盐度对黄鲷胚胎发育及早期仔鱼生长的影响

The effect of salinity on embryo and early larva development of Dentex tumiforns was discussed. Floating forms of egg in different salinities, optimal salinity for embryonic development and early larva growth was studied. The results showed: 1. In immobile condition, all eggs sank at salinity of 32.0, most of egg ssuspended in the middle of water at 34.0, and all eggs floated on the surface when salinity above 36.0. 2. Eggs did not hatch out at salinity of below 10.0 or above 60.0 and the death time of egg gradually moved up with increase or decline of salinity. Eggs hatched out at salinity range of 15.0 and 50.0, including abnormal larva. There was indistinct difference in speed of embryonic development (about 36-40h) within the salinity of 15.0 and 50.0. However the salinity had a great effect on larval survival after hatching and abnormal rate. The relation between hatching rate and salinity variation showed parabola but abnormal rate showed inverted parabola. The hatching rate was 81%-86% and abnormal rate of yolk sac larva was 27%-30% in suitable salinities of 27.0-39.0. The hatching rate was 89%-91% and abnormal rate was 13%-16% in optimal salinities of 33.0-36.0. The oil ball of abnormal larva was located in the central or front position. With increased extent of salinity, spondyle of larva bended and number of larva with arrhythmia increased. 3. The optimal salinities were 30.0-35.0 based on SAI. The test with SAI showed that SAI of early larvae was 41.25-47.53 at salinities of 30.0-35.0, the yolk and oil ball of 7-8 days larva was completely absorbed with a survival rate of 88%.     

盐度对鲻鱼前期仔鱼生长与存活的影响

本文研究了鲻鱼前期仔鱼在不同海水盐度条件下的生长和存活情况。结果表明：鲻鱼前期仔鱼生长与存活的适宜盐度范围为20－32‰，盐度低于20‰，随盐度下降，前期仔鱼存活率降低，生长速度趋慢；反之，盐度高于32‰，随盐度升高，前期仔鱼存活率降低，生长速度趋缓。     

盐度对日本鬼鲉受精卵发育及仔鱼生长的影响

研究了盐度对日本鬼鲉（Inimicus japonicus）受精卵发育及仔鱼生长的影响,并测定了仔鱼不投饵存活系数（SAI）。结果表明：（1）鬼蚰受精卵盐度在19—35均可孵化,最适盐度为27—31。盐度高于31,孵化率随盐度的升高而降低;盐度低于27,孵化率随盐度的下降而降低。（2）试验盐度范围内鬼铀仔鱼SM值为3．49～22．12,仔鱼生长和存活的最适盐度范围为23～27,适宜盐度范围为19—31。     

温度,盐度对白对虾生长的影响

对虾的存活率总是出现温、盐接近于自然的生境．然而、资料与现场观察的结果并不完全一致。以往对白对虾（PenaeusVannamei）的研究大多数为后期幼体．对稚虾和成虾的研究几乎没有。据Zein—Eldin（1965观察,温度7～35℃时．褐对虾（PanaeusAztecus）后期纳体短期内存活率为80～100％。20’C时最高。不论盐度如何。高温时（25和32℃）体长和体重比低温时（11和18’C）增长迅速。斑节对虾（P．monodon）在短时间内可耐受10’C的低温（MOtoh,1981）。39C存活率高达98％．但温度更高时死亡率也高。温度引＊C,盐度30％,蓝对虾（PStyl…     

盐度对褐菖鲉仔鱼活力影响的研究

实验比较了5个盐度梯度(28、22、16、10、4)下褐菖鲉仔鱼在饥饿条件下的存活状况并测定其不投饵存活系数SAI。结果表明,褐菖鲉仔鱼最适的生存盐度范围在16~22之间,盐度过低或者过高均对褐菖鲉仔鱼的生存不利。     

盐度对卵形鲳鲹胚胎发育和早期仔鱼的影响

观察比较了10种不同盐度（5．0～50．0）条件下卵形鲳鲹（Trachinotus ovatus）受精卵的沉浮性、孵化率和畸形率,以及8种不同盐度（10．0—45．0）下仔鱼存活情况及不投饵存活系数（survival activityindex,SAI）。结果表踢,受精卵在不同盐度下表现出不同的沉浮性,在盐度为25．0以下的海水中呈沉性;在盐度30．0时为半沉浮性;在盐度为35．0的海水中呈浮性。盐度低于10．0或高于50．0,胚胎均不发育;在盐度15．0—45．0范围内,卵形鲳鲹胚胎能完成发育过程孵出仔鱼,但盐度对早期仔鱼的成活和畸形率的影响比较大。统计分析了总孵化率与盐度、畸形率与盐度的相关关系,求得胚胎孵化的预测适盐范围为14．9—39．4,最适盐度为26．0～28．2。在盐度25．0—30．0和无投饵状态下,仔鱼的SAI值为44．19～47．44。     

温度和盐度对花鲈胚胎及前期仔鱼发育影响的初步报告

花鲈（Ｌａｔｅｏｌａｂｒａｘ ｊａｐｏｎｉｃｕｓ）胚胎发育的适宜温度为１０～２２℃，１０℃组中的畸形率偏高，因此最适宜温度为１３～２２℃。短时期的７℃低温对胚胎发育没有影响；前期仔鱼的适温范围与胚胎的适温范围基本一致。胚胎发育的适宜 盐度为１９‰～２８‰，以２２‰～２５‰为最佳；仔鱼对盐度的要求与胚胎期近似。以低盐度和高盐 度相比较，４日龄以后，低盐度似有利于仔鱼存活。     

盐度对南美白对虾生长性能的影响

在八种不同盐度条件下进行南美白对虾的养殖试验,比较其生长性能,结果表明:盐度显著地影响南美白对虾的生长(F>F0.05=3.50),其中南美白对虾在盐度为18的养殖水体中生长速度最快、存活率高、投饵系数较低;方差分析表明南美白对虾的最适生长盐度范围为14～22(｜Xi-Xj｜>LSD0.05)。     

盐度对南美白对虾生长性能的影响

在盐度为 2～ 30范围内设置八个浓度组饲养南美白对虾 ,比较其生长性能。试验结果表明 ,不同盐度显著地影响南美白对虾的生长 (F >F0 .0 5=3.5 0 ) ,其中以盐度为 18的水体 ,虾的生长速度最快、存活率高、饲料系数较低。方差分析的结果表明 ,南美白对虾的最适生长盐度范围为 14～ 2 2 (|Xi-Xj|>LSD0 .0 5)。     

温度和盐度对鞍带石斑鱼受精卵发育及仔鱼成活率的影响

研究了在8个盐度梯度(18.3‰、19.7‰、21.2‰、23.5‰、25.6‰、27.1‰、29.5‰和31.7‰)下鞍带石斑鱼Epinephelus lanceol受精卵和仔鱼在水中的分布状态、出膜率和仔鱼存活率;在9个温度梯度(18℃、20℃、22℃、24℃、26℃、28℃、30℃、33℃和35℃)下,其受精卵孵化率、畸形率和仔鱼成活率。结果表明:(1)在水温为25~26℃,当盐度≤25.6‰时,受精卵表现为沉性;当盐度≥27.1‰时,受精卵表现为浮性。仔鱼的分布与受精卵有相似的特点,当盐度≤21.2‰时仔鱼分布在底层水体;当盐度≥27.1‰时,仔鱼集中分布在上层水体。(2)以孵化率和成活率为指标,鞍带石斑鱼孵化的适宜盐度范围为21.2‰~31.7‰,最适盐度范围为25.6‰~31.7‰。在盐度为31.7‰时仔鱼成活率最高达到75.9%。(3)鞍带石斑鱼胚胎发育的适温范围是26~30℃。28℃时受精卵孵化率、仔鱼成活率均最高,畸形率最低。     

壳聚糖对花鲈生长和非特异性免疫力的影响

在基础饲料中分别添加0.5%、1%和2%的壳聚糖,连续投喂花鲈(Lateolabrax japonicus)60d,探讨壳聚糖对花鲈生长和非特异性免疫力的影响。结果表明,添加0.5%和1%壳聚糖可以显著促进花鲈的生长,但是不同添加浓度对成活率均无影响。在30d时添加0.5%或1%壳聚糖能有效提高花鲈的补体活性、溶菌酶活性和吞噬活性;在60d时仅明显提高补体活性。添加壳聚糖对白细胞的数量没有影响。     

复合微生态制剂对花鲈非特异性免疫力及抗病力的影响

将复合微生态制剂以0(control)、500mg/kg(PR-500)和3000mg/kg(PR-3000)的添加量加入到花鲈(Lateolabraxjaponicus)基础饲料中,在饲喂42d和84d后分别取样,以血清溶菌酶活力、替代补体活力(ACH50)、头肾巨噬细胞杀菌力及呼吸爆发活力为判据,确定微生态制剂对花鲈非特异性免疫力的影响;用鳗弧菌Vibrio anguillarum对饲喂84d后的花鲈进行攻毒实验,测定累积死亡率,以确定微生态制剂对花鲈抗病力的影响。结果表明,饲喂84d时,实验组的特定生长率(SGR)较对照组有增高的趋势,但与对照组间无显著性差异(P>0.05)。饲喂42d时,实验组花鲈的血清溶菌酶活力与对照组相比无显著性差异(P>0.05);84d时,实验组的溶菌酶活力显著低于对照组(P<0.05)。饲喂42d与84d时实验组花鲈的替代补体活力(ACH50)与对照组相比无显著性差异(P>0.05);饲喂84d时,实验组花鲈巨噬细胞的呼吸爆发活力与对照组相比无显著性差异(P>0.05);PR-3000组花鲈的巨噬细胞杀菌力显著高于对照组(P<0.05);实验组花鲈的头肾巨噬细胞数量显著高于对照组(P<0.05)。攻毒实验结果显示,对照组花鲈最早出现死亡;攻毒后第27~32h期间,对照组花鲈的累积死亡率显著高于实验组(P<0.05)。     

海鲈游泳续航时间和运动代谢规律研究

为研究海鲈(Lateolabrax japonicus)的游泳续航能力和游泳过程中的物质代谢规律,以深水网箱养殖的3月龄海鲈为研究对象,采用游泳续航时间和生化指标作为评测海鲈游泳能力和代谢规律的方法进行了试验。结果显示,海鲈的游泳续航时长为200 min,其续航能力强于大黄鱼而弱于美国红鱼。在游泳过程中,海鲈血糖浓度升高,但差异性不显著(P>0.05),肌糖原随着时间的增加显著减少(P<0.05),且肌糖原浓度在海鲈疲劳时接近于0。当鱼接近100%疲劳时,其肝糖原浓度也接近于0;当海鲈以不同疲劳程度游泳时,其肌肉乳酸脱氢酶浓度会显著升高(P<0.05)。表明海鲈的续航游泳过程伴随着无氧呼吸和有氧呼吸。     

池养尖吻鲈和花鲈的生长特性

尖吻鲈（Ｌａｔｅｓｃａｌｃａｒｉｆｅｒ）、花鲈（Ｌａｔｅｏｌａｂｒａｘｊａｐｏｎｉｃｕｓ）为河口性鱼类,可作为池塘养殖的对象。尖吻鲈的适宜生长水温为２５℃～３４℃,快速生长年龄在Ⅰ～Ⅱ龄;花鲈在珠江口地区一年四季均能生长,快速生长年龄在Ⅲ～Ⅳ龄。应用ＶｏｎＢｅｒｔａｌａｎｆｙ方程求得它们在人工饲养条件下体长、体重生长方程：尖吻鲈Ｌｔ＝７０６．５５５３［１－ｅ－０．５１２８（ｔ＋０．２０３２）］,Ｗｔ＝６５５４．４６４９［１－ｅ－０．５１２８（ｔ＋０．２０３２）］３．０３３５;花鲈Ｌｔ＝８８７．４９５８［１－ｅ－０．４０２５（ｔ＋０．０２０９）］,Ｗｔ＝１０８８２．１８８４［１－ｅ－０．４０２５（ｔ＋０．０２０９）］３．１４２７。它们的体重生长拐点分别位于１．９６和２．８２龄处。商品鱼的合理起捕时间应选在生长转折点。参照生物学指标,珠江口地区池养尖吻鲈、花鲈的上市商品鱼应为Ⅰ～Ⅱ龄和Ⅲ～Ⅳ龄,这不仅符合经济原则,也适应当地的消费习惯。     

Effects of temperature, salinity and pH on larval growth, survival and development of the sea cucumber Holothuria spinifera Theel

For large-scale seed production of sea cucumbers through a hatchery system, it is imperative to know the effects of environmental parameters on larval rearing. Auricularia larvae (48 h post-fertilization) were obtained from induced spawning of Holothuria spinifera and used in experiments to ascertain the effects of temperature, salinity and pH on the growth and survivorship of the larvae. The larvae were reared for 12 days at temperatures of 20, 25, 28 and 32 °C; salinities of 15, 20, 25, 30, 35 and 40 ppt; and pH of 6.5, 7.0, 7.5, 7.8, 8.0, 8.5 and 9.0. The highest survivorship and growth rate and fastest development of auricularia indicated that water temperature of 28–32 °C, salinity of 35 ppt and pH of 7.8 were the most suitable conditions for rearing larvae of H. spinifera.     

Influence of temperature and salinity on length and yolk utilization of striped bass larvae

The effects of temperature and salinity on yolk utilization and growth of larval striped bass (Morone soxatilis) from Canadian maritime stocks were studied to determine optimal rearing conditions. Larval length increased during yolk utilization and maximum length (L_max) was attained at about 70 degree-days post-hatch. Dry weight declined during yolk utilization, whereas, larval wet weight was relatively constant and only declined when yolk was depleted. Temperature and salinity significantly affected the L_max. Temperatures exceeding 18 C resulted in lower L_max. Higher L_max values were attained at 5 % than at 1 or 10 %. Time to reach L_max was longer at 5 and 10 % than at 1 % for any experimental temperature. Time to reach L_max was 3 days post-hatch longer than times to maximum embryo dry weight. The Q₁₀ of yolk utilization was 1.71, 1.53 and 2.52 at 1, 5 and 10 %, respectively. Times to terminal yolk utilization were about 1.2 d shorter than times to L_max. Morphological changes during yolk utilization indicated rapid development of locomotory and predatory capabilities. These and other developmental strategies were compared to those of salmonids. Rearing striped bass larvae at 14 \-16C and 5 % throughout yolk utilization should result in longer larvae at initial first feeding.     

花鲈对常用饲料原料中氨基酸和磷的利用率研究

试验以Cr2 O3为指示物 ,以 70 %基础饲料和 30 %的待测饲料原料组成试验饲料 ,在室内流水养殖系统中 ,采用虹吸法收集粪便 ,测定了花鲈对红鱼粉、豆粕、花生粕、菜籽粕、肉骨粉和棉籽粕中蛋白质、氨基酸的表观消化率和磷的利用率。在水温 2 5± 1℃的试验条件下 ,花鲈对鱼粉、豆粕、花生粕和菜籽粕的蛋白质的表观消化率都在 80 %以上。花鲈对原料氨基酸表观消化率的变化与对蛋白质表观消化率的变化相一致 ,除了赖氨酸、缬氨酸、蛋氨酸之外 ,对肉骨粉中表观氨基酸的消化率最低。对饼粕类原料中的含硫氨基酸 (如蛋氨酸 )的表观消化率低于其他氨基酸 ,对鱼粉中的组氨酸、对肉骨粉中的苏氨酸利用率最低。花鲈对鱼粉中磷的利用率最高为 85 5 2 % ,而对菜籽粕、肉骨粉和棉籽粕中磷的利用率很低 ,仅为 8 6 9%～ 2 4 82 %。     

Effects of six alternative lipid sources on growth and tissue fatty acid composition in Japanese sea bass (Lateolabrax japonicus)

Ten-week experiment was carried out on Japanese sea bass (5.87 ± 0.02 g) to study the effects of replacement of fish oil with six alternative lipid sources: pork lard, PL; beef tallow, BT; poultry fat, PF; soybean oil, SO; corn oil, CO; and a mixed-fat (MF: tallow, 60%; soy oil, 20%; fish oil, 20%) on growth performance and fatty acid (FA) composition in fillet and liver. Seven isoenergetic and isonitrogenous experimental diets were formulated, containing 10% of added lipid. Fish oil was used in control diet, which was substituted by 50% with the alternative lipid sources in the other six diets.

Weight gain (WG), specific growth rate (SGR), Feed conversion ratio (FCR) feed intake and hepatosomatic index (HSI) of fish fed the experimental diets were not significantly different (P > 0.05). Protein efficiency ratio (PER) in fish fed the PF diet were significantly lower than those of fish fed SO and CO diets. Significant differences in carcass moisture and lipid contents of carcass and liver were observed among fish fed the dietary treatments. Generally, the fatty acid composition of fish fillets and livers reflected the dietary FA composition.