Feeding,growth and environmental requirements of Arctic charr: a review of aquaculture potential     

Malcolm Jobling  Even H. Jørgensen  Arne M. Arnesen  Einar Ringø 《Aquaculture International》1993,1(1):20-46

Interest in the cultivation of Arctic charr arose during the 1970s, and research into charr farming was instigated in the Nordic countries and in Canada. Most work has been conducted on fish from anadromous populations, although land-locked freshwater populations of Arctic charr have also received attention. Research has also been carried out in the British Isles and in the alpine regions of central Europe, where land-locked populations of charr. Small-scale commercial farming is now carried out in several countries of northern Europe and North America, and charr are reared for restocking purposes in a number of countries.Growth of charr is rapid during the early freshwater rearing stages, and quite good rates of growth can be achieved at low water temperatures. Growth may be submaximal if charr are reared in systems designed for other salmonids, and problems may arise when charr are held at low stocking densities. Growth and food conversion can be improved by exposing the fish to water currents, forcing them to swim at moderate speeds. Growth in seawater has been reported as being highly variable, probably as a result of the use of inappropriate rearing techniques and owing to the seasonal changes in the hypo-osmoregulatory ability of the charr.Prospects for aquaculture development and areas requiring further research effort are briefly discussed.  相似文献   

Response of a Juvenile Cyprinid,Lake Minnow <Emphasis Type="Italic">Eupallasella perenurus</Emphasis> (Pallas), to Different Diets     

Rafa??KamińskiEmail author  Micha??Korwin-Kossakowski  Jan?Kusznierz  Leszek?Myszkowski  L. Andrzej?Stanny  Jacek?Wolnicki 《Aquaculture International》2005,13(5):479-486

Three commercial starters (Carp Starter, Uni Starter and Perla Plus) and one non-commercial, with frozen Chironomidae larvae as a reference diet, were evaluated for the intensive rearing of juvenile lake minnow Eupallasella perenurus, a cyprinid fish that is critically endangered in Poland. The growth, condition, survival, body deformities, and chemical body composition were studied. The 90-day laboratory experiment was performed at 22 °C with fish that were initially 24.6 mm (mean total lenth (TL)) and 0.11 g (mean body weight (BW)). Satisfactory fish growth was attained with all of the diets; however, the largest (p ≤ 0.05) final size (48.5 mm TL, 1.55 g BW) and the lowest condition coefficient (K = 1.34) were noted in fish fed the non-commercial starter. The final survival rates were very high (97.5–100%). Skeletal deformities (in 74 to 92% fish) were recorded exclusively in fish fed commercial starters. All commercial starters resulted in considerably higher lipid content and lower ash content than did the non-commercial starter and the reference diet. This suggests that both these factors might be responsible for body deformities. The present results proved that only the non-commercial starter is suitable for juvenile E. perenurus rearing under controlled condition, and that none of the commercial starters can be recommended.  相似文献   

Prey extracts evoke swimming behavior in juvenile Atlantic halibut (Hippoglossus hippoglossus)     

S.Y. Yacoob  H.I. Browman 《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):570-573

This study tested the efficacy of prey extracts to induce food search behavior in juvenile (15–25 cm total length, 0 year group) Atlantic halibut (Hippoglossus hippoglossus). In square culture tanks, halibut responded to shrimp and squid extract by tightly turning towards the source of the stimulus and by swimming in circles for 2–5 min following stimulus delivery. Cod extract, or a synthetic mixture consisting of glycine, proline, betaine, arginine, and alanine, failed to evoke this behavior.  相似文献   

Feeding has the largest effect on the ammonia excretion rate of the southern rock lobster, Jasus edwardsii, and the western rock lobster, Panulirus cygnus     

B. J. Crear  G. N. R. Forteath 《Aquacultural Engineering》2002,26(4):239-250

The total ammonia nitrogen (TAN) excretion of spiny lobsters Jasus edwardsii and Panulirus cygnus, was determined in relation to temperature, body weight, emersion, daily rhythm and feeding. Temperature and body weight had large influences on the rate of TAN excretion. Exponential relationships were found between temperature (T) and TAN excretion of both species. These were described by the following equations: J. edwardsii Log₁₀ TAN=0.041T−3.57 (r²=0.979, F=143.2, P=0.001), P. cygnus Log₁₀ TAN=0.057T−3.90 (r²=0.987, F=302.2, P<0.001). TAN excretions of both species were positively correlated to body weight (W), and the relationships were described by the following equations: J. edwardsii Log₁₀ TAN=0.473 log₁₀ W−1.704 (r²=0.42, F=14.05, P=0.001), P. cygnus Log₁₀ TAN=0.499 log₁₀ W−1.346 (r²=0.69, F=44.18, P<0.001). TAN excretion increased significantly when lobsters were re-immersed after a 30 min period of emersion. However, it returned to pre-emersion levels by the second hour of re-immersion. Daily rhythm resulted in a significantly higher nocturnal TAN excretion rate for J. edwardsii; no daily rhythm was observed for P. cygnus. Feeding had the largest influence on TAN excretion, with maximum increases of 6.28 (J. edwardsii) and 5.60 (P. cygnus) times the pre-feeding level. TAN excretion rates remained significantly higher than the pre-feeding levels for an extended period (26 h, J. edwardsii; 30 h, P. cygnus). Implications for the use of purging tanks in lobster holding facilities and for the design of biofiltration systems are discussed.  相似文献   

摄食促进剂对对虾生长的影响   总被引：5，自引：0，他引：5  

梁萌青  常青等 《海洋水产研究》2001,22(4):71-74

IntroductionMeasures to assure that all feed offered to animals in commercial operation is consumed and to reduceformulated feed waste pollution,have been considered as some of the most relevant for lowering productioncosts in aquaculture.Considering the importance of chemical stimulant in development of the crustacean lifecircle,it is logical to assume that by adding attractants to the feed,the animal would rapidly find potentialfeed and ingest it.Additionally,measures involving the incorpora…  相似文献   

Study on the Acute Toxicity of Rare Earth Yttrium to Earthworms under the Stress of Leaching Agent Ammonium Sulfate     

冯秀娟  马彩云  孙峰  鄱洋  朱易春  高咪  阎思诺 《农业科学与技术》2014,(2):177-181,190

[目的]考察浸矿剂硫酸铵（NH4）2SO4胁迫下稀土离子钇的毒性研究。[方法]选择蚯蚓作为土壤生态环境污染指示生物,采用滤纸接触法研究硫酸铵胁迫下稀土钇（ Y）对蚯蚓的急性毒性效应。[结果]①稀土钇单一染毒,蚯蚓的48 h 半致死率浓度为 LC50=213.41 mg/L、24 h半致死率浓度为 LC50=322.63 mg/L。②硫酸铵单一染毒下,蚯蚓的48 h半致死率浓度为 LC50=13.89 g/L、24 h半致死率浓度为LC50=15.05 g/L。③低浓度10 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度LC50=198.65 g/L、24 h 半致死率浓度 LC50=399.85 g/L;中浓度14 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度 LC50=167.3 mg/L、24 h半致死率浓度 LC50=256.73 mg/L;高浓度20 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度 LC50=31.03 mg/L、24 h的LC50=127.65 mg/L。[结论]低浓度的硫酸铵降低稀土钇对蚯蚓的毒性,产生一定的拮抗作用。中浓度的硫酸铵增加稀土钇对蚯蚓的毒性,产生较明显的协同作用。高浓度硫酸铵显著增加了稀土钇对蚯蚓的毒性。稀土钇染毒下蚯蚓死体更易断裂,而活体对针刺反应相对不灵敏。  相似文献   

改良剂组合对盐碱土的改良效果研究     

单德鑫  黄河  柳羽丰  李海统  李晓秀  卢丽英 《安徽农业科学》2014,(35):12491-12493

[目的]从所选取的5种物质（石膏、粉煤灰、油脂素、沸石粒、钾粒）中筛选对盐碱土改良效果最好的改良剂及其最佳组合方式.[方法]采取单一施用、两两施用,3种混施的方式将改良剂与土壤混合,通过盆栽试验对土壤进行一段时间的培养,检测各指标的变化.[结果]5种土壤改良剂及其组合对盐碱土的pH、部分肥力指标及水溶性离子含量均有一定程度的改良.对全磷和有效钾改良效果最好的是粉煤灰和油脂素组合施用;对pH、水溶性离子及其他肥力指标改良效果最好的是石膏、粉煤灰和油脂素3种改良物质混合施用.[结论]改良剂混合施用比单一施用效果好.  相似文献   

Early development of the shortfin silverside Chirostoma humboldtianum (Valenciennes, 1835) (Atheriniformes: Atherinopsidae)     

Ma. Cecilia Hernández-Rubio  Gerardo Figueroa-Lucero  José Luis Arredondo-Figueroa 《Aquaculture (Amsterdam, Netherlands)》2006,261(4):1440-1446

The shortfin silverside Chirostoma humboldtianum has been considered for culture in Mexico, but success has been limited by a poor knowledge of its early development. First synthesis of the early development of the shortfin silverside is presented to determine conditions suitable for rearing. Brooder maturation was induced through photothermal cycles. C. humboldtianum ova were fertilized in vitro. The eggs were incubated in reconstituted water (160-180 mg/L CaCO₃) at 18 °C and 5 gm of NaCl per litre. During the hatching day, 300 shortfin silversides were stocked and followed up until metamorphosis in order to establish the timing of exogenous feeding, changes in food type, growth and development during critical periods for survival, according to the theory of saltatory ontogeny. Free embryos hatched 12 days after fertilization at 18 °C. First critical point for survival is the beginning of exogenous feeding. Free embryos started mixed feeding on day four of post-hatching (dph), point of no-return was presented towards the end of mixed feeding on 6 dph, larval period began at six (dph) when the anus is opened, and metamorphosis to juvenile was presented at 65 dph with a SL of 19.34 ± 2.28 mm, when scales and fins were well developed. Differences in growth between periods were detected: free embryos growth slower than larvae but mouth size depicted a larger growth rate in the former. Cephalic length and mouth size were negatively related to standard length in embryos and larvae. Mouth size was positively related to cephalic length in free embryos but negative in larvae. Results suggest that during the free embryo phase, growth priorities are directed to the development of apparatuses and systems; whereas, during the larval period, energy is directed to growth in length, mouth size and development of fins, which allows them to increase their swimming velocity, grants them a greater capacity to obtain exogenous food and, in consequence, increases fitness for survival.  相似文献   

魁蚶食性及摄食季节变化的初步研究     

王俊 《海洋水产研究》1994,(15)

根据1990年10月～1991年9月在山东烟台近海采集的魁蚶样品观察和分析,结果表明,魁蚶的食物组成比较简单,以摄食植物性饵料为主,兼食浮游动物。主要种类有硅藻门的圃筛藻、舟形藻、菱形藻、曲舟藻、沟直链藻和粗纹藻以及浮游动物中的挠足类。除冬季外,魁蚶在其他季节均摄食。摄食的种类主要取决于自然海域中硅藻类等优势饵料生物种类的季节变化。  相似文献   

Fish larvae: zooplankton relationships in microcosm simulations of earthen nursery ponds. II. brackish water system     

Ana Milstein  Arie Valdenberg  Sheenan Harpaz 《Aquaculture International》2006,14(5):431-442

A simulation of the effects of predation intensity on zooplankton composition in brackish water nursery ponds was carried out in order to address the problem that commercial fish nurseries encounter in obtaining enough zooplankton of adequate species composition and size when fish larvae start to feed. The experimental system consisted of twelve 130 l containers with treatments of four densities (0, 1, 2, or 4 larvae l⁻¹) of common carp (Cyprinus carpio L.), stocked on the 6th day after filling the containers. Zooplankton-environment relationships were explored using factor analysis. Factor analysis allowed identifying several groups of zooplankters that responded in different ways to fish larvae predation pressure. The first factor represented a general measurement of rotifer abundance, and the second identified the direct effect of size-selective fish predation. Since no rotifers were present in the filling water, all these species were autochthonous populations that hatched from resting forms in the sediment and reproduced. In the absence of fish predation, this led to a steep rotifer increase. Fish predation started when the rotifer concentration was just starting to increase and their direct predation reduced and delayed the rotifer abundance peak. This effect increased with the increase in fish larvae density. Estimations of rotifer consumption by fish larvae in this experiment were higher than similar calculations from data of the literature, which led us to test the hypothesis that factors other than direct predation were affecting rotifer population dynamics. The mechanisms involved in rotifer population regulation are discussed. It was concluded that in commercial nurseries, increased larvae production can be achieved by keeping the larvae density at an intermediate level and stocking fish to match the increasing phase of the rotifer peak. Under reasonable larvae density (up to 2 l⁻¹) it seems that the direct predation effect of fish larvae on rotifer dynamics is minor, compared to fish induced self regulation.  相似文献