漠斑牙鲆幼鱼和成鱼对盐度的耐受力试验

盐度是影响漠斑牙鲆生长发育和繁殖的重要因素之一。试验证实,漠斑牙鲆在盐度0～60的环境中能够生存,生长的最佳盐度为5～35,对盐度的适应性广,这一点很有利于该鱼种在我国南、北方的海域和内陆广大地区进行大范围推广。莱州市大华水产有限公司、莱州市海洋水产研究所在“漠斑牙鲆规模化养殖技术研究”项目中,进行了漠斑牙鲆幼鱼和成鱼对盐度的耐受力试验。     

盐度对漠斑牙鲆幼鱼生长与存活的影响

本文就盐度对漠斑牙鲆幼鱼的生长及存活的影响进行了探讨,结果表明:漠斑牙鲆幼鱼适宜盐度范围为0～36,最适盐度范围为6～18。在适宜盐度下,漠斑牙鲆幼鱼生长快,存活率高。过高或过低的盐度对幼鱼的生长发育均有一定的抑制作用。     

漠斑牙鲆淡水养殖试验

漠斑牙鲆(Paralichthys lethosigma),又称南方鲆,隶属于鲽形目、鲽亚目、鲆科、牙鲆亚科,牙鲆属,原产于美国北卡莱罗纳州至佛罗里达州南部海湾。该鱼具有生长快、品质优、适应范围广、抗病、抗逆性强、肉质细腻、营养丰富等特点,在海、淡水中均能生长,是我国内陆和沿海地区不可     

盐度对漠斑牙鲆幼鱼存活、生长及摄食的影响

盐度对漠斑牙鲆幼鱼的存活的影响较小,将漠斑牙鲆幼鱼从盐度为32的海水直接放入盐度为24、16、8、0的水中观察48 h存活情况,仅盐度0组成活率为75%,其他盐度组均为100%.在盐度为32、24、16、8、0各试验组中,经1个月饲养,生长速度和饵料系数均无显著差异.盐度越低越有利于漠斑牙鲆白化个体康复正常体色.     

淡水池塘网箱养殖漠斑牙鲆试验报告

通过对漠斑牙鲆淡水池塘网箱养殖试验,掌握了该品种的生活习性,探索出漠斑牙鲆内陆地区淡水养殖模式,总结出养殖过程中应采取的技术措施。25m~2网箱总产漠斑牙鲆102．9 kg,平均单产4．12 kg/m~2,平均规格为306．25 g/尾,成活率达84%。     

漠斑牙鲆低盐度室内——苗种培育试验

漠斑牙鲆,又名南方鲆(Paralichthyslehostigma),隶属鲽形目,鲆科,牙鲆属。其肉质鲜美,并具有食性杂、适盐范围广等特点,经变态后的幼鱼可直接在淡水中养殖,喜聚群、生长快,在适宜条件下当年可达500克左右。漠斑牙鲆最佳适盐范围5~30,最佳水温适应范围18~30℃,pH最佳为7郾0~8郾2     

温度对漠斑牙鲆幼鱼生长与存活的影响

本文根据温度实验,对漠斑牙鲆幼鱼的生长及存活的影响进行了探讨。结果表明：漠斑牙鲆幼鱼适宜生长温度范围为15—30℃,最适温度范围为18～27℃。在适宜温度下,漠斑牙鲆幼鱼生长快,存活率高。过高或过低的温度对幼鱼的生长发育均有一定的抑制作用。在生产上,当培育水体温度低于15℃时应进行人为加温,对促进幼鱼的生长发育与存活有积极意义。     

漠斑牙鲆幼鱼和成鱼对温度的适应性试验

温度对鱼类养殖非常重要,它不仅影响鱼类的繁殖和发育,也影响生长速度。漠斑牙鲆属水生变温动物,它的体温随生活水域的温度变化而变化,而水温变化会直接影响鱼的代谢水平,从而影响摄食和生长,温度过高或过低都会使鱼死亡。一般在适温范围内,鱼的摄食量增加,生长加速;而当水温过高或过低时,会出现摄食量减少、行动迟缓、生长变慢的现象。     

漠斑牙鲆仔鱼摄食节律的研究

在实验室条件下研究了漠斑牙鲆仔鱼摄食节律。试验结果表明：漠斑牙鲆仔鱼摄食具有昼夜节律性,其摄食活动主要在白天进行,在10：00光照度为400lx时摄食最为活跃,抵达摄食高峰,仔鱼夜间不摄食,全天表现明显的摄食节律。     

漠斑牙鲆室内淡水养殖技术

漠斑牙鲆(Varalichthys lethostigme)隶属鲽形目，鲆科．牙鲆属。该鱼杂食性，适盐范围广，变态后的幼鱼可直接在淡水中养殖，喜聚群，生长快，在适宜条件下当年可达500g左右，且具有抗病力强，较耐高温，对环境的适应能力强，耐低氧，易运输等特点。在国外如美国、日本、韩国等倍受消费者青睐，具有较高的经济价值和营养价值，养殖前景十分广阔。     

Growth and performance of the whiteleg shrimp Penaeus vannamei (Boone) cultured in low‐salinity water with different stocking densities and acclimation times

We evaluated the performance of whiteleg shrimp Penaeus vannamei (Boone, 1931) in response to different stocking densities and acclimation periods. Shrimp postlarvae were acclimated from seawater (30 g L^?1) to low‐salinity well water (<1.0 g L^?1) at a constant hourly reduction rate of 40, 60, 80 and 100 h. After acclimation to low‐salinity well water, postlarvae from each acclimation time treatment were stocked in three replicate tanks at densities of 50, 100, 150 or 200 shrimps m^?2 for 12 weeks of growth. Salinity averaged <1.0 g L^?1 for each growth study. The different treatments resulted in significant differences in both the final body weight and the survival rate (SR). Shrimp acclimated for 100 h showed substantially improved survival (83%) relative to shrimp acclimated for shorter periods. Shrimp yields for all cultured periods ranged from 0.32 kg m^?2 in tanks stocked at 50 m^?2 to 1.14 kg m^?2 in tanks stocked at 200 m^?2. We conclude that whiteleg shrimp can be successfully grown in low‐salinity well water, and that the growth, production output and SRs are significantly higher when shrimp are acclimated for longer periods.     

低盐度对泥东风螺(Babylonia lutosa)稚螺生长与存活的影响

采用盐度渐变和突变2种方法试验低盐度对平均体重3.7 mg、平均壳高(2.24±0.24)mm的泥东风螺稚螺生长与存活的影响。结果表明:盐度28时,稚螺的生长速度最快,盐度降到24时,对稚螺的影响并不明显,摄食基本正常,但活力略有降低;变态7 d的泥东风螺稚螺能够适应高于21的低盐环境,存活基本正常,有比较高的成活率,但对其摄食和生长有一定的影响;当盐度突变至18时,泥东风螺稚螺仍能存活,突变至15时,则不能存活;而盐度渐变至15时,稚螺仍可存活;盐度逐渐降低只可扩大泥东风螺稚螺的存活盐度范围,但其对最适生长盐度范围影响有限。     

嘉庚蛸对温度、盐度的耐受性试验

2003年4～10月在试验条件下研究了嘉庚蛸成体对温度、盐度等环境因子的耐受能力。利用温水和冰水调节水温，在温控加热器和生物冰袋的协助下完成温度耐受性试验；通过淡水和海水晶调节试验过程中所需的盐度变化。试验结果表明：嘉庚蛸的适宜温度范围为12．0℃～31．0℃，临界上限水温为35．2℃，临界下限水温为0．5℃；耐受盐度的范围比较广泛，为4．8～48．5，适宜养殖的盐度为18．4～33．1。较高的耐受性范围可以保证嘉庚蛸更好地适应其生存的环境，不至于由于环境因子的激变造成嘉庚蛸的大规模死亡。因此，人工养殖和育苗过程中，保持环境因子的稳定是获得高孵化率的先决条件。     

三种鳅科鱼对NaCl盐度和NaHCO3碱度的耐受能力

以鳅科的黑龙江泥鳅(Misgurnus mohoity Dybowsky)、大鳞副泥鳅(Paramisgurnus dabryanus Sauvage)、达里湖高原鳅(Triplophysa dalaica)为实验材料,采用单因子静态急性毒性实验法和均匀正交设计法对其盐碱耐受能力进行研究。实验结果表明,黑龙江泥鳅、大鳞副泥鳅、达里湖高原鳅的24 h和96 h的氯化钠(Na Cl)盐度半致死浓度(LC50)分别为15.64 g/L和13.58 g/L、15.43 g/L和14.18 g/L、14.00 g/L和11.57 g/L,安全浓度(SC)分别为4.12 g/L、4.03 g/L、3.74 g/L,盐度耐受能力顺序为:黑龙江泥鳅大鳞副泥鳅达里湖高原鳅。黑龙江泥鳅、大鳞副泥鳅、达里湖高原鳅的24 h和96 h碳酸氢钠(NaHCO_3)碱度半致死浓度(LC50)分别为117.1 mmol/L和72.62 mmol/L、128.4 mmol/L和88.83 mmol/L、155.2 mmol/L和120.0 mmol/L,安全浓度分别为18.77 mmol/L、23.66 mmol/L、36.30 mmol/L,碱度耐受能力顺序为:达里湖高原鳅大鳞副泥鳅黑龙江泥鳅。盐碱交互作用对黑龙江泥鳅、大鳞副泥鳅均表现为协同作用,协同系数0~48 h依次增高,以后逐渐减小;而对达里湖高原鳅在0~48 h内表现为协同作用,在48~96 h时表现为拮抗作用,拮抗系数随着暴露时间的延长而增大。对比分析可知,3种鳅科鱼的盐碱耐受能力比大多数淡水鱼高,可作为盐碱水域的增养殖鱼类;而达里湖高原鳅在耐碱方面表现更突出,可以作为高碳酸盐型盐碱水的增养殖鱼类。     

Larval development and salinity tolerance of Japanese flounder (Paralichthys olivaceus) from hatching to juvenile settlement

Salinity tolerance and growth of Japanese flounder Paralichthys olivaceus at different developmental stages were evaluated, including newly hatched larvae (nhl), yolk sac larvae (ysl), oil droplet larvae (odl), post oil droplet larvae (podl), premetamorphic larvae (preml) and prometamorphic larvae (proml), at 11 salinities from 5 to 55 g L^?1 for 96 h. The ontogenesis during the early life of P. olivaceus was investigated under hatchery salinity 35 g L^?1. The results showed that suitable salinities for nhl, ysl, odl, podl, preml and proml larvae were 10 to 25 g L^?1, 10 to 30 g L^?1, 20 to 30 g L^?1, 30 g L^?1, 10 to 30 g L^?1, 15 g L^?1, respectively, demonstrating an ontogenetic variation of salinity tolerance. The salinity tolerance of nhl, ysl, preml was higher than that of odl, podl and proml. The ysl and preml larvae displayed wide salinity tolerances. The present findings demonstrate that the suitable salinity for larviculture of P. olivaceus is 20–25 g L^?1 before the depletion of oil droplet; after that, higher salinity (30 g L^?1) should be ensured for the post‐oil droplet larvae; the premetamorphic larvae can be cultured at a wide salinity range (10–30 g L^?1), and the metamorphosed larvae should be reared at salinity about 15 g L^?1.     

盐碱地低盐水池塘网箱套养漠斑牙鲆技术研究

根据漠斑牙鲆(Paralichthys lethostigma)适广温、广盐和较强的抗逆性等优良生态习性,采用地下卤水、盐碱地渗水,通过合理淡水配兑使其适合漠斑牙鲆生理生长需求,在我国中纬度地区利用盐碱地低盐水养殖过洋、暖温性漠斑牙鲆。2004-2005年,利用盐碱地低盐水池塘虾池设置网箱套养漠斑牙鲆349.5m2,产鱼3.749t,产虾55.065t,其中2005年虾池设置网箱套养漠斑牙鲆306m2,产鱼3.245t,平均10.6kg/m2,平均全长34.0cm,体重527.4g,养殖成活率为90.5%,产虾49.003t,平均408.4kg/亩,平均规格11.9cm,养殖成活率为71.23%。虾池设置网箱套养漠斑牙鲆,可充分利用水体空间,促使池塘高产高效,提高养殖经济效益。     

Digestibility of feed ingredients in Florida pompano,Trachinotus carolinus adapted to either sea water or low salinity

Seven potential feed ingredients were evaluated for digestibility with Florida pompano Trachinotus carolinus using extruded diets. Ingredients included Special Select^? menhaden meal, fishery processing by‐product (Montlake meal), NuPro^® yeast extract, canola protein concentrate, corn protein concentrate, barley protein concentrate and Spirulina. Digestibility values were determined when fish were held at 3 and 28 g L^?1 salinity to determine the effect of salinity on digestibility. With the exception of the canola protein concentrate, the coefficients were numerically higher in pompano held at 28 g L^?1. No significant differences were detected for apparent crude protein or apparent energy digestibility between the two salinities. Amino acids were highly available from the two marine‐based ingredients and the barley and canola concentrates. The availability of alanine, leucine, isoleucine and phenylalanine was significantly higher (P < 0.05) from the barley protein concentrate at 28 g L^?1 than 3 g L^?1 salinity. Methionine and phenylalanine were highly available from all the ingredients except the yeast protein. Conversely, glycine was not well utilised from any of the ingredients. The apparent digestibility coefficients provided here allow for more precise formulation of diets for Florida pompano reared in both seawater and low‐salinity environments.     

The quality of release habitat for reared juvenile flounder, Platichthys flesus, with respect to salinity and depth

Abstract  One prerequisite for a successful stocking programme is the choice of an appropriate release site, which would ensure good growth, survival and recruitment to the local fishery. The influence of different salinity regimes on habitat quality for juvenile flounder, Platichthys flesus (L.), was examined in Danish inshore waters using enclosures to study growth and survival. Three locations were chosen: Virksund (V) – constant low salinity at 10‰; Harre Vig (HV) – constant high salinity at 24‰; and Hjerk Nor – variable salinity, 0–25‰. Fish movement was examined, using a diffusion model, at the first two sites. At HV the fish had unrestricted dispersal opportunity resulting in average individual movement of 45 m day⁻¹. Fish at V were restricted in dispersal in one direction because of a dam, about which they would concentrate under certain hydrographical conditions. Growth was highest at the locations with stable salinity and mortality highest at the location with variable salinity.     

Dietary magnesium requirement and physiological responses of marine shrimp Litopenaeus vannamei reared in low salinity water

An 8‐week feeding experiment was conducted to determine the dietary magnesium (Mg) requirement and physiological responses of Litopenaeus vannamei in low salinity water of 2 g L^?1. Casein–gelatin‐based diets supplemented with seven levels of Mg (0, 0.4, 0.8, 1.6, 3.2, 6.4 and 8.0 g kg^?1) were fed to juvenile shrimp. Prior to the experiment, the postlarvae were gradually acclimated to the low salinity media and fed with a basal diet (0.5 g Mg kg^?1) for 2 weeks. After 8 weeks of feeding, survival ranged from 80.11% to 85.65% with no significant difference among the treatments. Hepatopancreas Mg²⁺‐ATPase and Na⁺/K⁺‐ATPase activities and muscle content of lipid and protein were not significantly affected by graded levels of Mg. The weight gain and mineral (calcium, potassium, sodium and total phosphorus) content of different tissues were significantly affected by dietary Mg levels, while there were no significant differences in ash and zinc content in tissues. The Mg content in tissues except hepatopancreas was maintained relatively constant regardless of dietary treatments. The dietary Mg requirement for optimal growth was 2.60–3.46 g Mg kg^?1 by using the polynomial regression analysis based on growth.