虹鳟养殖技术之一利用地下井水室内工厂化养殖金鳟技术

金鳟作为一种新兴的名贵养殖品种,正逐步受到人们的关注。2006年,笔者改造原有的对虾育苗池,利用地下井水室内工厂化养殖金鳟,经过近8个月的时间,在总面积为480m2的养殖池中共生产成鱼16t,且成鱼平均规格达到体重357.4g/尾,养殖成活率为90%,获得了良好的经济效益。     

Comparison of brown trout (Salmo trutta) reared in fresh water and sea water to freshwater rainbow trout (Oncorhynchus mykiss): II. Phosphorus balance

Brown trout and rainbow trout (average weight 100 g) were reared in fresh water at 12 °C under the same conditions before transferring brown trout to sea water, in order to compare phosphorus utilisation in both species. Apparent phosphorus availability, orthophosphate excretion and phosphorus accretion in the fish were directly determined. Thus, actual phosphorus mass balance was built. Rainbow trout raised in fresh water had a higher phosphorus retention coefficient (maximum 50 %) than brown trout reared in fresh water (maximum 45 %). Transferring brown trout to sea water induced a reduction in phosphorus retention (maximum 39 %). Orthophosphate excretion, ranging 7–20 mg phosphorus per kg wet weight per day, represented 10–20 % of ingested phosphorus. Phosphorus availability was lower in brown trout raised in sea water (65 %) than brown trout raised in fresh water (76 %). Phosphorus balance measurements showed that 90 to 98 % of phosphorus flow could be accounted for.     

Performance of rainbow trout and Snake River cutthroat trout reared in oxygen-supersaturated water

Rainbow trout, Oncorhynchus mykiss, reared in water containing oxygen at 180% or 94% of saturation for 125 days showed no difference in growth or feed conversion. Hematocrits were nominally reduced in fish held in the supersaturated oxygen environment, but increased within 35 days of returning the fish to water at 94% oxygen saturation. Mortality was not affected. Hemoglobin levels did not differ statistically between treatments by the end of the trial. Cutthroat trout, O. clarki, reared in 183%, 127% or 97% oxygen-supersaturated water for 91 days also showed no differences in growth or feed conversion. Hematocrits decreased nominally as dissolved oxygen was increased. There were no differences in mortality during handling or distribution stress tests. Results of these trials indicated that long-term culture in water saturated up to 183% oxygen has no adverse effect on growth or survival of these two species.     

Influence of acclimation temperature on the osmotic regulation and survival of rainbow trout (Salmo gairdneri) rapidly transferred from fresh water to sea water

Certain physiological responses of two groups of rainbow trout acclimated at 10 and 17°C to a sudden change in salinity were investigated in order to determine the most appropriate temperature for direct transfer in salt water. Plasma osmolarities of fish acclimated at 17°C increased at a much faster rate following transfer and approached a much higher value than that reached by the fish acclimated at 10°C. The same was apparent for body tissue dehydration. Haematocrit values, the number of red blood cells, as well as red cell volume showed no significant difference between the two groups of fish for most of the experimental period. The larger increases in plasma osmotic pressure and tissue dehydration observed at 17°C are discussed in connection with the physiological adjustments accompanying higher temperature acclimation.     

地下井水集约化养殖金鳟试验

金鳟作为一种新兴的名贵养殖品种,逐步受到人们的关注,本试验采取利用地下井水,室内工厂化高密度养殖的方式进行养殖,经过近8个月的时间,在480 m2的养殖池塘中,共生产成鱼16 t,平均规格达到357.4 g/尾,成活率为90%,获取了良好的经济效益,为金鳟的高密度养殖探讨了一条新路。     

Demand-feeding behaviour of rainbow trout

Rainbow trout learned quickly to operate a trigger to deliver dry food and showed a peak of feeding at dusk, but also appreciable nocturnal feeding. Food deliveries were aggregated into feeding bouts with a preferred time between trigger presses of 4–8 min; the aggregation of feeds was more marked in groups of trout than with trout held singly. Total daily food intake varied with the reward level per trigger press, and could therefore be controlled at about the manufacturers recommended feeding levels. Territorial and hierarchical behaviour were observed and in groups of up to 20 trout only one member of the group pressed the trigger although all the fish took the food delivered, and there was no evidence that smaller fish in a group were deprived of food to the point at which they lost condition.     

虹鳟养殖技术之一利用水库底层水养殖虹鳟

虹鳟鱼属冷水性鱼类,生长快,抗病力强,是目前深受养殖户和消费者喜爱的品种之一.2002年,我们利用凌源菩萨庙水库底层水进行虹鳟商品鱼养殖试验,取得较好的经济效益.     

Vaccination of rainbow trout, Oncorhynchus mykiss (Walbaum), against cryptobiosis: efficacy of the vaccine in fresh and sea water

Adult rainbow trout, Oncorhynchus mykiss (Walbaum), maintained in either fresh or sea water were vaccinated with a live Cryptobia salmositica vaccine. All vaccinated fish were protected 4 weeks later against the cryptobiosis, while unvaccinated rainbow trout developed the disease (e.g. high parasitaemia and severe anaemia) after challenge with virulent C. salmositica . There was also no disease in vaccinated fish when they were transferred from fresh to sea water immediately after vaccination. Complement fixing antibodies (CFAbs) were detected in vaccinated fish and the CFAbs lysed parasites under in vitro conditions. The antibody titres increased rapidly at one week post-challenge in vaccinated fish in fresh water and vaccinated fish transferred from fresh water to sea water after vaccination. However, the production of CFAbs was delayed by one week in vaccinated fish in sea water and the antibody titre was significantly lower than that in fish maintained in fresh water.     

集约化流水养殖虹鳟鱼实用技术

2001年开始在辽宁省建昌县药王庙乡进行虹鳟鱼的养殖,经过几年的发展,已有养殖水面2 670m2,收到较高的经济效益和较好的社会效益.现将集约化流水养殖虹鳟鱼的技术介绍如下. 1场地选择     

提高虹鳟、金鳟鱼苗成活率的关键技术

在虹鳟及金鳟鱼苗的养殖中,鱼苗的成活率是养鳟鱼场取得良好经济效益的关键,也是衡量鱼场技术水平的一个重要指标。根据多年的生产实践经验,总结出以下几点,供广大鳟鱼养殖户参考。     

Primary responses of rainbow trout to dietary phosphorus concentrations

A series of experiments was conducted to research sensitive indicators for phosphorus status of fish using post‐juvenile rainbow trout. Fish were fed up to 24 days with semipurified diets that varied in phosphorus content. Concentrations of glucose‐6‐phosphate, ATP, creatine phosphate, glucose, total lipids and total cholesterol in blood or skeletal muscle were relatively unchanged by the 24 days of dietary phosphorus restriction. Inorganic phosphorus and ATP levels in the blood, however, correlated significantly and positively. Inorganic phosphorus levels in plasma and urine were significantly lower in fish fed phosphorus‐deficient diets than phosphorus‐supplemented diets. Urinary phosphorus excretion peaked 6–10 h after feeding fish with diets containing potassium phosphate. Fish receiving either commercial feeds or experimental diets containing phosphorus as fish bone excreted trace amounts of phosphorus in the urine. Faecal content of phosphorus significantly increased when the diet containing potassium phosphate was supplemented with calcium carbonate. Urinary phosphorus concentration was found to be a rapid and sensitive indicator for dietary intake of phosphorus and probably phosphorus status of the fish, and had an advantage over conventional response variables in estimating dietary phosphorus requirement especially with large commercial‐size fish.     

虹鳟养殖技术 之三武陵山区养殖虹鳟应注意的技术环节

虹鳟是典型的冷水性鱼类,2005年北京市对口支援湖北省巴东县虹鳟鱼养殖项目,当年5月引进鱼苗1.5万尾后放入引水水渠中饲养,之后在水渠下方建新鱼池,并将鱼苗转入新池     

(革丽)靬金鳟和虹鳟生长对比试验

革丽革干金鳟是红鳟的一个变异种 ,由甘肃省永昌金鳟鱼培育繁殖中心于上世纪末培育成功 ,具有良好稳定的遗传性。经 2 0 0 0年 11月 2 2日农业部专家组鉴定 ,取名为“永昌金鳟一号”。与日本金鳟相比 ,其体色更加金黄艳丽 ,眼球血红 ,集食用和观赏价值于一体 ,目前市场售价是虹鳟的 2～ 3倍。作者就其生长性能与虹鳟作了对比试验 ,以期为我省推广养殖该鱼提供参考。1　试验材料1 1　鱼池　试验用鱼池为榆中县虹鳟鱼试验场7#、 8#鱼苗池 ,两池并联 ,为长方形水泥池 ,大小相同 ,长 6m ,宽 1 5m ,深 0 5m ,面积 9m2 。鱼池进水口与最高水位有 …     

Production of all-female triploid rainbow trout

Triploid rainbow trout were produced by heat shock treatment of eggs soon after fertilization with either normal sperm or sperm from masculinised females. The proportion of triploid fry, as judged from red blood cell nuclear volume, varied between 75% and 100% in three experiments using different batches of eggs from an autumn-spawning strain of trout while a single batch of eggs from a winter-spawning strain yielded 50% triploids.

A microscopic examination of the gonads was made on 5-month-old fish weighing between 1 and 3 g. In female controls the ovaries were packed with oocytes while those from female triploids, although showing the typical lamellar structure of an ovary, contained no oocytes, thus indicating that female triploids are sterile. The testes from triploid males appeared to be developing normally.

The use of masculinized females combined with heat shock treatment of eggs to produce triploids, allowed the production of sterile all-female triploids. This should have considerable potential for aquaculture.     

淡水人工培育中华鲟亚成体的海水驯化试验

2000年,采用阶段性递增水体盐度,即每5d将水体的盐度逐渐提高5,并不设稳定期的方法,对在淡水环境人工养殖近3年的中华鲟子一代亚成体(全长105～149cm,体重5.8～15.0kg)进行海水驯化试验。结果表明,经过20d的驯化,较大规格的中华鲟亚成体即可适应盐度为23的海水环境,驯化的成活率平均达到93.9%(92.1%～95.7%)。水体盐度增加时没有发现中华鲟有异常的行为表现,而驯化后的中华鲟在海水池塘中也能够正常生长。研究还表明,中华鲟对其栖息水体的盐度有较强的适应能力,但其耐盐性和适应能力可能与个体规格大小有一定的关系,即个体的规格越大,则其对水体盐度变化的适应能力就越强。     

虹鳟养殖技术 之二虹鳟海水网箱养殖技术探讨

近年来,北方沿海地区开始发展深水网箱养鱼,但由于适宜的养殖品种较少以及缺乏适宜产业化运做模式等问题,发展受到制约。2007年,笔者以打造定单式"公司 养殖户"模     

地下溶洞水养殖虹鳟试验总结

福建省宁化县地下溶洞水资源丰富,主要为碳酸盐岩类裂隙溶洞水,分布于泉上、湖村、安乐等三个乡镇,面积126.4km2,每年地下径流量达19,378,100t,全县有较大的出水口9处,水温16℃~21℃,流量0.1m3/s~1.2m3/s,水质清新而无任何污染,但至今多数还处于闲置状态。为开发利用这一资源优     

Comparison of growth rate in Atlantic salmon,pink salmon,Arctic char,sea trout and rainbow trout under Norwegian farming conditions

Growth rates of Atlantic salmon, pink salmon, Arctic char, sea trout and rainbow trout were compared under Norwegian farming conditions. During the juvenile, freshwater period, growth was fastest in pink salmon, followed by rainbow trout and Arctic char. Freshwater growth of sea trout and, especially, Atlantic salmon, was slow. After transfer of smolts or fingerling to sea water, Arctic char failed to survive the autumn. Sea water growth of sea trout was slow, but the three species, rainbow trout, Atlantic salmon and pink salmon, all grew rapidly through all seasons. When in sea water, rainbow trout and pink salmon were regularly attacked by vibriosis, while Atlantic salmon were rarely attacked, and sea trout never. It is concluded that, for commercial farming in Norway, rainbow trout are of value for production of fish of any size up to 3–4 kg, and pink salmon for production of small fish of 0.5–1.5 kg. Atlantic salmon is the only species suitable for production of a very large salmonid, i.e., more than 4–5 kg.     

Insulin binding to isolated hepatocytes of Atlantic salmon and rainbow trout

The questions addressed in this study were: 1) whether insulin added to the incubation medium can down-regulate ¹²⁵I insulin binding to isolated hepatocytes of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss); 2) whether quantitative assessment of insulin processing can be made on isolated fish liver cells; 3) how ambient temperatures can affect insulin binding, and down-regulation of insulin receptors. After isolation and a short (up to 4h) “metabolic recovery period”, liver cells were used either directly in ¹²⁵I insulin binding assay or first preincubated for 18h at 4°C or for 3h at 15°C, with or without mammalian or salmon insulin in concentrations ranging from 1 to 1000 nM. Preincubation at 15°C, decreased binding capacity (number of binding sites per liver cell) in all five independent hepatocyte preparations treated with 1000 nM insulin and in four out of five preparations treated with 100 nM insulin. At 4°C insulin binding sites were down-regulated in less than 50% of all hepatocyte preparations and only in the presence of 1000 nM insulin. Differential quantitive assessment was made of a) intact free insulin; b) insulin degraded; c) intact insulin bound to the cell membrane; d) internalized but degraded insulin, and e) intact insulin internalized by liver cells. Hepatocytes preincubated with 100 – 1000 nM insulin at 15°C bound and internalized less ¹²⁵I insulin. We hypothesize that in vivo, at water temperatures of 15°C and higher, extreme physiological levels of plasma insulin may regulate the numbers of insulin receptors in the salmonid liver. In contrast, in fish inhabiting cold waters the regulation of insulin receptors by circulating plasma insulin seems to be of little physiological importance. Presented in part at the Western Regional Conference on Comparative Endrocrinology, Tempe, Arizona, U.S.A., 1991 and at the Meeting of Italian Society of Experimental Biology, Sorrento, Italy, 1991. Supported by grants from NSF of the USA#DCB 8915935 to E.M.P., NSERC of Canada OPGA 6944 to T.W.M., North Atlantic Treaty Organization (NATO) grant #0926/87 to C.O. and E.M.P., and CYCIT grant of Spain to J.G.