estuaries, 10 years) and the high-resolution atmospheric reanalysis model, we show that negative effects of upwelling favourable winds during the spawning period can be detected in lagged estuarine commercial fisheries catch rates (lagged by 2–8 years depending on species' growth rates), potentially representing the same mechanism proposed for larval fish. Upwelling favourable winds in the southeast Australian region have increased since 1850 while onshore winds have decreased, which may have reduced larval recruitment to estuaries. Coastal winds are likely an important factor for estuarine recruitment in the southeast Australian region and future research on the estuarine recruitment of fish should incorporate coastal winds.  相似文献   
760.
系统比较了亲本强化培育和常规培育对池塘养殖中华绒螯蟹的生殖性能和Z_1幼体质量的影响,同时分析2组Z_1幼体的脂肪酸组成。结果表明,①两种培育方式对亲本的成活率和产卵率均无显著影响,强化组亲本的GSI、HSI、产卵量和生殖力显著高于常规组;②两种培育方式对卵的卵径、水分含量、单卵干重和湿重影响不显著,但强化组的受精率和孵化率略高于常规组;③强化组Z_1幼体的头胸甲长度、变态速度和抗逆境能力均高于常规组,这可能和幼体中高含量的HUFA有关;④生产性实验结果表明强化组的出苗率高于常规组,且幼体培育时间减少4~5 d。因此,亲本强化培育可以显著提高绒螯蟹中华的生殖性能和Z_1幼体质量。  相似文献   
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