大西洋鲑循环水养殖水体异养细菌组成的研究

采集养殖池水样,选取Zobell 2216E琼脂培养基、溶菌肉汤琼脂培养基、硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基、脑心浸液琼脂培养基、胰蛋白胨大豆琼脂培养基、营养琼脂培养基6种常见固体培养基进行细菌分离培养,以平板菌落计数法和菌落外观形态特征辨别及16SrRNA基因测序方法进行异养菌计数和种类组成分析。结果显示:(1)养殖池水体异养菌可分为4大类,分别属于变形菌门(包括α-、γ-变形菌纲)、厚壁菌门、拟杆菌门、放线菌门,其中以γ-变形菌纲为优势菌群。按属分类大多为假交替单胞菌属和弧菌属。(2)不同培养基分离菌落数量2216E培养基溶菌肉汤琼脂培养基胰蛋白胨大豆琼脂培养基脑心浸液琼脂培养基营养琼脂培养基硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基,且2216E培养基菌落数极显著高于其余5种培养基(P0.01);2216E培养基所分离细菌的种类最多,分属于12个属,假交替单胞菌属为优势类群,占比50%,弧菌属仅占3.13%;脑心浸液琼脂培养基、溶菌肉汤琼脂培养基、胰蛋白胨大豆琼脂培养基所分离细菌均以弧菌属为优势菌群,分别占33.33%、60%、25%;硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基所分离细菌仅分属于1个属,即弧菌属;营养琼脂培养基无弧菌,但有假单胞菌分离出。     

不同光照条件对浮游植物生物量与多样性的影响

通过构建光照强度与浮游植物生物量和群落结构特征参数的关系曲线,为三峡水库水华预测预报模型的构建提供基础数据,同时也为水库调度的方案提供理论依据。基于三峡水库野外原位观测数据的分析结果,针对性设计不同梯度光照强度下浮游植物的生长演替规律室内控制实验。结果表明:(1)光照是影响浮游植物生物量和多样性的关键要素,光照强度0~4 500 lx,浮游植物的生物量随着光照强度的增加而增加,在光照强度为4 500 lx时,浮游植物生物量达到最大,但光强超过4 500 lx之后,浮游植物的生物量随着光照强度的增加而减少;光照强度0~1 500 lx,浮游植物群落多样性随着光强的增加而增加,在光照强度为1 500 lx时,浮游植物群落多样性达到最大;光照强度1 500~4 500 lx,浮游植物群落多样性随着光照强度的增加而减少;当光强超过4 500 lx,浮游植物群落多样性随着光照强度的增加而增加;(2)从制定三峡水库生态调度方案的角度来看,当光照强度在1 500 lx时,浮游植物生物量达到最低,此时其群落多样性达到最大,为最佳的调度方案光照参数;(3)浮游植物生物量(y)与光照强度(x)的关系为:y=2×10~(-8)x~3-5×10~(-4)x~2+3.1923x-122.92(R~2=0.934,P0.01),两者极显著相关;多样性指数(y)与光照强度(x)的关系式为:y=2×10~(-12)x~3-3×10~(-8)x~2+10~(-4)x+0.3266(R~2=0.554,P0.01),两者极显著相关。     

2003年春季东海区浮性鱼卵和仔稚鱼种类组成及数量分布

本文分析研究了2003年春季东海区(27°00′～34°00′N)150m以浅海域浮性鱼卵、仔稚鱼的种类组成及数量分布。共鉴定49种鱼类的鱼卵、仔稚鱼,其中31种鉴定到种,隶属于26科、29属。优势种类为日本鳀、方氏云鳚、太平洋鲱。带鱼、小黄鱼等经济鱼类鱼卵、仔稚鱼数量少,鲱形目鱼类鱼卵、仔稚鱼数量较多。鱼卵、仔稚鱼分布主要在近海禁渔线附近海域。     

Effects of dietary fish oil replacement with blended vegetable oils on growth,lipid metabolism and antioxidant capacity of subadult swimming crab Portunus trituberculatus

A 120‐day trial was conducted to assess the effects of dietary fish oil replacement with vegetable oils on growth, lipid metabolism and antioxidant capacity of subadult swimming crab Portunus trituberculatus. Five isonitrogenous and isolipidic diets were formulated to replace 0, 250, 500, 750 and 1000g/kg of fish oil with a mixture of soybean and rapeseed oil (defined as D1–D5), and each treatment had 30 replicate crabs. Dietary fish oil replacement had no significant effects on growth of the crabs, while the D3 had the highest hepatosomatic index and total lipids in hepatopancreas. The triglyceride and lipase activities in hepatopancreas increased significantly with increasing dietary fish oil replacement. The D4 had the highest levels of alkaline phosphatase (ALP) and acid phosphatase (ACP) in the hepatopancreas, as well as the haemolymph ALP, ACP and peroxidase. The highest levels of haemolymph total antioxidant capacity, catalase and malondialdehyde were detected in D1. Total n‐3 polyunsaturated fatty acids levels in hepatopancreas decreased significantly with increasing dietary fish oil replacement. In conclusion, dietary fish oil replacement had no significant effects on growth of P. trituberculatus, and 500g/kg of fish oil replacement could improve antioxidant capacity, but excessive replacement level will enhance lipid accumulation and peroxidation in the hepatopancreas.     

Dry whey meal as a protein source in practical diets for Nile tilapia,Oreochromis niloticus fingerlings

ABSTRACT

This study was conducted as a trial of using dry whey meal (DWM) as a substitute for fish meal (FM) in practical diets for Nile tilapia, Oreochromis niloticus. Triplicate fish groups were fed on five isonitrogenous (30.2%) and isolipidic (6.9%) diets. The control diet (D1) used FM as the sole protein source. In the other four diets (D2–D5), FM protein was substituted by 25, 50, 75, or 100% DWM. Fish (3.5 ± 0.1 g) were stocked at a rate of 20 fish per 100-L aquarium and fed one of the tested diets up to satiation twice daily for 12 weeks. Fish growth, feed utilization, protein efficiency ratio, apparent protein utilization, and energy utilization for fish fed DWM diets up to 75% FM (D2–D4) tended to be higher but were not statistically different than the control diet. No significant effect of diet was found in whole-body moisture, crude protein, and total ash contents. Whole-body lipid content in fish fed the 100% DWM (D5) diet was significantly higher than that for fish fed the control diet. The optimal replacement level of FM by DWM was estimated by second-order polynomial regression to be 62.5%.     

池塘养殖和野生长江水系中华绒螯蟹扣蟹形态学及生化组成的比较研究

采用形态学测量和生化分析等方法,比较了野生和池塘养殖条件下长江水系中华绒螯蟹扣蟹的形态学、肝胰腺指数(HSI)、常规生化组成和脂肪酸组成。结果发现:野生和池塘养殖扣蟹的形态学特征差异较大,雌雄个体均有4个贡献较大的主成分(PC1,PC2,PC3,PC4),其中PC1的贡献率均远高于其他主成分,两者PC1分别由16和19个主要影响变量构成;所测36个形态学指标中,两群体雄蟹和雌蟹分别有25和22个形态学指标差异显著,进一步筛选判别贡献率较大的4~5个指标分别建立判断方程,综合判别准确率达95%以上;野生扣蟹的HSI、组织中总脂、躯体肌肉的16:0、18:1n9和20:4n6含量均高于池塘养殖扣蟹,后者组织中水分含量、躯体肌肉中的18:0、20:5n3和22:6n3高于前者。研究表明,野生和池塘养殖扣蟹的形态学和生化组成均存在较大差异,可以根据两群体扣蟹的形态学差异和判别方程鉴别两种扣蟹蟹种。     

新疆阿勒泰地区不同水体浮游生物种群特点的初步研究

１９８６—１９８９年调查了新疆阿勒泰地区３０处不同水体的浮游生物。浮游植物以硅藻为主，占５９．２％，浮游植物季节变化呈单峰型。湖泊、水库、坑塘和河流的浮游植物生物量分别为４．３５９ｍｇ／Ｌ、２．７０６ｍｇ／Ｌ、６．２３１ｍｇ／Ｌ和１．９７６ｍｇ／Ｌ，浮游动物生物量分别为３．３２ｍｇ／Ｌ、３．７７３ｍｇ／Ｌ、１．８５９ｍｇ／Ｌ和０．５４４ｍｇ／Ｌ。全区湖泊、水库、坑塘浮游生物产量为９９０９６．７１Ｔ，鱼产潜力４３９８２．４Ｔ。讨论了水体营养类型的划分和渔业利用问题。     

Effects of varying dietary compositions using common feed ingredients on growth and feed efficiency of pond‐raised channel catfish Ictalurus punctatus (Rafinesque)

Two experiments were conducted to evaluate various ingredient combinations in a 28% or 32% protein diet for optimum performance of channel catfish Ictalurus punctatus. All diets contained soybean meal and corn, but with or without cottonseed meal, wheat middlings or fish meal (FM). Channel catfish fingerlings were stocked into 0.04 ha earthen ponds at 18 530 fish ha^?1. Fish were fed one of eight diets once daily to apparent satiation for two growing seasons. Results demonstrated that the dietary ingredient composition used had significant effects on fish performance, but magnitude of differences was relatively small. Overall, diets containing FM resulted in greater weight gain (Experiments 1 and 2) and lower feed conversion ratio (Experiment 1) than fish fed all‐plant diets. However, certain combinations of plant ingredients provided the similar fish growth as some diets containing FM. There were no significant differences in weight gain between fish fed soybean meal–corn or soybean meal–corn–wheat middlings‐based diets with cottonseed meal or FM. The use of wheat middlings in the diet had no significant effects on fish production characteristics.     

不同种类碳水化合物对吉富罗非鱼生长性能、体组成和血清生化指标的影响

为了解罗非鱼对不同种类碳水化合物(CBH)的利用效果,研究了6种碳水化合物对罗非鱼生长性能、体组成和血清生化指标的影响。实验选用720尾初重为(3.0±0.3)g的健康吉富罗非鱼,随机分为6组,每组4个重复,每个重复30尾,分别投喂设计含30%南方糙米、次粉、玉米淀粉、马铃薯淀粉、甘薯淀粉和木薯淀粉的6种不同CBH的等氮、等能饲料,实验周期为8周。结果显示,南方糙米、玉米淀粉组的终末均重、增重率、特定生长率和蛋白效率显著高于其他组,而饲料系数明显最低(P0.05)。CBH种类明显影响全鱼、肌肉的组成(P0.05)。玉米淀粉组肝糖原含量明显高于马铃薯淀粉、甘薯淀粉和木薯淀粉组(P0.05),而马铃薯淀粉和甘薯淀粉组的血糖明显低于木薯淀粉、玉米淀粉和次粉组(P0.05)。CBH种类对血清CHO、TG影响明显(P0.05),但对TP、SOD、T-AOC和MDA的影响不明显(P0.05)。研究表明,不同种类CBH对罗非鱼生长性能的影响明显(P0.05),以特定生长率为指标,罗非鱼对南方糙米和玉米淀粉的利用效果较好。     

几种诱食剂对凡纳滨对虾生长、血清生化指标和肝胰腺消化酶的影响

在基础饲料中添加0.03%核苷酸、0.03%核苷酸+0.2%丙氨酸+0.2%甘氨酸、0.2%甘氨酸、0.2%柠檬酸+0.2%甘氨酸,饲养凡纳滨对虾(Litopenaeus vannamei)6周,研究一种及几种组合型诱食剂对其生长、血清生化、肝胰腺消化酶以及抗氧化能力的影响。结果显示,饲料中添加0.03%核苷酸+0.2%丙氨酸+0.2%甘氨酸能显著提高凡纳滨对虾的增重率、特定生长率和日摄食率(P<0.05);饲料系数以及对虾的成活率不受添加这几种诱食剂的影响(P>0.05)。各组全虾粗蛋白和灰分含量差异不显著(P>0.05);添加0.2%甘氨酸全虾粗脂肪含量显著高于其它各组(P<0.05)。对虾血清中总蛋白、胆固醇、血糖、谷草转氨酶(AST)以及谷丙转氨酶(ALTc)的组间差异不显著(P>0.05)。对虾肝胰腺中脂肪酶活力在添加0.03%核苷酸最高,显著高于0.2%甘氨酸组;各组间淀粉酶活力差异不显著(P>0.05)。对虾血清中总抗氧化能力以添加0.2%柠檬酸+0.2%甘氨酸最高,与其它各处理差异显著(P<0.05)。结果表明,核苷酸与氨基酸的复合应用比单独添加核苷酸或氨基酸能显著提高凡纳滨对虾的摄食、生长以及抗氧化能力;在饲料中建议添加0.03%核苷酸+0.2%丙氨酸+0.2%甘氨酸。