花人繁子代亲鱼个体生殖力研究

比较了人工繁殖的一冬龄、二冬龄花亲鱼和野生亲鱼(2-3龄)的个体生殖力。结果表明,人繁子代培育的花亲鱼一冬龄可达性成熟,但在同体长范围内(18-21 cm),野生亲鱼和人繁一冬龄花亲鱼的个体相对生殖力差异极显著,人繁一冬龄和人繁二冬龄个体相对生殖力差异极显著,而野生亲鱼和人繁二冬龄亲鱼的个体相对生殖力差异不显著。研究表明,人繁二冬龄花的个体绝对生殖力在0.6-4.2万粒/尾,平均为2.05万粒/尾,相对生殖力为8.07-17.53万粒/kg,平均为137粒/g;而人繁一冬龄花的相对生殖力仅为0-5.87万粒/kg,平均为34粒/g。研究认为,花人工繁殖子代亲鱼在池塘培育条件下完全可以进行人工催产。     

北盘江光照库区花人工增殖技术研究

主要研究了北盘江光照库区花的人工增殖放流技术。通过4年的实践,总结出花的亲本采集驯养、亲鱼培育、苗种繁育等关键技术及各阶段的日常管理措施、常见鱼病的防治方法等方面的知识。为花及其他鱼类的人工增殖放流提供参考。     

花提早人工催产及孵化试验

2008年4月16-28日在浙江湖州地区进行了花于水温15℃条件下的人工催产生产性试验。用常规催产剂和方法,催产花亲鱼540尾,其中雌亲鱼355尾、雄亲鱼185尾。试验结果表明:排卵率为91.5%,催产效应时间为29.5 h,群体排卵时间为2.5 h;受精率为98.7%;孵化鱼苗(下塘鱼苗)380万尾。与常规生产水温17～18℃以上催产情况比较,在水温15℃条件下,花也完全可以进行人工催产;除效应时间和孵化时间延长及卵膜难以溶解外,其排卵率、受精率、群体排卵时间和孵化率等均无明显差异。     

花人工繁殖实验

<正>为了丰富福建省淡水养殖品种,我场于2013年引进花亲鱼200组(雌、雄亲鱼各100尾),后备亲鱼1000尾(1冬龄,体长8~10厘米),进行苗种繁育和池塘养殖示范推广。在2014年人工繁殖实验的基础上,2015年进行人工繁殖批量生产,人工催产2批,共生产水花苗242.5万尾。现总结如下:一、材料与方法1.亲鱼选择催产前一天,将花亲鱼关进网箱进行亲鱼筛     

蟹池放养花亲鱼繁殖育种试验

正花在本地区作为混养品种之一,一直受到生产者的青睐。以往花鱼种主要靠外购,成本高,放养成活率低。2017年笔者在蟹池放养花亲鱼,尝试自产和培育鱼种,取得了较好的效果,现将结果总结如下。一、材料与方法1.池塘条件与设备池塘面积18.6亩,平均水深1.5米,水源充足,排灌方便,用水符合渔业用水标准,安装3千瓦微孔增氧设备一套。2016年12月初池塘水排干,冻晒。2017年2月初加水     

花[鱼骨]人工繁殖技术的研究

本文主要研究了花[鱼骨]的繁殖生物学和人工繁殖技术。经过实验摸清了花的性成熟年龄和成熟最小型,性腺的发育状况,花的繁殖力、产卵时间和水温、雌雄鉴别等;比较了不同催产药物对花的催产效果,2008年催产率达100%,受精率95.3%,孵化率95%,获鱼苗14.12万尾。     

花(鱼骨)人繁子代亲鱼的人工催产试验

试验设计3个温度16.0~17.0℃、18.5~20.5℃和22.0~24.0℃,采用3种催产剂组合催产,对花人繁子代亲鱼进行催产试验。试验表明:用HCG 1000 IU/kg LRH-A21.2μg/kg、DOM5.0 mg/kg LRH-A21.2μg/kg、PG 3.0 mg/kg LRH-A21.0μg/kg组合均能成功催产人繁子代花亲鱼。其中,在18.5~20.5℃和22.0~24.0℃催产中,DOM 5.0 mg/kg LRH-A21.2μg/kg具有较短的催产时间和较高的催产率、受精率。人繁子代亲鱼在池塘培育条件下完全可以进行人工催产,花可以像“四大家鱼”一样进行全人工繁殖。     

鲢鳙草亲鱼在电厂温流水中培育的新方法

利用电厂排放的敞热循环水进行鲢鳙草亲鱼提早培育和繁殖,是北方寒冷地区就地解决早产鱼苗的重要途径。所谓提早培育,主要指的是利用温流水提前进行的产前提温饲养。我场是利用电厂温流水逃行家鱼人工繁殖的大型鱼苗场,从1992年开始采取新的培育方法,即:鲢鳙亲鱼产前用配合饲料驯化培育;草亲鱼采用“由精转青”进行培育;产后亲鱼全部移到自然池塘常规饲养的方式,取得了良好的效果。1992、1993两年鲢鳙草亲鱼于4月30日产卵,创造了北方寒冷地区家鱼人工繁殖最早产卵的记录。用这种新的培育方法,两年共培育鲢鳙草亲鱼980组,催产882组,亲鱼成熟率90％;产卵738组,产卵率84％;共产卵4.4亿,出水花2.9亿尾。现把有关情况介绍如下。     

介绍一种家鱼催产的新设备

在家鱼人工繁殖工作中，人工授精具有受精率高和节约雄鱼等优点，在生产上被广泛采用。使用传统的催产设备——产卵池进行催产，亲鱼需要编号，在第二次注射和进行人工授精时都必须将亲鱼从产卵池中捕起并装入担架内才能操作。这样既多花劳力，亲鱼又容易受伤。     

陶瓷管道诱导大弹涂鱼产卵实验

本文报道了人工制作的陶瓷管道诱导大弹涂鱼产卵的实验结果。未经激素催熟的亲鱼放人产卵池内7—12d未见产卵。经一次激素注射催熟的亲鱼放人产卵池内第3天开始在管道内交配产卵和受精,未能产卵雌鱼的卵母细胞开始退化吸收。不同产卵池中管道的产卵率差别很大。卵子粘附在管道不同部位的数量和受精率均不相同。强迫配对的亲鱼虽有产卵,但卵子不受精。     

台湾海峡野生牙鲆繁育技术

本文介绍2007年和2008年的12月下旬,选用捕自台湾海峡的野生牙鲆（Paralichthys olivaceus）（2～6kg／尾）作为亲鱼,约经45d左右人工驯养、促熟达到性成熟,在产卵池中自然产卵受精。经过一系列鱼苗培育操作过程,获得健康的苗种。     

Assessing sexual maturity of feminized Japanese eel Anguilla japonica by measuring eye size

For efficient production of Japanese eel Anguilla japonica eggs, knowledge of the status of the sexual maturity of potential broodstock females is important because this status directly influences the time required to produce mature eggs by successive hormone doses. Here we apply an eye index (relative eye size) to evaluate the gonadal status of feminized A. japonica, which were induced by administration of estradiol-17β. Examination of gonad somatic and eye indexes of 267 feminized eels, cultivated for 12–56 months, revealed a significant correlation between these two indexes. Artificial maturation of 35 feminized eels showed that the number of hormone injections administered before ovulation was significantly lower as the eye index score increased, indicating availability of this noninvasive method of predicting sexual maturity of feminized eel. There was no correlation between eye index and fertilization rate, hatching rate, or larval survival rate, suggesting that sexual maturity before hormonal treatment does not affect egg quality.     

The Sheepshead Minnow Cyprinodon variegatus—A Major Pest in Experimental Mariculture of the Gulf Killifish Fundulus grandis

In an experimental Fundulus grundis hatch and growout system at the Cedar Bayou Mariculture Laboratory, egg-to-harvested-fry survival rate of F. grundis was inversely related to percentage of Cyprinodon variegatus fry present ( P < 0.05). Competition for food and space was noted in growout ponds, and high mortalities of F. grundis fry and adults occurred in mixed holding containers as a result of the agonistic behavior of C. variegutus . The hardiness and aggressiveness of the sheepshead minnow, its ability to enter water supplies as small prolarvae, its early sexual maturity, and rapid increase in ponds make it a significant pest in mariculture.
Control measures for C. variegutus include screening incoming water; hand-sorting contaminated broodstock and fry; and draining, drying, and refilling infested ponds to allow drought-resistant eggs to hatch, then draining and drying again.     

Natural Spawning of Captive Bigeye Scad Selar crumenophthalmus in Hawaii

Abstract.— Juvenile bigeye scad Selar crumenophthalmus were caught from the wild by hook and line and reared over 3 yr to establish a spawning broodstock of this species. The size at first maturity for captive males and females was 19-cm and 25-cm fork length (FL). Natural spawning of captive individuals occurred during the first year in captivity. The broodstock were observed to spawn repeatedly throughout their second and third years in culture. This species is a multiple spawner producing approximately 96 × 10³ to 121 × 10³ eggs/spawning group, 5 to 10 times per year. Stocking densities of 1–8 individuals/m³ were found to be suitable for natural spawning to occur. Collectively, the results indicate that this species exhibits notable potential for artificial propagation.     

Effects of dietary protein level on spawning performance of Nile tilapia (Oreochromis niloticus) broodstock reared at different water salinities

Effects of dietary protein level and water salinity on spawning performance of Nile tilapia broodstock and growth of their larvae were studied. Four isocaloric (400 kcal/100 g) diets containing 25%, 30%, 35% and 40% crude protein were prepared. The diets were fed to broodfish (25.7 g) reared at three water salinities (0‰, 7‰ and 14‰) at a female/male ratio of 3:1, to satiation twice a day for 195 days. The size at first maturation increased with increasing dietary protein at all salinities. At 25% and 30% protein levels, broodstock reared at 0‰ reached their sexual maturity at bigger sizes than those reared at 7‰ and 14‰. At 0‰, spawning intervals were not significantly affected by dietary protein levels. At 7‰ and 14‰, spawning intervals significantly decreased with increasing dietary protein level. Spawning frequency and number of eggs per spawn were increased with increasing dietary protein level. The total number of spawnings per female and absolute fecundity were better in fish fed 40% protein in freshwater than at 7‰ and 14‰ salinity. The relationship of dietary protein and water salinity on egg size was significant, but showed irregular patterns. The chemical composition of broodstock muscles, eggs and fry were not significantly affected by dietary protein and water salinity, except for body water and crude protein of broodstock which were significantly affected; but showed irregular trends. At each water salinity, egg hatchability was linearly increased with increasing dietary protein level. Eggs produced from broodstock fed 25% protein at 7‰ and 14‰ needed more time for hatching and yolk-sac absorption and resulted in poorer larval weight than those reared in freshwater. Fry growth was improved with increasing protein level at all salinities. This result revealed that 40% dietary protein is required for optimum spawning performance of Nile tilapia reared at 0‰, 7‰ and 14‰ salinity. It also indicated that spawning performance and larval growth were better in freshwater than at 7‰ and 14‰.     

基于卵黄蛋白原基因表达的水丝蚓促熟南美白对虾研究

针对传统海产亲虾饵料易感染或携带与对虾共患病毒,给育种和苗种繁育工作带来巨大生物安全隐患的问题,以淡水品种水丝蚓作为替代饵料进行南美白对虾亲虾催熟试验,并以卵黄蛋白原基因的表达水平变化验证饵料的催熟效果。设水丝蚓、水丝蚓组合饵料、商业亲虾饲料及传统沙蚕组合饵料等4个饵料组合,分别投喂南美白对虾后备亲虾,测定繁殖性能相关参数,并通过荧光定量PCR技术对各亲虾肝胰腺和卵巢中VTG的表达水平的变化进行了追踪研究。结果显示,水丝蚓组的性腺增重最高,达1 475%,连续产卵率最大,平均为72.08%,与传统沙蚕组合饵料组无显著差异性(P0.05)。南美白对虾肝胰腺和卵巢组织中均存在VTG mRNA,在肝胰腺和卵巢中均呈先上升后下降的表达模式;VTG mRNA的表达量能够一定程度上反映对虾的繁殖性能,有希望发展成为亲虾繁殖性能选育指标;水丝蚓在促进亲虾性腺发育方面效果较传统沙蚕饵料组合好,在改善亲虾产卵效果方面基本与沙蚕组合相当,可作为沙蚕替代饵料用于南美白对虾的亲虾强化培育和催熟。     

Observations on growth, sexual maturity and spawning performance of pond-reared Penaeus merguiensis

This 12‐month preliminary study investigated the development of sexual characters, primary sexual maturity, ovarian maturity and spawning performance of pond‐reared Penaeus merguiensis in relation to culture conditions in south‐east Queensland, Australia. Post‐larvae of P. merguiensis were produced and cultured in two 60‐m³ tanks during the first 14 weeks. Before winter, they were harvested and stocked in three different overwintering facilities: a 200‐m² covered pond, two 60‐m³ outdoor tanks and a 15‐m³ indoor, recirculated tank at a stocking density of 10 individuals m^?2. The development of sexual characters was found to be similar to that reported previously in wild P. merguiensis. Males matured at younger ages and smaller sizes than females. Overall, the average size at primary sexual maturity of pond‐reared P. merguiensis was 23.1 mm carapace length for males (possessed spermatophores) and 29.3 mm for females (being impregnated). Water temperature and the availability of natural food strongly influenced prawn growth, maturity rate and their subsequent spawning performance. Growth, maturity rate and spawning performance of prawns in the covered pond were significantly higher than in the other overwintering facilities. Prawns started mating at 6–7 months, reached full ovarian maturation and spawned as early as about 8 (peaked at 9–11) months from hatching, producing high fecundity and viable larvae. There was a strong relationship (P < 0.001) between prawn size and fecundity. The results of this study suggest a potential for using pond‐reared broodstock P. merguiensis for hatchery production and for domestication or selective breeding programmes.     

Economics of joint production of sturgeon (Acipenser transmontanus Richardson) and roe for caviar

Costs, revenues, net income and rate of return on investment of rearing sturgeon for production of both meat and roe for caviar are analyzed by a computer simulation model for three sizes of hatchery-growout operations: capacities for handling 5, 10, and 15 broodstock. Biological relationships regarding growth, feed consumption, sexual maturity, and mortality interact with management decisions about stocking density, age at which part or all of the fish are marketed, and size of plant to yield the economic performance measures under several scenarios. Spline functions are used to estimate functional relationships between growth (weight) and age while the mortality is described by logistic functions. The biological data were obtained from the University of California, Davis, Aquaculture and Fisheries Program, and various commercial sturgeon producing firms in California. When sturgeon roe prices are less than $331 per kg, the firm receives a greater rate of return on investment by marketing all production fish at 18.5 months of age. With roe prices greater than $331 per kg, higher rates of return on investment are obtained by retaining female fish through sexual maturity (from 6 through 10 years of age) and harvesting the roe as well as the meat. Results are presented under the specification that all but 4000 fish are sold at age 18.5 months. Two thousand females from those 4000 fish are raised beyond 36 months of age for roe production. Economies of scale were exhibited as the firm's capacity expanded to 15 broodstock.     

Response to individual selection for age at sexual maturity in Atlantic salmon

Atlantic salmon (Salmo salar) that mature sexually at 1 year of age (as parr or precocious males), at 4 years of age (after two winters in the sea) and at 5 years of age (after three winters in the sea) were used to study response to individual selection for age at sexual maturity. Six mating groups were made: between fish of the same age (4 × 4 and 5 × 5); reciprocal matings between 4- and 5-year-old fish (4 × 5 and 5 × 4); and matings between 1-year-old precocious males and 4- and 5-year-old females (1 × 4 and 1 × 5). Parental age at sexual maturity was found to influence markedly the offspring age at sexual maturity. The heritability for age at maturity in the sea was estimated at 0.48 ± 0.20 from the offspring—dam regression. It is concluded that there is considerable opportunity to alter the age at sexual maturity in Atlantic salmon through selection. Evidence was found that maturation of parr is a heritable trait and that it is independently inherited from maturation in the sea.     

Oocyte and embryo quality in Crassostrea gigas (Portuguese strain) during a spawning period in Algarve,South Portugal

Egg quality is one of the most important factors determining larval viability. The study of oocytes released by `wild' broodstock will contribute to the definition of quality criteria applied to hatcheries as well as being an indicator of the oyster reproduction potential and aquaculture ongrowing systems. The aim of this study was to determine the relationship between condition of Crassostrea gigas spp. angulata (Portuguese strain) from `wild' broodstock (condition index, gonadal maturity and number of oocyte released), oocyte biochemistry and hatching rate of eggs during the spring/summer of 1995. Stages of gonadal maturity and condition index indicated that natural spawning of this species occurred between April and August with the highest spawning intensity occurring in June. Analyses demonstrated that C. gigas oocyte organic matter consist of 44–74 % proteins, 16–38 % lipids and 7–12 % carbohydrates. A significant relationship was observed between some biochemical parameters – organic matter and lipid content – and broodstock condition index and hatching rate. It seems that these two oocyte parameters (organic matter and total lipids) could be used to define quality of oocyte and thus larval viability. The oocyte protein content was also found to be associated with broodstock and larval quality. In summary, these data are a contribution to the knowledge of the reproductive cycle of oysters in Europe and may be useful in improving hatchery management of this species.