转基因鱼试验湖浮游生物群落DNA指纹与理化因子的关系

对转基因鱼试验湖7个采样点的浮游生物群落进行了PCR-DGGE指纹分析,并进而探讨了DNA指纹与理化因子的关系.结果表明:(1)PCB-DGGE指纹图谱中共含104谱带,其中原核谱带58条,真核谱带46条,其多态性位点分别为87.9%和82.6%.(2)各站点的理化因子中,Ⅰ站的TP含量最高(0.10 mg/L),TN含量在Ⅲ站最高(0.34 mg/L),且各站点波动较大,Ⅴ站的透明度最低(63.00 cm);NO3-N、NH4-N、pH、DO、COD及电导率在各站点变化不大.基于原核生物图谱的相似性聚类分析表明,浮游生物群落Ⅵ和Ⅶ、Ⅳ和Ⅴ、Ⅱ和Ⅲ相似度分别较高,Ⅰ站有别于其它各站,单独为1枝;基于真核生物图谱的聚类分析显示,Ⅰ、Ⅱ站聚为1枝,Ⅳ、Ⅴ、Ⅵ和Ⅶ依次相聚后与Ⅲ站聚为另1大枝,Ⅰ、Ⅱ站与Ⅲ站相距较近;理化因子的主成分分析结果与之基本吻合.因此,浮游生物群落DNA多态性与环境理化因子是密切相关的,这类资料的积累将为在分子水平上建立水质预测预报体系奠定基础,为评价转基因鱼生态安全性提供依据.     

鲇鱼线粒体DNA的酶切图谱

采用差速离心法及ＤＮａｓｅⅠ、ＲＮａｓｅ消化法制备并纯化了鲇（Ｓｉｌｕｒｕｓａｓｏｔｕｓ）肝脏线粒体ＤＮＡ（ｍｉｔｏｃｈｏｎｄｒｉａｌＤＮＡ，ｍｔＤＮＡ）。用８种限制性内切酶对ｍｔＤＮＡ进行了分析。ＢｇⅡ、ＥｃｏｒⅠ、ＰｓｔⅠ、ＢｇｌⅠ、ＢａｍＨⅠ、ＸｂａⅠ、ＨｉｎｄⅢ、ＸｈｏⅠ在鲇ｍｔＤＮＡ分子上分别具１、１、１、２、２、７、７和０个切点。ｍｔＤＮＡ分子量约１０．８４×１０￣６道尔顿，大小为１７．５４ｋｉｌｏｂａｓｅｐａｉｒｓ。根据单酶和双酶解片段的数目和分子量，建立了鲇ｍｔＤＮＡ的限制性酶切图谱。     

大连市甘井子区北部沿海浮筏养殖水环境的初步观测

本文以１９９５年８～９月“太平洋牡蛎病害防治技术”的水环境调查资料为基础，初步分析了甘井子区北部沿海，在夏季高温期水体中理化要素（Ｔ、Ｓ、ＤＯ、ＣＯＤ、透明度），营养盐（ＮＨ３－Ｎ，ＮＯ２－Ｎ，ＮＯ３－Ｎ，ＰＯ４－Ｐ），及浮游生物量（叶绿量ａ）的含量和分布特征，介绍了各要素含量基本处于海水海水正常浓度水平，属于一类海水水质，海区营养水平为中等营养水平，是适宜的浮筏养殖区，但养殖规模应用有所限制。     

光合细菌在盐碱地池塘改良水质的研究

研究了光合细菌（ＰＳＢ）在低洼盐碱地池塘围隔中对水化因子和浮游生物的影响。结果表明：ＰＳＢ的施用对水化因子有较大的影响，其中水体中ＤＯ、ＮＯ３－－Ｎ升高，而ＮＨ４－Ｎ、ＮＯ２－－Ｎ、和ＣＯＤ降低，而对ＰＯ４３－－Ｐ影响不明显。当ＰＳＢ浓度高时，可提高水体的ｐＨ值；对浮游生物无明显影响；ＰＳＢ的一次施用量为１０ｐｐｍ，一次效用时间为６天左右，因而ＰＳＢ可达到改良水质，进而改善水质的目的，尤其在水质恶化时，其作用更显重要。     

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。     

固定化光合细菌净化养鱼水质试验↑（*）

净化模拟养殖水质试验表明，固定化光合细菌可显著提高ＮＨ＋４ － Ｎ 和ＣＯＤ 的去除率，并能增加溶解氧。经１ 个月的鱼种饲养试验，固定化光合细菌（ Ⅲ组） 和游离光合细菌（ Ⅱ组） 鱼体重显著大于对照（ Ⅰ组） ，成活率也高于Ⅰ组。Ⅲ组效果最佳，不仅鱼体质好，活泼，个体较大且整齐，而且体色鲜艳。从水质分析结果看，Ⅲ组明显优于其它各组。     

鱼类细菌群落中的致病嗜水气单胞菌

鱼类细菌群落中的致病嗜水气单胞菌汤伏生，曾勇，张兴忠（中国水产科学院长江水产研究所．沙市４３４０００）朱晓燕（湖北农学院水产系，荆州４３４１０３）关键词鱼类，细菌群落，嗜水气单胞菌，致病性ＰＡＴＨＯＧＥＮＩＣＡＥＲＯＭＯＮＡＳＨＹＤＲＯＰＨＩＬＡＩＮ...     

INGESTIONANDEXCRETIONOFSEVERALANTIBACTERIALDRUGSBYTHEBRINESHRIMP（ARTEMIAPARTHENOGENETICA）1．TOXICITYT

ＩＮＧＥＳＴＩＯＮＡＮＤＥＸＣＲＥＴＩＯＮＯＦＳＥＶＥＲＡＬＡＮＴＩＢＡＣＴＥＲＩＡＬＤＲＵＧＳＢＹＴＨＥＢＲＩＮＥＳＨＲＩＭＰ（ＡＲＴＥＭＩＡＰＡＲＴＨＥＮＯＧＥＮＥＴＩＣＡ）１．ＴＯＸＩＣＩＴＹＴＯＡＲＴＥＭＩＡ，ＩＮＧＥＳＴＩＯＮＡＮＤＥＸＣＲ...     

邛海浮游生物初步研究

邛海浮游生物初步研究姚维志，周仰璟（西南农业大学，重庆６３０７１６）冯锦光，张永忠，何绍鹏，周锡宗，唐俊（西昌市蔬菜水产办公室，６１５０００）关键词邛海，浮游植物，浮游动物ＡＰＲＥＬＩＭＩＮＡＲＹＳＴＵＤＹＯＮＴＨＥＰＬＡＮＫＴＯＮＩＮＱＩＯＮＧＨＡ...     

GPS和GLONASS兼容性研究进展

ＧＰＳ和ＧＬＯＮＡＳＳ兼容性研究进展蒋志凯（大连水产学院．１１６０２４）关键词卫星导航，ＧＰＳ，ＧＬＯＮＡＳＳＡＤＶＡＮＣＥＳＩＮＴＨＥＳＴＵＤＹＯＦＴＨＥＣＯＭＰＡＴＩＢＩＬＩＴＹＯＦＧＰＳＡＮＤＧＬＯＮＡＳＳ￥ＪｉａｎｇＺｈｉｋａｉ（Ｄａｌｉａｎ...     

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.     

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.     

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.     

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.     

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.     

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).