中国大鲵不同地理种群间杂交子一代幼鲵的生长

将不同地理种群的大鲵Andrias davidianus亲本进行人工杂交,获得子一代幼鲵,研究各杂交组幼鲵(实验组)和本地繁殖幼鲵(对照组)的体长、体质量和存活率。12个月的饲养结果表明:各组平均存活率为83.33%~98.33%;平均体长为20.33cm~25.15cm,增加15.83cm~20.65cm,增长率351.78%~458.89%;平均体质量为163.34g~240.15g,增加162.59g~239.4g,增长率21678.67%~31920%。各组的存活率、体长、体质量差异显著(P<0.05);实验组存活率与对照组差异显著,实验组间差异不显著;实验组体长、体质量与对照组差异显著,表明不同地理种群间大鲵杂交子一代幼鲵生长优于本地大鲵繁殖的子一代。因此,繁育幼鲵时应尽量避免本地种群间的繁殖组合。     

大鲵幼苗饲养增重效果研究

人工养殖大鲵幼苗100尾,分5组每组20尾,饲养时间从稚鲵开食至1龄末,共一年时间。在适宜的饲养环境下,幼鲵体重从出膜的0.27-0.33g经过1年的饲养达24.68～30.42g,1龄净增重达24.41～30.09g,1龄增重率达8826%～9118%。1龄内的幼鲵生长态势极为迅速,增重效果明显。     

提高大鲵人工繁殖出苗率的关键技术

为探索提高大鲵人工繁殖出苗率的关键技术,在大鲵亲本培育期间,通过投喂活体饵料以及调控水温、水流、光照等措施,促使大鲵亲本性腺同步发育,并且优化了人工催产、授精和孵化技术,解决了大鲵人工繁殖率低的问题。试验结果显示:2015年共培育亲本37尾,其中35尾(雌鲵19尾,雄鲵16尾)性腺发育良好;催产后,2批共19尾雌鲵全部产卵,共收集卵9 157粒,产卵率为100%;人工授精24 h后,卵的受精率达85.6%;经35~38 d孵化,平均孵化出苗率为72.0%,远高于通常情况下人工繁殖的平均水平(5%~10%)。     

投喂死饵和活饵对大鲵生长性能的比较

<正>目前,大鲵人工养殖所投喂的饵料多以鱼块为主,以鲜活小杂鱼虾、蛋白质饲料等为辅。本试验探究了投喂死饵和活饵对大鲵生长性能的影响,对不同饵料条件下大鲵的生长情况进行对比分析,以期为大鲵高效健康养殖提供参考和借鉴。一、材料与方法1.大鲵成鲵体长(30.50±2.00)厘米,体质量(0.29±0.02)千克,体质健壮,活动能力强。成鲵养     

关于大鲵外鳃脱落期延长的探讨

正大鲵(Andrias davidianus)为隶属于隐鳃鲵科(Cryptobrachidae)大鲵属(Andrias)的有尾两栖动物,具有两栖类共有的变态发育过程。大鲵脱鳃期又称变态期,是指大鲵孵化出膜后生长到1龄左右时外鳃开始萎缩脱落,逐渐由鳃呼吸转变为肺呼吸的阶段。变态期除全长、体重增加外,最主要的特征是外鳃逐渐脱落,转变为以肺呼吸为主,皮肤辅助呼吸。笔者在同一批大鲵养殖过程中,发现10余尾大鲵年龄接近4龄而外鳃仍未     

湖南张家界大鲵养殖规模首次突破百万尾

<正>最近,从张家界市大鲵保护与发展科了解到,2014年湖南省张家界市大鲵养殖规模将首次突破100万尾大关,全市大鲵养殖量到达103.4万尾。据统计,2014年张家界市完成商品鲵加工销售9.86万尾,人工繁殖大鲵幼苗30.7万尾,培育能繁亲本1.73万尾,全市开发大鲵深加工产品95个。配套饵料鱼养殖基地3241.5亩山塘水库和79口网箱,已经提供饵料鱼600吨。大鲵养殖重点乡镇53个,千尾以     

复合益生菌对幼鲵生长及免疫指标的影响试验

本研究旨在研究复合益生菌对幼鲵生长及免疫指标的影响。随机选取体质健康、体重100g/尾左右的2龄幼鲵，分别添加占基础饵料重量0.20%、0.40%、0.60%的配比复合益生菌进行拌料投喂试验，并设置空白对照组，每组设置三个重复组，共12组，试验期180d。试验结束时测定各组大鲵的生长及摄食指标、血液生理生化指标及血清抗氧化酶及非特异性免疫指标，结果显示三个试验组大鲵终末体重、平均增重率、特定生长率均显著高于对照组，指标数据说明以复合益生菌拌料投喂有利于大鲵的生长；中剂量组及高剂量组大鲵血液中的总蛋白(TP)及白蛋白(ALB)含量均显著高于对照组及低剂量组；试验组大鲵血清中酸性磷酸酶(ACP)均高于对照组，这显示出复合益生菌拌料投喂对大鲵的非特异性免疫有促进作用；中剂量组及高剂量组大鲵血清中超氧化物歧化酶(SOD)活性均显著性高于对照组及低剂量组。结果表明，复合益生菌(芽孢杆菌、酵母菌、乳酸菌)添加日常饵料重量0.40%、0.60%的配比中剂量、高剂量组不仅能促进大鲵的生长发育，同时还能促进大鲵对营养物质的吸收利用，从而增强体质，提升疾病抵抗力。     

野生中国大鲵的人工驯养

对野生中国大鲵幼鲵和成鲵驯养过程中的几个重要方面提出了见解,内容包括苗种培育(苗种的运输、挑选、消毒、日常管理、饵料、幼鲵脱鳃期的管理、幼鲵的病害)和成鲵养殖(养殖模式、日常管理、饵料、病害),还有野生大鲵从自然环境条件进入人工养殖环境条件后的应激反应.     

大鲵规模化养殖生产试验研究

文中对秦岭北麓渭南市华州大鲵驯养繁育基地分别对4000尾稚鲵相同饲养条件下的增重、肥满度以及58尾亲鲵的产前、产后体重增长情况进行了研究。研究表明：幼鲵在一龄时增长速度最快;亲鲵在产前、产后的体重一直在增加;同时,通过对试验阶段饲养条件和技术的探索,提出了更为准确、合理的科学养殖方法。为大鲵规模化养殖生产做了前期准备工作。     

关于提高大鲵Megalobatrachus davidianus(Blancgard)稚鲵养殖成活率技术的探讨

大鲵俗称娃娃鱼,为我国特有的大型两栖珍稀动物,既有观赏、科研价值,又有食用、药用等价值.随着大鲵自然资源的保护和人工繁殖养殖的成功,大鲵养殖热不断升温,目前,这一品种的养殖已成为我国淡水养殖中的一个"热点".大鲵稚鲵期是指刚孵化出苗到脱鳃的两年时间,稚鲵期管理不善,导致稚鲵及脱鳃变态后的幼鲵对环境适应能力差,对疾病抵抗力差,感染病害死亡,最终影响养殖成活率及经济效益.笔者通过对稚鲵养殖的实践,总结出了影响稚鲵成活率的原因,并通过技术创新,提高了稚鲵养殖的成活率达95%.     

A Comparison of Natural and Artificial Diets for Juveniles of the Australian Freshwater Crayfish Cherax destructor

Abstract Growth rates of juvenile yabbies Cherax destructor fed a variety of natural and an artificial diet were compared under controlled conditions. Newly independent (stage 3) juveniles were reared individually in 1-L pomades for 35 d. The best survival and growth were obtained on live zooplankton, frozen zooplankton, shrimp meal pellets and tubifex worms (survival, 100%; mean weights, 608, 444, 380 and 338 mg, respectively). Intermediate growth and survival was exhibited by crayfish fed chironomid larvae, snails and mussels (survival, 80–100%; mean weight, 138–169 mg). Juveniles fed trout muscle, beef heart and yabby tail gave very poor growth and survival (survival, 50–80%; mean weight, 50–55 mg). The use of shrimp meal pellets as a reference diet for juvenile yabbies is discussed.     

β-葡聚糖对亚东鲑幼鱼存活及生长的影响

在水温13~14 ℃下,将平均体质量(1.07±0.3) g的亚东鲑幼鱼养在100 cm×100 cm×60 cm圆形玻璃缸循环水系统中,密度为159尾/m^( 3) ,水深约40 cm,投喂添加0%、0.1%、0.2%、0.5%、 1.0% 、1.5%和2.0%β-葡聚糖的饲料饲养60 d,研究β-葡聚糖对亚东鲑幼鱼存活及生长的影响。试验结果显示,不同含量β-葡聚糖对亚东鲑幼鱼存活率差异不显著,均为100%;平均质量增长率0.5%试验组最大,显著高于其他各组( P <0.05),平均体长增长率0.5%试验组最大,与0.2%、0.5%、1.5%试验组之间差异不显著,显著高于其他各组( P <0.05),0%试验组平均体长增长率最小;特定生长率0.5%试验组最高,显著高于其他各组( P <0.05),0%试验组最低;肝体指数依次递减,0%试验组最大,与 0.1% 、 0.2% 和0.5%试验组之间差异不显著,但显著高于其他各组( P <0.05);肥满度0.1%、0.2%、 0.5% 、 1.0% 试验组之间差异不显著,显著高于其他各组( P <0.05),0%试验组最小;摄食率0.1%试验组最高,随着β-葡聚糖添加量增加依次递减,但各试验组之间差异不显著;食物转化率0.5%试验组最高,与1.0%、 1.5% 、2.0%之间差异不显著,显著高于其他各组( P <0.05),0%试验组最低。肠道脂肪酶、胰蛋白酶和淀粉酶活性均随β-葡聚糖含量增加呈先增后减变化趋势,说明β-葡聚糖能够提升肠道消化酶活性。综上所述,饲料中添加0.5%β-葡聚糖对亚东鲑存活与生长效果较好。     

Extension of nursery culture of Scylla serrata (Forsskål) juveniles in net cages and ponds

To address the preference of mud crab farmers for larger size Scylla serrata juveniles (5.0–10 g body weight or BW; 3.0–5.0 cm internal carapace width or ICW), a study was conducted to compare the growth and survival of crab juveniles (2.0–5.0 g BW; 1.0–3.0 cm ICW) produced a month after stocking of megalopae in net cages when reared further in net cages installed in earthen ponds or when stocked directly in earthen ponds. In a 3 × 2 factorial experiment, three stocking densities (1, 3 and 5 ind m⁻²), two types of rearing units (net cages or earthen pond) were used. Megalopae were grown to juvenile stage for 30 days in net cages set inside a 4000 m² brackishwater pond and fed brown mussel (Modiolus metcalfei). Crab juveniles were then transferred to either net cages (mesh size of 1.0 mm) or earthen ponds at three stocking densities. After 1 month, no interaction between stocking density and rearing unit was detected so data were pooled for each stocking density and rearing unit. There were no significant differences in the growth or survival rate of crab juveniles across stocking density treatments. Regardless of stocking density, survival in net cages was higher (77.11±6.62%) than in ponds (40.41±3.59%). Growth, however, was significantly higher for crab juveniles reared in earthen ponds. The range of mean BW of 10.5–16.0 g and an ICW of 3.78–4.33 cm obtained are within the size range preferred by mud crab operators for stocking grow‐out ponds.     

Partial and total replacement of fish meal with soybean meal and brewer's grains with yeast in practical diets for Australian red claw crayfish Cherax quadricarinatus

Three feeding studies were conducted to evaluate the effects of total replacement of fish meal (FM) with a combination of soybean meal (SBM) and brewer's grains with yeast (BGY) in diets for two separate strains of juvenile Australian red claw crayfish. In Experiment 1, three practical diets were formulated to be isonitrogenous (40% protein) and isocaloric (4.0 kcal available energy/g diet) and contained either 25%, 10%, or 0% fish meal. Variable percentages of SBM (35%, 46.8%, and 79.8%, respectively) and BGY-35 (0%, 30%, and 5%, respectively) replaced the fish meal. In Experiments 2 and 3, four practical diets were formulated to be isonitrogenous (40% protein) and isocaloric (4 kcal available energy/g diet) containing 24% or 0% fish meal. Diet 1 contained 24% fish meal, 23% SBM, and 0% BGY-35. A variable percentage of SBM (56.75%, 47.75%, and 40.75%, respectively) and BGY-35 (10%, 20%, and 30%, respectively) replaced the fish meal in the remaining three diets.

In Experiment 1, after 8 weeks, juvenile red claw fed all three diets had no significant difference (P>0.05) in final weight, percentage weight gain, or survival, which averaged 7.90 g, 3848%, and 83%, respectively. In Experiment 2, after 8 weeks, juveniles fed all four diets had no significant difference in final weight, percentage weight gain, or specific growth rate which averaged 11.46 g, 977%, and 3.08%/day, respectively. Percentage survival was not significantly different among treatments and averaged 79%. In Experiment 3, after 8 weeks, juvenile red claw fed all four diets had no significant difference in final weight, percentage weight gain, or specific growth rate which averaged 16.22 g, 457%, and 2.34%/day, respectively. Percentage survival was not significantly different among treatments and averaged 98%.

These results indicate that fish meal and shrimp meal can be totally replaced with soybean meal and BGY in diets for juvenile red claw crayfish. This may allow for less expensive diets by red claw producers, which may increase profitability.     

Effects of light intensity,stocking density and temperature on the air-bubble disease,survivorship and growth of early juvenile seahorse Hippocampus erectus Perry, 1810

This investigation examined the effects of light intensity, stocking density and temperature on the air-bubble disease, survivorship and growth of early juveniles (2–30 days old) of seahorse Hippocampus erectus Perry. The juveniles in the 100 lx treatment had the highest air-bubble disease rate of 20.8 ± 6.2% and the juveniles in the 500 lx treatment had the highest survival rate of 84.4 ± 5.5%. The juvenile seahorses cultured in the 1500 lx treatment had the highest final wet weight of 0.13 ± 0.02 g and the highest final standard length of 4.54 ± 0.37 cm (F_{7, 144}=57.406, F_{7, 144}=12.315, P<0.05). There was no significant effect of stocking density on the air-bubble disease rate (F_{6, 21}=1.893, P=0.126). The juveniles cultured in the 1 ind L⁻¹ had the highest wet weight increment of 0.134 ± 0.031 g, but juveniles in the 2 ind L⁻¹ had the highest standard length increment of 3.17 ± 0.30 cm (F_{6, 126}=34.902, F_{6, 126}=11.726, P<0.05), and juveniles cultured in the 1.5 ind L⁻¹ had the highest survival rate of 86.1 ± 4.6%. The result of interaction of light intensity and temperature showed that the juveniles cultured in the 1500 lx and 26 °C had the highest weight gain and specific growth rate of 3791.17 ± 323.97% and 13.07 ± 0.18, respectively, and the lowest air-bubble disease rate of 9.3 ± 4.5% occurred in the 1000 lx and 26 °C (F_{8, 36}=12.355, P<0.05).     

Grow-out of sandfish Holothuria scabra in ponds shows that co-culture with shrimp Litopenaeus stylirostris is not viable

We examined the potential for producing the large numbers of sandfish (Holothuria scabra) needed for restocking programmes by co-culturing juveniles with the shrimp Litopenaeus stylirostris in earthen ponds. Our experiments in hapas within shrimp ponds were designed to detect any deleterious effects of sandfish on shrimp, and vice versa. These experiments showed that a high stocking density of juvenile sandfish had no significant effects on growth and survival of shrimp. However, survival and growth of sandfish reared with shrimp for 3 weeks were significantly lower than for sandfish reared alone. Increased stocking density of shrimp also had a significant negative effect on survival and/or growth of sandfish. A grow-out trial of juvenile sandfish in 0.2-ha earthen ponds stocked with 20 shrimp post-larvae m^− 2, and densities of sandfish between 0.8 and 1.6 individuals m^− 2, confirmed that co-culture is not viable. All sandfish reared in co-culture were dead or moribund after a month. However, sandfish stocked alone into 0.2-ha earthen ponds survived well and grew to mean weights of ∼ 400 g within 12 months without addition of food. The grow-out trial demonstrated that there is potential for profitable pond farming of sandfish in monoculture. Further research is now needed to identify the optimal size of juveniles, stocking densities and pond management regimes.     

GROWTH OF WHITE STURGEON (Acipenser transmontanus) UNDER HATCHERY CONDITIONS

White sturgeon juveniles were raised for 10 months posthatch under various regimens of feeding, water temperature, and stocking density. Transition to external feeding in larvae occurred 9 to 11 days posthatch and was accompanied by major changes in allometric growth and larval behavior. Condition factor, hepatosomatic index, and survival rate varied significantly throughout the rearing period in the 4 progenies investigated. Growth in body weight for all progenies was largely dependent on water temperature and feeding. On the average, fingerlings raised on natural diets (brine shrimp and tubifex, followed by ground fish) grew 6% of their body weight per day, whereas fingerlings fed artificial pelleted diets (Oregon Moist Pellets) or a mixture of pelleted and natural feeds grew 1–4% per day. Certain individuals (20% of population investigated), however, established a strong feeding performance on artificial diets and exhibited twice the growth rate of fish raised on natural diets; these fish reached a mean body weight of 282 g at 10 months post-hatch. Assuming more efficient procedures are developed for weaning this fish onto artificial diets, the white sturgeon has demonstrated a potential for use in intensive grow-out systems.     

Effects of Dietary Short-chain Fructooligosaccharides on Intestinal Microflora, Survival, and Growth Performance of Juvenile White Shrimp, Litopenaeus vannamei

Abstract.— Five groups of juvenile white shrimp, Litopenaeus vannamei , in triplicate were separately fed a compound diet with additional short-chain fructooligosaccharides (ScFOS, Profeed^® 95%) 0, 0.4, 0.8, 1.2, or 1.6 g/kg dried diet for 8 wk to investigate the effects of ScFOS on the intestinal microflora, survival, and growth performance of the shrimp. The juvenile shrimp with around 0.17 g of initial body weight were divided into 30 per tank and reared in a standard water recirculation system at 28 C. The shrimp were fed five times a day. At the end of experiment, the shrimp were weighed and their intestinal samples were analyzed for the amounts of Vibrio parahaemolyticus, Aeromonas hydrophila, Lactobacillus sp. , and Streptococcus faecalis using selective agar. The results showed that the shrimps' weight gain and specific growth rate increased with the increment of dietary ScFOS, while their feed conversion ratio decreased. The result was the best when an additional ScFOS 0.4 g/kg dried diet was used.     

Evaluation of Live Feeds for Larval and Postlarval Mahimahi Coryphaena hippurus

Live hatchery feeds were assayed for fatty acids (FA), amino acids (AA), and their ability to support growth and survival of larval and postlarval mahimahi Coryphaena hippurus at two different hatchery stages. Euterpina acuritrons copepods (C), mahimahi yolk-sac larvae (YSL), Artemia parthenogenica brine shrimp nauplii (BSn), A. parthenogenica juveniles (BSj), and Brachionus plicatilis rotifers (R) were assayed, using several enrichment media. There was little difference in AAs among feeds.
Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were about 10 times higher in YSL than in their feeds. This explains previous findings where first stage larval survival (0–9 days) was not affected by feed HUFA levels. Second stage survival was significantly higher when larvae were fed copepods. Enrichment with 100 ppm SuperSelco greatly improved the survival of larvae that were fed brine shrimp. The even higher omega-3 fatty acids found in copepods appear to be important for survival of larvae under more stressful conditions.
Brine shrimp juveniles enriched with SuperSelco are a good food for postlarval mahimahi. Yolksac larvae of mahimahi are an even better food, promoting faster growth at less cost, for large scale mahimahi aquaculturists. Different batches of yolksac mahimahi larvae varied by a factor of 10 in their concentration of DHA, but always had the highest level of DHA as much as 40% of total fatty acids (FAs). These "high HUFA" batches of YSL also had the highest levels of EPA and total fatty acids. The data suggest that climate and broodstock age may have considerable influence on larval nutrition.