泉州市牡蛎养殖现状及采苗应注意事项

<正>牡蛎养殖历来是泉州传统的贝类养殖,几年来牡蛎的养殖面积占到海水贝类养殖总面积的70%左右。近年由于海区面积的减少、养殖鲍鱼的盛行,牡蛎养殖面积有所减少。但自三公消费禁令以来,高档水产品滞销,经济海产贝类例如牡蛎、缢蛏等需求有所增加,价格反而上扬。预计往后一段时间牡蛎等经济海产贝类还是养殖户的首选养殖对象。现将近年来泉州市牡蛎养殖情况简要介绍如下,见表1。     

我国养殖贝类大规模死亡的原因分析及防治对策

我国贝类养殖的历史悠久,现代贝类养殖业起源于本世纪六十一七十年代,老一代科学家在极为困难的条件下从事贝类养殖科学的研究,在牡蛎、贻贝、扇贝、珍珠贝等贝类的养殖理论和技术方面取得突破,并最终形成产业。目前,我国已经成为世界上最大的贝类养殖生产国。随着养殖品种的增加、养殖规模的扩大及养殖历史的延长,病害问题也日趋严重,不同种类出现了不同规模的死亡。本文在对我国贝类养殖的基本情况做广泛调查的基础上,就发病规律和死亡原因做初步的分析并对防治方法提出建议。一、我国贝类养殖的主要种类和养殖现状我国养殖的经济…     

预防筏式养殖长牡蛎死亡的主要技术措施

<正>牡蛎在我国水产养殖中占据重要地位,据2016年中国渔业统计年鉴,2015年牡蛎养殖产量为457万吨,占贝类养殖产量的33.67%,海水养殖总产量的24.38%。目前随着互联网和冷链物流的发展,牡蛎是水产品中最合适冬季生吃和活体运输的水产品。随着牡蛎养殖规模的不断扩大,牡蛎的品质却在下降,表现出养殖的长牡蛎出肉率低、形态不规则、大量死亡的问题,特别近年来牡蛎的大量死亡已影响了牡蛎的养殖积极性和产业的发展。为此笔者通过牡蛎养殖现场调查分析,结合     

减少滩涂养殖蛤仔和牡蛎夏季死亡的对策措施

每年夏季发生的滩涂养殖蛤仔和牡蛎大面积死亡,给养殖部门造成了巨大的经济损失,如何减少以效防止死亡受到有关方面的关注。针对这一问题,1995～1997年间,我们承担了由山东科委和中国水产科学研究院共同下达的“生态环境变化对滩涂贝类死亡影响机理的研究”课题。本文根据山东省乳山湾滩涂蛤仔和牡蛎养殖区的生态环境及蛤仔和牡蛎死亡状况调查和死亡环境条件疚模拟试验的结果。提出减少滩涂养殖蛤仔和牡蛎夏季死亡的对策措施,以期在更大范围内,对养殖单位有所借鉴和帮助。1．适度发展科学养殖充分开发利用摊面,扩大养植面积,是一种…     

牡蛎镀膜保鲜技术研究

牡蛎(Ｏｙｓｔｅｒ),亦称蚝、蚵等,属瓣鳃纲(Ｌａｍｅｌｌｉｂｒａｎｃｈｉａ),牡蛎科(Ｏｓｔｒｅｉｄａｅ),广布于热带及亚热带。我国自黄海、渤海至南海均产,以福建、广东、台湾为多。牡蛎是优良的海产养殖贝类,种类甚多,共约百余种。在我国牡蛎主要养殖品种有褶牡蛎(Ｏ.ｐｌｉｃａｔｕｌａ)、近江牡蛎(Ｏ.ｒｉｖｕｌａｒｉｓ)、太平洋牡蛎(ＣｒａｓｓｏｓｔｅｒａｇｉｇａｓＴｈｕｍｂｅｒｇ)、大连湾牡蛎(Ｏ.ｔａｌｉｅｎｗｈａｎｅｎｓｉｓ)及密鳞牡蛎(ＯｓｔｒｅａｄｅｎｓｅｌａｍｏｓａＬｉｓｃｈｋｅ)等[刘家福等1995]。牡蛎肉称蛎…     

重要经济贝类原虫病及其诊断技术研究进展

贝类具有食物链短、定居性强、育苗和养殖基础好、成本相对低等特点,其养殖业已成为我国沿海地区海水养殖的重要支柱产业之一.然而,随着养殖规模的不断扩大,滩涂环境质量受到不同程度的影响.自20世纪90年代起,我国养殖贝类病害日趋严重,沿海养殖的文蛤(Meretrix lusoria)、牡蛎等不断发病,给贝类产业带来严重危害[1].其中由各种原虫引起的原虫病是养殖贝类的主要病害.     

牡蛎的品质及其开发利用

牡蛎是沿海习见且大量生长的一种贝类，属于软体动物门、瓣鳃纲、牡蛎科。我国沿海盛产的牡蛎，主要有近江牡蛎、长牡蛎、褶牡蛎、花缘牡蛎、大连湾牡蛎、密鳞牡蛎等。牡蛎是广东沿海养殖的主要贝类之一，碍石湾、红海湾、深圳湾、唐家湾、镇海湾和海陵湾等地有大量养殖。     

闽南沿海牡蛎、花蛤、缢蛏体内重金属的检测与评价

本文利用1998-1999年福建闽南沿海养殖贝类体的重金属检测资料,分析了3种主要养殖贝类体的重金属含量及分布。结果表明:厦门杏林宝珠屿、马銮湾海域养殖的褶牡蛎体内的重金属含量明显高于其他养殖区。不同养殖区之间养殖贝类的Cu、Pb、Cd、Zn、Hg含量,以及这些元素在各种贝类中都存在较大的差异。文中还根据全国海岸带污染综合调查专业组制定的海洋生物污染评价标准,对养殖贝类的重金属污染程度进行了评价,结果闽南沿海的养殖贝类基本未受重金属污染或污染程度较轻。     

我国贝类HACCP体系有效实施途径的探讨

我国生活着800余种海洋贝类,贝类产量名列世界第一。海水贝类养殖产量占海水养殖总产量的80%,是海水养殖业的一个重要组成部分。养殖品种有牡蛎、贻贝、扇贝、文蛤、青蛤、蛏、蚶、鲍等十多种,是我国水产品出口创汇的重要品种。双壳贝类,例如牡蛎、杂色蛤、毛蚶、文蛤,具有非选     

牡蛎的微生物疾病

牡蛎有着悠久的养殖历史,在我国有2000年以上的养殖史。它是当今世界上贝类养殖的支柱产业之一,各临海国家均有生产,其产量居养殖贝类之首。在我国主要养殖种类有:长牡蛎(太平洋牡蛎,Cras-sostrea gigas)、褶牡蛎(O strea cucullata)、近江牡蛎(O.rivu-laris)、大连湾牡蛎(O.talienwhanensis)、密鳞牡蛎(O.denseanellosa)和僧帽牡蛎(Saccostrea cucullata)等6种。其他国家养殖的品种有:欧洲巨蛎(C.angulata)、商业巨蛎(澳大利亚岩牡蛎C.comm ercialis)、C.gryphoides、C.rhizopho-rae、美洲巨蛎(C.virginica、O.equestris)、叶片牡蛎(…     

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.     

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.     

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.     

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).