冷冻等处理对不同孵化进程的卤虫卵存活率的影响

本文研究了冷冻、双氧水和干燥处理对处于不同孵化进程中的卤虫卵的存活率（孵化率）的影响。冷冻对未经孵化处理的卵的孵化率影响很小，冷冻1-8周，基本保持不变。孵化进行了3个小时的卤虫卵，冷冻8周后，其孵化率降低了10个百分点。孵化进行了6个小时的卤虫卵，冷冻8周后，其孵化率降低了31个百分点。孵化进行79个小时的卤虫卵，冷冻8周后，其孵化率降低740个百分点。处于不同孵化阶段的卤虫卵经冷冻处理8周后，再经3％双氧水处理10分钟和40℃干燥处理6小时，其孵化率表现为不同的特点。未经孵化处理卵的孵化率基本保持不变。孵化进行了3个小时的卤虫卵，其孵化率再次降低5个百分点。孵化进行了6个小时的卤虫卵，其孵化率再次降低了20个百分点。孵化进行79个小时的卤虫卵，其孵化率再次降低了37个百分点。     

冷冻等处理对不同孵化进程的卤虫卵存活率的影响

研究了冷冻、双氧水和干燥处理对处于不同孵化进程中的卤虫卵的存活率(孵化率)的影响。冷冻对未经孵化处理的卵的孵化率影响很小,冷冻1~8周,基本保持不变。孵化进行了3h的卤虫卵,冷冻8周后,其孵化率降低了10个百分点。孵化进行了6h的卤虫卵,冷冻8周后,其孵化率降低了31个百分点。孵化进行了9h的卤虫卵,冷冻8周后,其孵化率降低了40个百分点。处于不同孵化阶段的卤虫卵经冷冻处理8周后,再经3%双氧水处理10min和40℃干燥处理6h,其孵化率表现为不同的特点。未经孵化处理卵的孵化率基本保持不变。孵化进行了3h的卤虫卵,其孵化率再次降低5个百分点。孵化进行了6h的卤虫卵,其孵化率再次降低了20个百分点。孵化进行了9h的卤虫卵,其孵化率再次降低了37个百分点。     

中国卤虫卵孵化特性的研究

本文对山东埕口盐场、海南岛莺歌海盐场及青海柯柯盐湖天然采集的卤虫卵进行了孵化特性研究。埕口、莺歌海及柯柯的虫卵壳厚分别为9.7,11.4及13.2μm。在放入海水中进行孵化前上述三品系的卤虫卵分别在自来水中浸泡2,3及4小时能获得最佳孵化率。它们的最适孵化温度分别为25.6～28.5℃,27.0～30.0℃及27.0～33.0℃。最适孵化盐度分别为30,20及35％。孵化的同步性以“莺歌海”为最好,为6.4小时,“埕口”次之,为6.5小时,“柯柯”为7.4小时。 实验室内培养产卵后24小时内收集的虫卵用下列方法处理能终止虫卵的滞育状态:(1)埕口卤虫卵:浸泡于粗盐饱和溶液中2～3个月,孵化率可达91～94％。(2)莺歌海卤虫卵:浸泡于粗盐饱和溶液中2～5个月,孵化率可达80～91％。(3)柯柯卤虫卵:置于5℃2～3个月孵化率可达96～98％。用3％H_2O_2及3％甲醛溶液处理对终止滞育状态没有作用。天然采集的三个品系的卤虫卵用3％H_2O_2或3％甲醛溶液或用去壳溶液处理均可以提高孵化率。     

三品系中国卤虫卵的激活和提高孵化率的研究

在室温，４℃或－２５℃，用温度－ＣＯ２系列激活河北乐亭，青海尕海和山东羊口卤虫卵，并以空气和饱和ＮａＣｌ溶液系列处理作对照。其结果为：（１）乐亭卤虫卵经４℃－１００％ＣＯ２处理９０天，孵化率可达９３．３％；尕海卤虫卵经－２５℃－２０％ＣＯ２处理６０天，孵化率可达９０．２％等，而羊口卤虫卵孵化率提高幅度不大。（２）用ＯＣ２处理乐亭卤虫卵时，无论在室温或４℃－１００％ＣＯ２时，其孵化率上升趋势都比空气     

评价卤虫卵质量的一种新方法——出虫量

卤虫卵是培育海水鱼虾蟹苗重要的生物活性饵料，具有营养丰富、不饱和脂肪酸含量高，使用保存方便等特点。评价卤虫卵质量高低的传统指标有孵化率和孵化量，孵化率足指一百粒卤虫卵所能孵出的无节幼体只数。优质卤虫卵孵化率可达到90％以上：孵化量是指每克虫卵所能孵出的尢节幼虫总千重（毫克），     

卤虫卵孵化强化剂的初步研究

对不同品系的低孵化率卤虫卵进行了孵化对比试验，分为试验组和对照组，其中试验组添加孵化强化剂与对照组进行同等条件的试验，2组对照组的孵化率分别是66．8％、64．9％，试验组的孵化率分别是84．3％、81．5％增幅超过15个百分点，说明这种针对低孵化率卤虫卵研制的强化剂有效可行，可做进一步推广试验。     

卤虫卵品质与育苗成活率

由于条件所限,苗场对卤虫卵的质量鉴定往往只测定孵化率,依据孵化率的高低来判断卤虫卵的好坏,并且决定是否采用。实践证明,光测孵化率还不能证明卤虫卵的好坏,孵化率仅仅是一个方面。因为笔者就遇到过一种卤虫卵孵化率高达 90％,虾苗却 90％以上都死亡的情况。关于这一点,笔者曾与多位育苗同行讨论过,同行也深有感触,只是苦于没有有效的手段来鉴别卤虫卵的品质。 　　虾、蟹育苗都要用到卤虫无节幼体,虾、蟹苗 (幼体 )的营养完全依靠卤虫无节幼体,若卤虫无节幼体营养缺乏,必然影响到虾、蟹育苗的成活率。罗氏沼虾育苗死亡高峰…     

一种新型聚维酮碘制剂对卤虫卵及无节幼体的活体消毒试验

为了解一种新型的聚维酮碘制剂对卤虫卵及无节幼体的消毒杀菌效果,研究了该聚维酮碘制剂对卤虫卵和无节幼体的毒性以及对3种不同产地卤虫卵孵化率的影响,并进行了卤虫活体和孵化水的灭菌试验。结果显示,该聚维酮碘制剂在极高浓度(20000 mg/L)下,长时间(60 min)浸泡对市售卤虫卵孵化率无影响,并且未引起卤虫无节幼体死亡,毒性极低;试验分离到市售卤虫携带的4种优势细菌,分别为Vibrio tubiashii、V.sinaloensis、V.anguillarum和Uncultured V.sp.,以浓度500 mg/L的该聚维酮碘制剂处理30min后,可将孵化水中的细菌几近全部杀死(细菌存活率为1.67%);在试验浓度(2 000 mg/L)下,聚维酮碘对渤海湾盐田卤虫卵和巴里坤盐湖卤虫卵的孵化率无影响,但浓度在500 mg/L及以上时,俄罗斯进口卤虫卵的孵化率显著下降。试验结果表明,该聚维酮碘制剂可以作为优良的卤虫消毒剂,建议生产上使用浓度为200~500 mg/L。     

卤虫卵孵化强化剂的生产工艺及应用研究

研制出卤虫卵孵化强化剂及其生产工艺,对天津塘沽盐田和新疆艾比湖的卤虫卵利用孵化强化剂进行了孵化对比试验,分为试验组和对照组,其中试验组添加孵化强化剂,在相同条件下与对照组进行对比试验。结果表明,添加Ⅰ型孵化强化剂的试验组,孵化率平均增幅高达16％,添加Ⅱ型孵化强化剂的试验组,孵化率平均增幅为5％,增幅显著,证明了孵化强化剂具有提高卤虫卵孵化率的功能。     

测定卤虫卵孵化率的简易方法

测定卤虫卵孵化率的简易方法孵化率是鉴别卤虫卵质量的重要指标之一，但对育苗生产厂家而言，一般缺少较精确的卤虫卵孵化率测定装置，故在购买卤虫卵时对孵化率的把握存在一定的难度，现介绍一种简易的卤虫卵孵化率测定方法，可解上述之忧。１．取样计数：取一无污迹租斑...     

4种常用消毒药物对棕点石斑鱼(♀)×鞍带石斑鱼(♂)受精卵孵化的影响

人工育苗中对受精卵进行消毒,可以很大程度上预防各种病原对受精卵的危害,防止病原体的垂直传播。但是,用化学药物消毒,总会对鱼的受精卵产生一定程度的毒害作用。因此,人工育苗中进行受精卵消毒处理时必须控制药物种类、药物浓度及消毒时间。本研究在(27.0±0.5)℃条件下,使用药物浸泡的方法,研究了4种常用水产消毒药物对珍珠龙胆石斑鱼受精卵[棕点石斑鱼(♀)×鞍带石斑鱼(♂)]孵化效果的影响。聚维酮碘、甲醛和二氧化氯的处理时间均为10 min,臭氧处理分1 min、2 min和3 min共3个梯度。使用SPSS 17.0软件对试验数据进行方差分析,结果表明,其受精卵的孵化率和畸形率与药物的浓度、处理时间呈负相关。甲醛和二氧化氯处理组与对照组的孵化率、畸形率差异显著;聚维酮碘处理组中25 mg/L、50 mg/L与75 mg/L各处理与对照组无差异,100 mg/L处理出现显著差异;臭氧处理组,0.3 mg/L处理中的各时间梯度间的孵化率和畸形率与对照组差异性不显著,0.5 mg/L、0.7 mg/L及1.0 mg/L处理中各时间梯度间差异极显著,0.5 mg/L处理2 min时,孵化率已极低,仅为4.14%,畸形率为50.00%。试验结果证明,在珍珠龙胆石斑鱼苗种生产中,其受精卵的适宜消毒药物、浓度范围及处理时间分别为:聚维酮碘20–70 mg/L处理10 min,臭氧0.3–0.5 mg/L处理1 min;二氧化氯、甲醛对受精卵刺激显著,而且对环境及人体有毒副作用,建议在生产中尽量不要使用。     

Influence of egg size on the growth,onset of feeding,point-of-no-return,and survival of unfed Oreochromis mossambicus fry

The variation in egg size within and between egg clutches of O. mossambicus, and the subsequent influence of mean egg size on growth, feeding incidence and survival of unfed fry were investigated.The individual egg sizes within 90% of the egg clutches examined were normally distributed and the coefficient of variation of egg size within clutches ranged from 7.4% to 15.4%. Fry emerging from the small, medium and large egg size groups reached their maximum length and weight at 9, 9 and 12 days after hatching, respectively. Maximum attainable fry length and weight were significantly correlated with egg size (r = 0.885 and 0.947, respectively, with P < 0.01).Egg size had little influence on the onset of feeding. Fry were capable of exogenous feeding within 6 to 7 days of hatching. Fry originating from small and medium egg size classes reached the point-of-no-return at 15–16 days after hatching compared to 21 days for fry from the large egg size class. The mean survival time (ST₅₀) of fry on their yolk reserves was significantly correlated (r = 0.923; P < 0.01) with their original mean egg weight and ranged from 9.5 days for fry hatching from 0.91-mg eggs to 21 days for fry from 1.93-mg eggs.     

镧对草鱼卵子孵化的影响

本文研究了La~(3+)对草鱼受精卵孵化的影响,结果表明:La~(3+)的最佳浓度范围为0.6～4.8mg/L,可提高孵化率9.7～19.4％     

重金属离子除去装置在中国对虾育苗生产中的应用

自行研制的高分子吸附剂装置，在两处中等规模的中国对虾育苗场进行了应用实验。结果表明，在其他条件一致的情况下，应用装置与使用自然海水育苗对比，卵子的孵化率平均提高１１．８％，无节幼体到蚤状幼体变态率平均提高１０．２％；应用装置与使用ＥＤＴＡ（２．０ｍｇ／Ｌ）比较，卵子的孵化率平均提高７．５％，无节幼体到蚤状幼体的变态率平均提高３．６％。     

Breeding and larval rearing of the camouflage grouper Epinephelus polyphekadion (Bleeker) in the hypersaline waters of the Red Sea coast of Saudi Arabia

This is the first report on the successful year-round natural spawning and larval rearing of Epinephelus polyphekadion (Bleeker) in captivity and under hypersaline water conditions of 42-43%₀ salinity in the Red Sea coast of Saudi Arabia. Although the fish spawned naturally once or twice a year during 1992-94 culture period, incorporation of cod-liver oil in the broodstock diet during the 1995 culture period enabled the fish to spawn continuously for 2-3 days in each month during March, April, May and August. The egg fertilization and hatching rates also increased during the 1995 spawning period. The egg fertilization rate varied from 90 to 100% with a mean of 96.5 ± 3.38%. The egg hatching rate varied from 70 to 95% with a mean of 83.1 ± 10.12%. The fertilized egg diameter averaged 757.3 ± 37.36 μm. There was a linear relation between the fertilized egg size and the egg hatching rate. The increase in the hatching rate relevant to the egg size was statistically significant (P < 0.01). The egg development time until hatching lasted for 19 h at 29°C. The newly hatched larval size ranged from 1.55-1.71 mm with a mean of 1.65 ± 0.052 mm in total length. The larval growth was slow in the early stages and the growth curve until metamorphosis showed a curvilinear pattern. Wide variations in larval size, range 22-47 mm with a mean of 33.40 ± 7.01 mm, were observed during the metamorphosis stage at day 50. No significant difference (P > 0.05) in growth and survival was observed between the larvae reared using white and grey coloured tanks. The larval survival up to metamorphosis was 1.6-4.7% with a mean of 2.98 ± 1.56% in the grey coloured tanks and 1.6-1.9% with a mean of 1.73 ± 0.16% in the white tanks. The results demonstrated the possibility of breeding E. polyphekadion under captive culture conditions. However, methods to improve the larval survival have to be pursued further for commercial farming of this species.     

Predicting haddock embryo viability based on early cleavage patterns

Haddock, Melanogrammus aeglefinus, is a serial spawning, marine gadid characterized by low survivorship during the early life history stages. The potential for predicting future survival to hatching based on cleavage patterns of early embryos (8–32 blastomere stages) was investigated in order to improve efficiency of early rearing practices. In 2001, data from 36 egg batches (>95% fertilization) suggested that hatching success was inversely related to the percentage of embryos with abnormal cleavage. Mean percentage of normal cleavage did not differ throughout the spawning season but variability was much higher for embryos from early and late batches than those collected during the middle of the spawning season. In 2002, abnormalities in blastomere cleavage for 12 egg batches were further categorized as (1) asymmetric blastomere arrangement, (2) inequality of blastomere size, (3) poor adhesion between blastomeres and (4) poor definition of blastomere margins. Results suggested that all four abnormalities were co-occurring, which prevented negative effects on hatching success from being attributed to a single abnormality. Incubation of embryos with only one type of cleavage abnormality suggested that low adhesion between blastomeres significantly reduced embryo viability, while asymmetry in blastomere arrangement did not. However, because cleavage abnormalities tended to co-occur, hierarchical multiple regression revealed that asymmetry could be used to accurately predict hatching success, even if reduction in embryo viability was due to abnormalities other than asymmetry. Analysis of additional cleavage abnormalities suggested that complete separation between blastomeres was indicative of a very poor egg batch and resulted in little or no hatching, while cellular outcrops had no negative effect on hatching success. Information from detailed studies such as these could be used to predict hatching success of individual egg batches, allowing time and resources to be allocated more efficiently in hatcheries.     

银白鱼人工繁殖受精卵附着介质筛选

为探索有利于银白鱼人工繁殖中的附着介质,提高孵化效率,选取4种受精卵附着介质(纱窗网、棕片、砾石、瓦片),开展了银白鱼人工繁殖试验,对不同产卵介质条件下银白鱼受精卵的孵化率、孵化时长进行了分析比较.结果表明,银白鱼人工繁殖受精率约为90％,采用4种介质的孵化率由高到低依次为:棕片(80％)、纱窗网(70％)、砾石(45...     

来自鳗鲡的二株益生菌适宜培养基的研究

用正交试验法,通过研究培养基基础成分、主要添加成分和无机盐对养殖鳗鲡(Anguilla japonica)肠道益生菌枯草芽孢杆菌(A40209CDC4)和少动鞘氨醇单胞菌(A31009NA)的生长影响,确定了优化的培养基。菌株A31009NA的优化配方为:蛋白胨1.0%,牛肉膏0.1%,食盐0.5%,酵母膏0.5%,葡萄糖1.0%,硫酸铵0.05%,MgSO4.7H2O 0.1 g/L,CuSO4.5 H2O 0.15 mg/L,MnSO4.H2O 1.5 mg/L,CoCl.H2O 0.15 mg/L;A40209CDC4优化培养基配方为:蛋白胨1.0%,牛肉膏0.1%,食盐1.0%,酵母膏0.5%,硫酸铵0.05%,MgSO4.7 H2O 0.1 g/L,MnSO4.H2O 1.5 mg/L,CoCl.H2O 0.15 mg/L,CaCl20.02 g/L。优化培养基与普通营养肉汤(蛋白胨1.0%,牛肉膏0.3%,食盐0.5%)培养对照试验结果表明,优化培养基有效地提高了细菌产量。     

Effect of hybridization on reproductive performance of Oreochromis karongae,Oreochromis shiranus and Oreochromis mossambicus

The study assessed the effect of hybridization on reproductive performance of Oreochromis karongae, Oreochromis shiranus and Oreochromis mossambicus for a period of 120 days. Number of eggs per batch, number of females spawned, relative fecundity, egg size, hatching period, hatchability and hatchling survival were assessed. The results revealed higher number of eggs per batch and relative fecundity in the crosses where O. shiranus and O. mossambicus were females than female O. karongae. The results also revealed that egg size, hatching period, hatchability and hatchling survival were species specific. Significant differences were noted for number of eggs and larvae produced by the three species (p < .05). Interspecific and pure crosses for the same female species did not differ significantly for the number of eggs per batch, relative fecundity, egg size, hatching period, hatchability and hatchling survival. However, number of female spawned was found to be higher in the interspecific crosses of female O. karongae than in pure cross of O. karongae. Findings from this study suggest that hybridization can be used to improve reproductive performance of O. karongae as the females spawned increased, and it is a value addition in aquaculture management of indigenous species.     

A technique for delaying embryogenesis of vendace (Coregonus albula L.) eggs in order to synchronize mass hatching with optimal conditions for lake stocking

To improve the efficiency of stocking lakes with vendace (Coregonus albula) larvae, a technique for delaying egg hatching was developed. This synchronizes mass hatching with the development of suitable thermal conditions and food availability in the lake.Water temperatures were measured in Polish hatcheries and a mathematical model of the dependence of C. albula embryogenesis on incubation temperature was utilized to predict the possibilities of delaying egg hatching. Vendace hatching can be delayed by cooling the circulation water (to 1 or 2°C) during March and April. At the beginning of May, when lake conditions are optimal for stocking, the incubation temperature should be raised (at a rate of 1.5°C h^?1) to that of the water supply. This ensures mass hatching of strong, normally developed larvae within 2–3 days. This technique facilitates both the delay of vendace hatching at minimal cost and the production of larvae on demand for lake stocking.