报刊要闻

<正> 水库鲢鳙鱼产力的评估 本文在对辽宁58座水库调查的基础上,根据Fuzzy聚类分析和逐步回归筛选的结果,采取了国内外实践证明效果较好和比较流行的评估鱼产力的模型,以现实连续五年的最高渔获量和浮游生物数据作为自变量,计算了其间的相关显著程度。认为形态土壤学指数(MEI)效果最佳;形态流域指数(MDI)在水库交     

用乳油敌敌畏治疗水库指环虫病的报告

用乳油敌敌畏治疗水库指环虫病的报告王克江，李长林郭万山（抚顺市水产科学研究所１１３００８）（抚顺县英守水库管理所１１３１２２）抚顺县英守水库是一座以防洪、灌溉、养鱼等综合经营的中型水库。总库容１２３７ｍ３，集雨面积５５ｋｍ２，养鱼面积８００亩。多年来...     

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。     

基于栖息地模拟法的中华鲟自然繁殖适合生态流量分析

以长江中华鲟作为目标物种,通过中华鲟自然繁殖期间产卵江段的的栖息地调查,确定了中华鲟的偏好水深、偏好流速及偏好底质。以河道内流量增量法（ＩＦＩＭ）为基础,采用二维水力学模型结合鱼类栖息地模型对中华鲟产卵场的栖息地条件进行了分析,计算了中华鲟自然繁殖期间流量与栖息地加权可利用面积的关系。结果表明,流量在１３０００～１５０００ｍ３／ｓ时,栖息地加权可利用面积达到最大,约２．１ｋｍ２。     

鸭河口水库移植太湖银鱼总结

鸭河口水库移植太湖银鱼总结河南省南阳市水利局（４７３０６２）刘垠，段金平南阳市鸭河渔场陈居明，曹桂华，胡迎新一、鸭河口水库的环境条件及渔业现状鸭河口水库是南阳市一座大型水库，１９５９年建成，水库流域面积３０３０ｋｍ２，多年平均进水量１１．９亿ｍ３，库...     

陡河水库电厂热排水的渔业效应

陡河水库电厂热排水的渔业效应董方勇（水库渔业研究所，武汉４３００７３）关键词热排水，鱼类，电厂，水库ＥＦＦＥＣＴＳＯＦＴＨＥＲＭＡＬＷＡＴＥＲＤＩＳＣＨＡＲＧＥＦＲＯＭＴＨＥＰＯＷＥＲＰＬＡＮＴＯＮＦＩＳＨＥＲＩＥＳＩＮＤＯＵＨＥＲＥＳＥＲＶＯＩＲ￥...     

浑江水库浮游生物调查及鲢鳙鱼产潜力的估算

１９９０年４月至１９９２年１１月，对浑江水库的浮游生物进行了调查，测定结果该水库浮游植物生物量为１．９４１ｍｇ／Ｌ，浮游动物生物量为２．７２６ｍｇ／Ｌ。由此，估算出浑江水库鲢，鳙生产潜力为３７９ｋｇ／ｈａ。本文提出了今后渔业利用意见和增养殖措施。     

福建省水库渔业现状与资源开发

１渔业现状福建省水库渔业始于５０年代末、６０年代初。当时只有少数水库投放鲢、鳙鱼苗，产量低，效益差。１９７９年全省水库鱼产量只有３７５ｔ，３７．５ｋｇ／ｈｍ２，５８座大中型水库养鱼仅有３座盈利。１９８５年产量达到１６３１ｔ，１０２ｋｇ／ｈｍ２，盈利率...     

影响水库鱼产量的生态因子的主成分分析

以我国有代表性的３２座养鱼水库为样本，选取对鱼产量有影响的１５个生态因子作主成分分析。结果表明，在参选的因子中，平均水深（ｘ２）、消落区面积（ｘ３）、水温（（ｘ５）、年降雨量（ｘ６）、溶氧量（ｘ９）、总磷浓度（（ｘ１０）、浮游植物生物量（ｘ１３）和鱼种投放量（ｘ１５）是影响鱼产量的主导因子。这些主导因子可以作为评价水库鱼产量的生态学指标。同时，对主成分分析方法在渔业上的应用进行了讨论     

氯化物水型盐碱池塘的限制性营养盐研究↑（*）

研究了沿黄盐碱地池塘水（ＣｌⅡＮａ 和ＣｌⅢＮａ） 的主要营养盐（Ｎ、Ｐ） 的限制作用和适宜施肥浓度。首次发现该类型池塘普遍表现为氮限制。塘水中无机氮浓度很低,只有（２３ ．５６ ±１２ ．５３） μｇ／Ｌ（ Ｍ±ＳＤ） ,与无机磷的比值仅为１ ．０２ ±０ ．８５ ;而总氮和总磷并不低,分别为（３ ．３５ ±１ ．０８） ｍｇ／Ｌ 和（０ ．２４ ±０ ．１１） ｍｇ／Ｌ;ＴＮ／ＴＰ为１４ ．９４ ±３ ．４３ 。适宜的施肥Ｎ∶Ｐ（ 重量） 为（１０ ～１５）∶１ 。文中提出了１ 种氮限制指数：ＩＮＬ＝ （ＤＯＩＮ１ ．０－ ＤＯＩｃ）／（ＤＯＩＮ１ ．０Ｐ０ ．１ － ＤＯＩｃ） ,并拟合出ＩＮＬ 与ＴＮ／ＴＰ的相关模型,ＩＮＬ 可准确地表示氮限制程度。文章最后分析了氮限制的原因。     

草鱼对饲料中磷需要量的研究

采用酪蛋白—明胶(7:1,W/W)为基础的精制饲料,以磷酸二氢钙作磷源,用梯度法进行草鱼对饲料中磷需要量的试验,证实草鱼的生长受饲料中磷含量的影响较大。饲料中磷不足,草鱼生长缓慢,饲料系数高,整条鱼体水分、灰分、钙、磷和钙磷比低下,脂肪积累,脊椎骨磷含量低下。饲料中磷含量过高引起草鱼生长缓慢,甚至死亡。根据鱼的增重率、饲料系数等分析判断:草鱼饲料中磷的适宜范围为0.95—1.10％,草鱼对饲料中有效磷的需要量为0.85—1.00％。试验表明:草鱼饲料中的盐类添加应以磷为主体。     

鳜鱼、青鱼、草鱼、鲤、鲫、鲢消化酶活性的研究

鳜鱼、青鱼、草鱼、鲤、鲫、鲢肝脏蛋白酶活性低于肠蛋白酶。肠蛋白酶活性，鳜鱼最高，其余依次为青鱼、鲤、鲢、草鱼、鲫。鳜鱼、鲢的肠蛋白酶活性由前肠向后肠递减；而青鱼、鲤、草鱼的则由前肠向后肠递增；鲫则中肠活性最低。六种鱼不同组织的脂肪酶活性因鱼而异。青鱼、鳜鱼、鲤、鲢肝脏中脂肪酶活性低于肠脂肪酶活性（Ｐ＜０．０１）；而草鱼和鲫肝脏中脂肪酶活性与肠脂肪酶活性差异不明显（Ｐ＞０．０５）。六种鱼肝脏中脂肪酶活性由高到低依次为鳜鱼＞鲢＞鲫＞草鱼＞青鱼＞鲤；肠脂肪酶活性顺序为鳜鱼＞鲢＞青鱼＞鲤＞草鱼＞鲫。脂肪酶活性与鱼类食性无明显相关性。不同组织间淀粉酶活性存在差异。鳜鱼的肝脏和肠均有较高淀粉酶活性，青鱼和鲫肝脏中淀粉酶活性低于肠中的；草鱼、鲤和鲢肝脏中淀粉酶活性高于肠中的，但差异不显著。六种鱼中鳜鱼的肝脏淀粉酶活性明显高于其它五种无胃鱼，它们的淀粉酶活性顺序依次为鳜鱼＞鲢＞鲤＞草鱼＞青鱼＞鲫；肠淀粉酶活性顺序为鳜鱼＞鲫＞鲤＞青鱼＞鲢＞草鱼。     

Effects of feeding rates on growth and production of Nile tilapia, common carp and silver carp polycultured in fertilized ponds

Abstract In an attempt to identify appropriate feeding rates for multispecies of fish raised in fertilized earthen ponds, the present work was conducted over a 19‐week experimental period to establish the growth performance, production and body composition of Nile tilapia, common carp and silver carp fed 0.0%, 0.5%, 1.0%, 3.0%, 5.0% biomass and to apparent satiation (treatments). Twelve ponds were stocked with a similar number and weight of each fish species. Two ponds were assigned to each of the treatments, and a 25% protein pelleted fish feed was used to feed fish at the specified rate of feeding. At the end of the experiment, growth, weight gain, survival, yield and body composition of fish groups were affected by the treatments. The economic effectiveness also varied among treatments. The most conspicuous attribute of the feeding rates was its lack of influence on growth (g day^?1), weight gain (g per fish), yield (kg ha^?1) or body composition of silver carp. The results of whole‐body proximate analysis indicated that various feeding rates had either an irregular pattern or no effects on the protein and ash gain per 100 g of fish body weight (bw) gain. The most notable exceptions were significant (P < 0.05) increases in body fat and gross energy gains in Nile tilapia, common carp and silver carp accompanied by decreases in percentages of moisture (but not in silver carp) as feeding rate increased. Among the six different feeding levels, feeding to apparent satiation (feed amount was equivalent to 2.67% of fish bw day^?1) appeared to be optimal, as it significantly (P < 0.05) supported the highest fish production, income and net profit compared with all other treatments except for the 3% feeding level, for which the differences in those measurements were comparable.     

异育银鲫溶血性腹水病的组织显微病理研究

本文报导了1986年以来，在上海郊县及江苏等省市引起异育银鲫大量死亡的疾病、目前在国内外尚未见有报导，是一种新的暴发性鱼病。为此我们进行了病鱼组织显微病理变化的观察。现将该病暂定名为异育银鲫溶血性腹水病。病鱼体表充血、出血，病情严重时肛门红肿，眼球突出，腹部膨大，腹腔内有淡黄色或红色腹水，肠壁充血发炎；有的病鱼骨骼肌也充血，鳞片竖起。各组织器官都发生病变，其中尤以肝、脾、肾为严重；肝脏肿大，质地极度柔软，呈弥漫性坏死，肝细胞的胞浆内有被苏木素深染的丝状物；脾脏大片坏死解体成淡红色一片；肾小体坏死，以至解体，肾小管及造血细胞也多数发生病变，并有细胞管型．     

三种鲫鱼对暴发性鱼病的抗病力

本文报道彭泽鲫、异育银鲫及白鲫对嗜水气单胞菌引起的暴发性鱼病抗病力的研究结果。在菌液浓度为6.0×10~6个/ml,注射剂量为0.3ml/尾时,半数致死量(LD_(50))分别为彭泽鲫 10~(-1.?),异育银鲫 10~(-1.61),白鲫 10~(-2.21),差异极显著(P<0.01)。从三个方面进一步研究了造成以上差异的机理:(1)补体总量——彭泽鲫 6.40 单位/ml,异育银鲫 5.97 单位/ml,白鲫 2.20 单位/ml,差异极显著(P<0.01);(2)补体替代途径(C_d 旁路)杀菌能力——彭泽鲫和异育银鲫极显著优于白鲫(均值多重分析 D>D_(0.01)),彭泽鲫好于异育银鲫,但差异不显著;(3)白细胞吞噬功能——三种鲫鱼间存在极显著差异(P<.01),吞噬百分率是彭泽鲫极显著优于白鲫和异育银鲫(D> D_(0.01)),吞噬指数是彭泽鲫和异育银鲫显著优于白鲫(D>D_(0.05))。彭泽鲫是对暴发性鱼病抗病力较强的品种,白鲫是对暴发性鱼病抗病力最差的品种。     

THE IMPACT OF PRICE AND YIELD RISK ON THE BIOECONOMICS OF RESERVOIR AQUACULTURE IN NORTHERN VIETNAM

A bioeconomic model of reservoir aquaculture in northern Vietnam is used to investigate the impacts of fish price and yield variability on the level and riskiness of expected net revenue. Net revenue is volatile compared with similar enterprises in other countries, mainly due to high yield variability. This reflects the nascent nature of the industry in Vietnam and the potential for efficiency and productivity improvements. Increasing production intensiveness, as well as reservoir size, was found to increase profits and decrease revenue risk. Among the management parameters studied, expected net revenue was found to be most sensitive to the length of the production cycle and to the harvest rate, while revenue risk was most sensitive to cycle length. Reservoir size was found to affect net revenue less than anticipated. Although common carp monoculture was found to maximize expected profit, the current species mix minimizes risk, thereby suggesting high risk aversion by northern Vietnam's poor farmers.     

Use of Hydrolysates from Silver Carp (Hypophthalmichthys molitrix) Head as Peptone for Vibrio anguillarum and Optimization Using Response Surface Method (RSM)

The objective of this study was to produce fish peptone (FP) from silver carp (Hypophthalmichthys molitrix) heads by Alcalase® hydrolysis in order to use for growing Vibrio anguillarum instead of the standard peptones applied in the commercial media. An optimization of the FP to be used as culture media was also carried out using the response surface method (RSM). According to the results, the degree of hydrolysis and protein percentage after 24 h was 37.68 mg/mL and 20.74%, respectively. The adjustment of the quadratic model with the experimental data was satisfactory. The analysis of variance showed a high coefficient of determination value (0.930). The results of fish protein hydrolysates also showed that fish by-products modified by enzymatic procedures can be used as low cost nitrogen sources for bacterial growth.     

The Impact of Nutrient Concentration (N:P) and Manure Type on Fish Polyculture

Abstract

Nutrient availability is considered to have a major role in controlling primary productivity. Therefore, an important aspect of successful aquaculture management in fish culture systems is making available basic nutrients, for example, phosphorous (P), nitrogen (N), and carbon (C) in optimal concentrations. The use of fertilizers in relation to pond productivity has been studied in order to develop better fertilization procedures under given environmental conditions. Many researchers from across the world have suggested different N:P ratios for optimizing fish production. The primary aim of this study was to understand the influence of nutrient quality and quantity on fish and primary productivity in terms of optimizing fish production. Two objectives of this study include evaluating the performance of pig and cow manures in terms of primary productivity and fish production; and understanding the influence of different N concentrations ranging from 1-2 ppm on fish production while P was maintained at 0.5 ppm. It was evident from this research that fish species nutrient-sensitivity to nitrogen concentrations ranging from 1-2 ppm was significantly different. The 1 ppm N:0.5 ppm P concentration was found to be the most suitable nutrient ratio for pond fertilization as significantly higher fish production and lower mortality were recorded in this treatment. In terms of plankton and fish production, pig manure was found to be significantly more effective than cow manure. Higher nutrient (>1 ppm N) concentrations negatively impacted zoo-plankton and zoo benthos development. Daily manure application would considerably reduce the organic load in the fish culture system, enabling more efficient use of nutrients for primary and secondary production.     

Measurement of total body composition changes of common carp by computer tomography

The crude fat and protein content of the total body was estimated by X‐ray computer tomography (CT) and determined by chemical analyses during a feeding experiment with sexually matured common carp. Between 21 and 35 serial scans were taken of altogether 41 fish and samples from the homogenized body were prepared for chemical analyses. Experimental fish with an average body weight of 1453 g originated from a commercial stock of mirror carp. Two feeding regimes (carp feed and carp feed+ad libitum maize) were applied for 57 days and followed by a fasting period of 27 days. Both feeding regimes significantly increased the crude fat content of the whole body that did not decrease during fasting in spite of high water temperature (22°C). No significant changes were observed in crude protein content. The variables used for producing the prediction equations were taken from the density values of the Hounsfield scale, on a range between ?90 and +160, by summing the frequencies within each interval of 10 values. Whole body fat content could be estimated with R²=0.89?0.91 accuracy with the principal component analysis using data of all (seven) body regions and only dorsal fin region respectively. Adequate linear regression model could not be calculated by the same procedure for crude protein. Three‐dimensional ‘volumetric’ estimation of fat tissue was also carried out on the basis of fat index showing high correlation with measured fat content. The changes of body composition of individual fish can be followed by sequential CT scanning.     

Covariation between the average lengths of mature coho (Oncorhynchus kisutch) and Chinook salmon (O. tshawytscha) and the ocean environment

We used the average fork length of age‐3 returning coho (Oncorhynchus kisutch) and age‐3 ocean‐type and age‐4 stream‐type Chinook (Oncorhynchus tshawytscha) salmon along the northeast Pacific coast to assess the covariability between established oceanic environmental indices and growth. These indices included the Multivariate El Niño‐Southern Oscillation Index (MEI), Pacific Decadal Oscillation (PDO), Northern Oscillation Index, and Aleutian Low Pressure Index. Washington, Oregon, and California (WOC) salmon sizes were negatively correlated with the MEI values indicating that ultimate fish size was affected negatively by El Niño‐like events. Further, we show that the growth trajectory of WOC salmon was set following the first ocean winter. Returning ocean‐type British Columbia‐Puget Sound Chinook salmon average fork length was positively correlated with the MEI values during the summer and autumn of return year, which was possibly a result of a shallower mixed layer and improved food‐web productivity of subarctic Pacific waters. Size variation of coho salmon stocks south of Alaska was synchronous and negatively correlated with warm conditions (positive PDO) and weak North Pacific high pressure during ocean residence.