铬盐对鲤生长和饲料转化率的影响

以０．５ｍｇ／ｋｇ铬盐饲料饲喂１龄鲤６５ｄ和３月龄鲤３０ｄ，相对生长率分别提高１３．７９％和２０．６９％饲料转化率提高２１．８３％和２６．０％。表明铬盐有促进鱼类生长作用和提高饲料转化率的效应，而铬盐对鱼体营养成分的作用不明显。但铬盐对对高血糖症鱼的作用是低剂量各（２．５μｇ／ｋｇ体重）使血糖明显下降，高剂量（６０μｇ／ｋｇ体重）则使血糖明显升高；铬盐含量０．５ｍｇ／ｋｇ饲料使高血糖症鱼的血糖下降     

5种常见鱼药治疗剑尾鱼聚缩虫病的研究

用５种药物治疗剑尾鱼聚缩虫病试验，结果呋喃唑酮无效，硝酸亚汞（１． ２５ ±０． ２５） ｍｇ／Ｌ、硫酸铜酸亚铁（５：２）合剂（８．５±０．５）ｍｇ／Ｌ、甲醛（３０±５）ｍｇ／Ｌ、孔雀石绿（０． ９ ± ０． １） ｍｇ／Ｌ对聚缩虫杀死率均在 ９５％以上；治愈率依次为：（９２．５ ± ２．５）％、１００％、（８７．５±２．５）％、（８２．５±２．５）％；剑尾鱼对药物的敏感性强度为孔雀石绿＞硝酸亚汞＞硫酸铜合剂＞甲醛，安全浓度依次为：０．３２、０．４８、４． １、９．４ ｍｇ／Ｌ。表明治疗剑尾鱼聚缩虫病用硫酸铜合剂（８． ５ ± ０． ５） ｍｇ／Ｌ、甲醛（３０ ± ５） ｍｇ／Ｌ浸泡效果好。     

莺河一库渔业潜力及开发对策

对莺河一库水质的调查分析和饵料生物的定量测定得出：该库属中营养型水库，浮游植物初级生产力平均２３．９６ｋｇＯ＿２／ｈａ·ｄ，其中鱼类生长期内初级生产力３２１．１６ｋｇＯ＿２／ｈａ·ｄ，净生产量２５．７３ｋｇＯ＿２／ｈａ·ｄ，净生产量之和为５４０３．３ｋｇＯ＿２／ｈａ，折合浮游植物鲜重为２８６３７．５ｋｇ／ｈａ；浮游植物、浮游动物和底栖动物的生物量分别为３．２ｍｇ／Ｌ、１．２６ｍｇ／Ｌ和０．８５ｇ／ｍ￣２，水库近期鱼产力为３６３．６ｋｇ／ｈａ，总产量２０．９４万ｋｇ。该库历年平均成鱼单产为８８．４ｋｇ／ｈａ，占估算鱼产力的２４．３％，水库的渔业潜力有待开发利用，因此，提出了今后合理开发水库渔业资源的对策。     

常见水产动物疾病的中草药防治方法介绍（下）

（三）真菌病的防治１－水霉病的防治（１）每亩用菖蒲２－５～５ｋｇ，食盐０－５～１ｋｇ，加入人尿２～５ｋｇ，全池泼洒。（２）用五倍子全池泼洒，使池水呈４ｍｇ／Ｌ浓度。（３）桐树叶（或芝麻秆）扎成小捆，放入池中。（４）用２～４ｍｇ／Ｌ的烟茎浸出液，浸洗病鱼３０分钟。（５）全池泼洒２ｍｇ／Ｌ苦楝和０－４ｍｇ／Ｌ碳酸钠。２－鳃霉病的防治用１００ｋｇ芭蕉心（大蕉心或香蕉心）切碎加食盐３～４ｋｇ，再加乐果１００ｇ拌匀，上食台投喂，每１００ｋｇ鱼喂上述混合饲料５ｋｇ，效果较好。（四）寄生虫病的防治１－车轮虫病…     

湖泊网箱养殖名优鱼高产技术研究

１９９８￣１９９９年，在沅江市榨南湖渔场的榨南湖水域，开展了湖泊鳜鱼、草鱼、团头鲂、湘鲫等名优鱼网箱养殖。１９９８年，７０只网箱总产商品鲁６０５３３ｋｇ，平均净单产３０．９ｋｇ／ｍ＾２，产值３６５．２元／ｍ＾２，利润１３４．５元／ｍ＾２，投产比１：１．５８；１９９９年，９０只网箱总产商品鱼１１１１４９ｋｇ，平均净单产３６．７ｋｇ／ｍ＾２，产值４４５．１元／ｍ＾２，利润１５１．２元／ｍ＾２，投产比１     

湖泊网箱养殖名优鱼高产技术研究

１９９８￣１９９９年，在沅江市榨南湖渔场的榨南湖水域，开展了湖泊鳜鱼，草鱼、团头鲂，湘鲫等名优鱼网箱养殖。１９９８年，７０只网箱总产商品鱼６０５３３千克，平均净单产３０．９ｋｇ／ｍ＾２，产值３６５．２元／ｍ＾２，利润１３４．５元／ｍ＾２，投产比１：１．５８；１９９９年，９０只网箱总产商品鱼１１１１４９ｋｇ平均净单产３６．７ｋｇ，产值４４５．１元／ｍ＾２，利润１５１．２元／ｍ＾２，投产比１：１．５１     

乳山湾海水,底质及贝类体内砷的研究

通过１９９５年６－９月对乳山湾的综合调查，初步摸清了乳山湾海水，底质及贝类体内砷的分布。该水域内砷的浓度范围为０．７２－６．８０μｇ／Ｌ，其平均值为１．９４μｇ／Ｌ；底质中砷的含量范围为５．０－９．６ｍｇ／ｋｇ，平均值为７．７７ｍｇ／ｋｇ；     

北民湖自然资源的调查及渔业开发初探

１９９０年，调查了北民湖（１４６７ｈｍ２）的水质，水生生物等情况，该湖氮、磷营养缺乏（ＴＮ１．１８３０ｍｇ／ｌ，ＴＰ０．０２０１５ｍｇ／ｌ），ＴＮ∶ＴＰ＝５８．７１∶１，为浮游生物生长限制因子，折算产鱼潜力为３１．６２ｋｇ／ｈｍ２，通过人工定点施化肥，使其ＴＮ，ＴＰ达到２．０５８４ｍｇ／ｌ，０．２１４５ｍｇ／ｌ，ＴＮ∶ＴＰ＝９．６∶１，投放鱼种３７．５ｋｇ／ｈｍ２，年产鱼２８４．０４ｔ，折合１９３．６ｋｇ／ｈｍ２，为１９８９年鱼产量２８．６４ｋｇ／ｈｍ２的６．７６０倍。     

洪门水库渔业资源调查报告

洪门水库为江西第二大水库，可养鱼面积７．６５万亩，消落区面积２－３万亩，浮游植物生物量４．４０６ｍｇ／Ｌ，浮游动物生物量２．４５ｍｇ／Ｌ。初步估算，水库鱼产力在３１．３６ｋｇ／亩，而目前单产水平保持在１６．６ｋｇ／亩上下。渔获量以镛鱼为方，鲢鱼次之。全库鱼类９６种，经济鱼类占８５％，如适度开发，水库鱼产力将明显提高。     

乌鱼,青虾两茬养殖技术

一、乌鱼养殖阶段１．放养情况池塘面积５亩。１９９９年２月２５日从浙江购进乌鱼鱼种５２５ｋｇ，计３６００尾，作为主养鱼，同时搭配放养花鲢３００尾，银鲫５００尾。具体放养如表１：２．日常管理鱼种到塘口后，用孔雀石绿４－５ｍｇ／Ｌ溶液没洗鱼体１０－１５分钟后下塘。从４月１８日开始每天投喂小鱼１５－２０ｋｇ，每天一次，以后看鱼的摄食情况酌情加量，８月份为最高峰，每天投喂１２５ｋｇ。总计共投喂小鱼１０５５５ｋｇ。月投喂记录如表２：７月１１日用“鱼杀康”全池泼洒用以防病，７月２５日，由于投喂量大，池水腐殖质…     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

美人鱼发光杆菌对凡纳滨对虾非特异性 免疫功能及抗病力的影响

在基础饲料中分别添加0.1%和1%美人鱼发光杆菌灭活菌、0.1%美人鱼发光杆菌活菌配制成3种免疫实验饲料,以基础饲料为空白对照组饲料,每组设3个平行样。对个体质量为(4.83±0.36)g的凡纳滨对虾进行为期20 d的饲养实验,分别在0、5、10、15和20d进行取样,以血清中的酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)和溶菌酶(UL)活性为免疫指标,探讨了美人鱼发光杆菌作为免疫制剂对凡纳滨对虾非特异性免疫效应的影响;在投喂免疫饲料后的第22天,按0.004 2 kg/kg体重的剂量,直接投喂对虾白斑综合征病毒(WSSV)病料,并记录累积死亡率。结果表明,美人鱼发光杆菌免疫实验组对凡纳滨对虾血清中PO、ACP、AKP、UL和SOD活性影响明显高于对照组,并且在饲料中添加美人鱼发光杆菌后,明显提高了对虾抵御WSSV感染的能力。其中0.1%美人鱼发光杆菌活菌实验组的抗病毒感染能力最强,WSSV感染14d内累计死亡率为63.3%±5.8%;而对照组为96.7%±3.3%。研究表明,美人鱼发光杆菌添加在对虾饲料中能提高凡纳滨对虾非特异性免疫水平,增强抵抗疾病的能力,将其作为对虾免疫增强剂具有良好的应用前景。     

Effects of Spirulina platensis as a feed additive on growth and coloration of blue dolphin cichlids (Cyrtocara moorii Boulunger, 1902)

This study was carried out to investigate the effects of replacing fish meal with dietary Spirulina as a feed supplement on the growth performance and coloration of blue dolphin cichlids (Cyrtocara moorii). Five isonitrogenous (47% crude protein) and isocaloric (17.36 kJ/g digestible energy) diets were for formulated to replace FM with 0, 5, 10, 15 and 20% Spirulina (designated as Control, SP5, SP10, SP15 and SP20 respectively) and fed to the fish (initial body weight, 3.15 ± 0.01 g). Fish were randomly distributed into fifteen 120 L aquariums (26.5 ± 1.00°C), 15 fish per aquarium. The diets were tested in triplicate for 12 weeks. Experimental groups were fed twice daily (09:00 and 17:00) by hand to satiation. At the end of the feeding trial, significantly (p < 0.05) higher weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and lower feed conversion ratio (FCR) were observed in fish fed the SP10 diet when compared to the SP20 diet. There was no significant difference in these parameters between the other groups. The skin coloration of blue dolphin cichlid fed a diet containing Spirulina meal was enhanced. The best coloration was observed in the SP15 group. These impressions were objectively validated by chemical determinations of carotenoids extracted from fish skins and passed statistical tests of significance. The study findings show that Spirulina meal does not diminish growth rates except at very high levels.     

Sea bream culture in Egypt; status, constraints and potential

Marine fish farming in Egypt began in 1976 with the culture of gilthead sea bream, (Sparus aurata) as this fish was notably adaptable to brackish and marine pond conditions. Today, marine fish and shrimp farms amount to about 19,000 ha, out of which 42% is already in production while the rest, i.e., 58% is still under construction. In 1997, cultured gilthead sea bream production of 2,250 tons made up 3% of the 75,000 tons total aquaculture catch. In polyculture, usually with the grey mullet and sea bass, gilthead sea bream contributed 440 kg ha^–1 to the total yield of 1,700 kg ha^–1 (26%) over a period of 16 months. For the same period, the yield of monoculture ponds averaged 100 kg ha^–1, while in marine cages, yields ranged from 4–10 kg m³. In 1996–1997, fry of 0.25–1 g and fingerlings 1–10 g with a total of 3 million, were collected from the wild and 1 million fry were produced in the three marine hatcheries out of the four existing ones. The development of sea bream culture in Egypt is now severely inhibited by the shortage of seeds and adequate feeds. Exports of both sea bream and sea bass, during 1994–1996 averaged 1,300 tons per year.     

Dietary thiamin and pyridoxine requirements of fingerling Indian major carp,Cirrhinus mrigala (Hamilton)

Two experiments were conducted to quantify the dietary thiamin (experiment I) and pyridoxine (experiment II) requirements of fingerling Cirrhinus mrigala for 16 weeks. In experiment I, dietary thiamin requirement was determined by feeding seven casein–gelatin‐based diets (400 g kg^?1 CP; 18.69 kJ g^?1 GE) with graded levels of thiamin (0, 0.5, 1, 2, 4, 8 and 16 mg kg^?1 diet) to triplicate groups of fish (6.15 ± 0.37 cm; 1.89 ± 0.12 g). Fish fed diet with 2 mg kg^?1 thiamin had highest specific growth rate (SGR), protein retention (PR), RNA/DNA ratio, haemoglobin (Hb), haematocrit (Hct), RBCs and best feed conversion ratio (FCR). However, highest liver thiamin concentration was recorded in fish fed 4 mg thiamin kg^?1 diet. Broken‐line analysis of SGR, PR and liver thiamin concentrations exhibited the thiamin requirement in the range of 1.79–3.34 mg kg^?1 diet (0.096–0.179 μg thiamin kJ^?1 gross energy). In experiment II, six casein–gelatin‐based diets (400 g kg^?1 CP; 18.69 kJ g^?1 GE) containing graded levels of pyridoxine (0, 2, 4, 6, 8 and 10 mg kg^?1 diet) were fed to triplicate groups of fish (6.35 ± 0.37 cm; 1.97 ± 0.12 g). Fish fed diet containing 6 mg kg^?1 pyridoxine showed best SGR, FCR, PR, RNA/DNA ratio, Hb, Hct and RBCs, whereas maximum liver pyridoxine concentration was recorded in fish fed 8 mg kg^?1 dietary pyridoxine. Broken‐line analysis of SGR, PR and liver pyridoxine concentrations reflected the pyridoxine requirement from 5.63 to 8.61 mg kg^?1 diet. Data generated during this study would be useful in formulating thiamin‐ and pyridoxine‐balanced feeds for the intensive culture of this fish.     

A Minchinia mercenariae‐like parasite infects cockles Cerastoderma edule in Galicia (NW Spain)

The cockle Cerastoderma edule fishery has traditionally been the most important shellfish species in terms of biomass in Galicia (NW Spain). In the course of a survey of the histopathological conditions affecting this species in the Ria of Arousa, a haplosporidan parasite that had not been observed in Galicia was detected in one of the most productive cockle beds of Galicia. Uni‐ and binucleate cells and multinucleate plasmodia were observed in the connective tissue mainly in the digestive area, gills and gonad. The parasite showed low prevalence, and it was not associated with abnormal cockle mortality. Molecular identification showed that this parasite was closely related to the haplosporidan Minchinia mercenariae that had been reported infecting hard clams Mercenaria mercenaria from the Atlantic coast of the United States. The molecular characterization of its SSU rDNA region allowed obtaining a fragment of 1,796 bp showing 98% homology with M. mercenariae parasite. Phylogenetic analysis supported this identification as this parasite was clustered in the same clade as M. mercenariae from the United States and other M. mercenariae‐like sequences from the UK, with bootstrap value of 99%. The occurrence of M. mercenariae‐like parasites infecting molluscs outside the United States is confirmed.     

A novel approach to denitrification processes in a zero-discharge recirculating system for small-scale urban aquaculture

This paper presents an innovative process to solve the nitrate build-up problem in recirculating aquaculture systems (RAS). The novel aspects of the process lie in a denitrification bioreactor system that uses solid cotton wool as the primary carbon source and a unique degassing chamber. In the latter, the water is physically stripped of dissolved gaseous O₂ (by means of a Venturi vacuum tube), and the subsequent denitrification becomes more efficient due to elimination of the problems of oxygen inhibition of denitrification and aerobic consumption of cotton wool. The cotton wool medium also serves as a physical barrier that traps organic particles, which, in turn, act as an additional carbon source for denitrification. Operation in the proposed system gives an extremely low C/N ratio of 0.82 g of cotton wool/g of nitrate N, which contributes to a significant reduction of biofilter volume. The additional advantage of using solid cotton wool as the carbon source is that it does not release organic residuals into the liquid to be recycled. Operation of the system over a long period consistently produced effluents with low nitrate levels (below 10 mg N/l), and there was only a very small need to replace system water. The overall treatment scheme, also incorporating an aerobic nitrification biofilter and a granular filtration device, produced water of excellent quality, i.e., with near-zero levels of nitrite and ammonia, a sufficiently high pH for aquaculture, and low turbidity. The proposed system thus provides a solution for sustainable small-scale, urban aquaculture operation with a very high recovery of water (over 99%) and minimal waste disposal.     

Fertilization by refrigerator stored sperm of the Indian major carp, Labeo calbasu (Hamilton, 1822)

This study reports on the spermatological properties, and on the development of a protocol for refrigerator storage (4°C) of Labeo calbasu (Hamilton, 1822) sperm for artificial breeding. Volume, motility, concentration and pH of the freshly collected sperm were 2.21 ± 0.53 (μL g^?1 of fish weight) (mean ± SD), 95 ± 1 (%), 1.93 ± 0.44 × 10⁹ (cells mL^?1) and 7.56 ± 0.17 respectively. Sperm activation was evaluated at different osmolalities of NaCl solution, and motility ceased completely when osmolality of the extender was ≥287 mOsmol kg^?1. Sperm retained motility for 24, 72 and 108 h, after refrigerator storage when sperm were undiluted, suspended in Alsever's solution and suspended in Alsever's solution containing 5% methanol respectively. Fertilization rate of fresh eggs with sperm stored at 4°C in Alsever's solution and Alsever's solution containing 5% methanol was 77% and 60% with a hatching rate of 60% and 43% respectively. The fertilization and hatching success of the stored sperm suggests potential to use refrigeration for transporting genetic material to hatcheries for artificial breeding of L. calbasu in Bangladesh.     

Effects of metomidate anaesthesia or transfer to pur sea water on plasma parameters in ammonia-exposed Atlantic salmon (Salmo salar L) in sea water

Atlantic salmon (Salmo salar L) postsmolts weighing 150 ± 53 g were exposed to 14–15 mg l^–1 TA-N (total ammonia-N) in sea water in 1 m³ tanks for 24h. Blood samples were then taken A) immediately after the fish were netted from the exposure tanks and stunned by a blow to the head; B) 2–20 min after the fish were transferred to 15 l of an anaesthetic solution of metomidate in ammonia-free sea water; or C) 2–20 min after the fish were transferred to 15 l of ammonia-free sea water. Plasma TA-N level was 18% lower in the anaesthetised fish compared to in the fish sampled directly from the exposure tanks (p 0.05), and accordingly 16% lower in the fish transferred to pure sea water although this difference was not significant (p = 0.07). Plasma glucose level was higher in the fish transferred to pure sea water than in the fish receiving the two other treatments (p 0.05), but plasma urea, osmolality, Na^{+, Cl–, Ca2+ or Mg2+} levels did not vary significantly between the different treatments. Plasma TA-N level increased with time in the fish in the metomidate solution (p 0.02).