海水鱼苗池塘繁育技术

近几年来,海水鱼苗人工育苗技术日趋成熟,从室内工厂化育苗模式向室外池塘人工育苗转变。现将这几年在我县佛昙镇一口40亩池塘从事白星笛鲷、斜带髭鲷人工育苗的做法总结如下:一、育苗前的准备1.池塘清池消毒池塘先干塘曝晒15～20天,至底质龟裂。环沟的淤泥要清除,每亩用漂白粉     

海水网箱养殖鱼类刺激隐核虫病的诊断及防治

近年来,海水鱼类网箱养殖的集约化程度不断提高,刺激隐核虫病是海水鱼养殖中危害最大的寄生虫性疾病,又被渔民称为海水鱼白点病。目前,刺激隐核虫病尚不属于国家规定的水生动物疫病和人鱼共患疾病,但因其传染性较强,可感染尖吻鲈、紫红笛鲷、东方鲀、大黄鱼、美国红鱼、鲈鱼、金鲳、石斑鱼、蓝子鱼、白胡椒鲷、真鲷、黑     

我国海水鱼类养殖的现状、问题与对策（下）

二、问题和对策１．突破种苗瓶颈如上所述，有些海水养殖鱼类，其人工培育的种苗已能满足养殖生产需求，但还有相当一部分养殖鱼类，其人工繁殖和育苗技术尚未完全突破，所培育出的种苗数量有限，养殖上所需的种苗大部分从自然海区捕获，有些种类的种苗还需从国外或境外引进。广东养殖的红鳍笛鲷、石斑鱼类、尖吻鲈和花尾胡椒鲷等的种苗自给率为１０％，海区苗占４０％，５０％从泰国和我国台湾等地引进。自然海区每年种苗数量的丰歉受各种因素的制约，很难保证养殖生产有足够的种苗。养殖种苗得不到解决是发展我国海水鱼类养殖的瓶颈之一。…     

红笛鲷和卵形鲳鳗鳃的扫描电镜观察与功能探讨

对两种鲈形目鱼类红笛鲷Lutjanus erythopterus和卵形鲳碜Trachinotus ovatus的鳃结构进行扫描电镜观察。结果表明，红笛鲷和卵形鲳够鳃的表面结构和微细结构与其他硬骨鱼类基本相似，鳃丝表面都具有规则或不规则分布的环形微嵴、沟、坑、孔等结构。红笛鲷的中部鳃丝表面一部分较为平坦，基部鳃丝表面则凹凸不平。红笛鲷的鳃小片高度要较卵形鲳够鳃小片高。红笛鲷和卵形鲳够鳃上皮的几种细胞的形态结构及数量分布存在细微的差异。红笛鲷鳃上的扁平上皮细胞界限清楚，而卵形鲳够鳃上扁平上皮细胞表面遍布不规则的微嵴，细胞界限模糊。红笛鲷鳃丝表面的氯细胞数量多于卵形鲳够，这可能与两种鱼对生活环境、生活习性的长期演变相关。     

红笛鲷和卵形鲳鲹鳃的扫描电镜观察与功能探讨

对两种鲈形目鱼类红笛鲷Lutjanus erythopterus和卵形鲳(鱼参) Trachinotus ovatus的鳃结构进行扫描电镜观察。结果表明,红笛鲷和卵形鲳(鱼参)鳃的表面结构和微细结构与其他硬骨鱼类基本相似,鳃丝表面都具有规则或不规则分布的环形微嵴、沟、坑、孔等结构。红笛鲷的中部鳃丝表面一部分较为平坦,基部鳃丝表面则凹凸不平。红笛鲷的鳃小片高度要较卵形鲳(鱼参)鳃小片高。红笛鲷和卵形鲳(鱼参)鳃上皮的几种细胞的形态结构及数量分布存在细微的差异。红笛鲷鳃上的扁平上皮细胞界限清楚,而卵形鲳(鱼参)鳃上扁平上皮细胞表面遍布不规则的微嵴,细胞界限模糊。红笛鲷鳃丝表面的氯细胞数量多于卵形鲳(鱼参),这可能与两种鱼对生活环境、生活习性的长期演变相关。     

杂交笛鲷人工繁育技术的初步研究

红鳍笛鲷(♀,40尾)×千年笛鲷(♂,45尾)杂交,得到受精卵2.2kg,浮卵率为78.57%,受精卵的孵化率为90.51%,共得到健康仔鱼349.2万尾;千年笛鲷(♀,30尾)×红鳍笛鲷(♂,28尾)的杂交,不成功。在水温27.5~33.5℃、盐度27.5~32.5、pH7.6~8.3、溶解氧4~6 mg/L条件下,杂交笛鲷仔鱼经过32 d的培育,用3个育苗池塘(面积共0.933 hm2)培育出平均全长36.8 mm的幼鱼44.4万尾,单位面积培育鱼种47.57万尾/hm2,育苗成活率为8.95%。     

咸淡水池塘鱼类健康养殖的实用配套技术

我市咸淡水池塘养殖业，经十几年的开拓发展，面积已近 2万亩，养殖品种有鲻、尖吻鲈、花鲈、紫红笛鲷、卵形鲳、红拟石首鱼、黄鳍鲷、细鳞鱼刺、黄斑兰子鱼、金钱鱼和中华乌塘鳢等。 1999年 8月，我站接受由全国水产技术推广总站主持，广东省水产技术推广总站承担的农业部重点水产技术推广和开发项目──“咸淡水池塘鱼类健康养殖技术”推广，应用总面积为 6120亩，单产量 678.6公斤 /亩，亩纯利润 4040元。现将配套的实用技术介绍如下： 　　一、池塘及整治 　　咸淡水池塘鱼类养殖，饲料投料量大，容易累积淤泥。池塘使用期为 5～ 7年…     

广盐性鱼类健康养殖新技术

我国的广盐性鱼类养殖真正始于 2 0世纪 80年代 ,首先在珠江三角洲的东莞、番禺、珠海、深圳等市 ,依托在珠江口两岸围垦起来的咸淡水池塘而兴起。养殖品种开始是传统养殖的鲻、鱼 ,到2 0世纪 80年代初期 ,在珠江口两岸咸淡水池塘放养草鱼、罗非鱼 ,养成的草鱼体色泛黄 ,被称为“金鲩” ,出口港澳 ,很受欢迎。到 80年代中期 ,又进口尖吻鲈苗 ,以及当地捕捞花鲈苗 ,加上人工繁殖加州鲈苗放养 ,号称河口池塘养“三鲈” ,风靡一时。到 80年代后期以来 ,又陆续增加黄鳍鲷、平鲷、灰裸顶鲷、紫红笛鲷、卵形鲳、红拟石首鱼、金钱鱼、细鳞、…     

浙江舟山市条石鲷人工育苗取得新突破

由舟山市海洋与渔业局和舟山市科技局共同立项的“条石鲷人工繁育技术研究”项目在嵊泗县金平水产育苗厂首次获得突破，并通过了来自上海、浙江两省水产专家的现场验收，经验收组抽样计数和测量，4个育苗池分三批共育出健康条石鲷苗31．9万尾，第一批鱼苗平均体长33毫米，第二批鱼苗平均体长20毫米，第三批鱼苗平均体长10．1毫米。     

河口近岸鮨、鲷鱼类池养技术研究

鮨、鲷鱼类种类繁多，国内外记载适宜于咸淡水池塘养殖的品种有鮨科中的尖吻鲈(Lares calcarifer)和花鲈(Lateolabrax japonions)，鲷科中的黄鳍鲷(Sparus latus)、灰鳍鲷(S．berda)和平鲷(Rbabdosargusus surba)。尖吻鲈是亚洲和太平洋热带、亚热带地区重要的经济鱼类，     

湛江港区底泥悬浮物对2种海洋动物的致死效应研究

为评价湛江沿海涉海工程建设过程中引起的悬浮物质对附近海区海洋动物的影响,研究了底泥液相及不同浓度底泥悬浮物对川纹笛鲷和尖吻鲈的致死效应。试验结果表明,在8d的试验时间里,底泥水相对川纹笛鲷和尖吻鲈均无致死效应。底泥悬浮物浓度≤160mg/L时,川纹笛鲷和尖吻鲈的死亡率均处于较低水平。底泥悬浮物浓度≥2560 mg/L时,川纹笛鲷死亡率达75%,尖吻鲈死亡率达70%。通过概率单位法计算得出川纹笛鲷的8d半致死浓度为716.14 mg/L,尖吻鲈的8d半致死浓度为1105.096 mg/L。     

美国红鱼池塘养殖技术

将10000尾10-15cm的大规格美国红鱼苗种，5月初放入盐度25-30，面积1.33hm^2的海水池塘中养殖，放养密度为7500尾/hm^2，饵料采用新鲜小杂鱼，虾。经4个月饲养，当年达到平均全长33.7cm，体重660g的商品规格，成活率达91.4%。饵料系数为4.2，取得了明显经济效益。     

金鲳低盐度养殖试验

利用2．4hm~2低产虾塘改造后试养金鲳,池水盐度5～12。投放2．5～3cm淡化金鲳苗和淡化的1．5cm斑节对虾苗及5～6cm鲻鱼苗。经近6个月养殖,共收获规格400～450g金鲳15185kg,斑节对虾1322kg,鲻2100kg,总产值58万元,纯利14．2万元。     

Nodavirus infections in Israeli mariculture

Viral encephalopathy and retinopathy (VER) infections were diagnosed in five fish species: Epinephelus aeneus, Dicentrarchus labrax, Sciaenops ocellatus, Lates calcarifer and Mugil cephalus cultured on both the Red Sea and Mediterranean coasts of Israel during 1998-2002. Spongiform vacuolation of nervous tissue was observed in histological sections of all examined species. With transmission electron microscopy, paracrystalline arrays and pieces of membrane-associated non-enveloped virions measuring approximately 30 nm in diameter were observed in the brain and retina of all species. At the molecular level, the nodavirus was detected by using a primer set that amplified the T4 region of the coat protein gene. When the same set of primers was used to search for VER in an additional fish species, Sparus aurata, it was found to produce non-specific amplicons, giving rise to false-positive results. This problem was overcome by using a different primer set (F1/VR3), designed on a highly conserved region of the virus gene, which amplified a fragment of 254 bp, and confirmed that S. aurata was nodavirus-free. This set was validated on all five species of infected fish, as well as clinically healthy fish. Comparison of the coat protein genes from the Israeli isolated sequences indicated that more than one viral strain was involved. No strict host-specificity was evident. Red Sea and Mediterranean isolated sequences grouped in distinct clusters, together with several foreign isolates from the Mediterranean area and the Far East, as phylogenetically close to the Epinephelus akaara RGNNV type.     

Commercial marine fish farming in Singapore

Commercial marine fish farming in Singapore is mainly the culture of economically important foodfish species in floating cage nets. There are 84 licensed fish farms occupying 46.5 hectares (ha) of coastal waters. Production from these farms accounts for the bulk of aquaculture production in Singapore, being 3554 tonnes (‘metric tons’, t) in 1995, or 98% of total production of 3625t. The commonly cultured species are the green mussels, Perna viridis L., which form the bulk of production (70.4%), finfish like the groupers, Epinephelus tauvina Forsskal and E. malabaricus Schneider, Asian sea bass, Lates cakarifer Bloch, and snappers, Lutjanus johni Bloch and L. argentimaculatus Forsskal, and crustaceans like the mangrove crab, Scylla serrata Forsskal and spiny lobster, Panilurus polyphagus Herbst. The basic farm structure for fish and mussel culture is the floating wooden raft. In finfish farming, polyethylene cage nets are attached to the raft in which popular foodfishes are cultured. The mussel raft is a structure to which polyethylene ropes are attached to collect and grow out green mussels from natural spatfall. Fish seeds for farming are mostly wild-caught. Only the Asian sea bass and the banana shrimp (Penaeus merguiensis de Mann) are produced by commercial hatcheries in Singapore and the region. The fry of pompano (Trachinotus blochii Lacepede, and T. falcatus Klausewitz & Nielsen) are imported from Taiwan. Trash fish is still the main feed used for the farming of finfish and crustaceans like the mangrove crab and lobster because it is cheap and readily available. This paper also reviews the economics of commercial finfish and mussel farming in Singapore today.     

美国红鱼的胃排空率

在实验室内,25℃条件下测定了体长为22.8±2.6cm、体重为237.8±74.2g的美国红鱼的胃排空率,并比较了线性、指数、平方根3种常用数学模型对其排空曲线的拟合程度。统计检验结果表明,3种数学模型都能很好地拟合实验数据,但通过统计学进一步分析发现,不论是用湿重还是用干重表示胃含物时都以线性模型拟合得最好,用湿重表示胃含物时,其模型为Y=92.93-3.33t(R2=0.94,P<0.001);用干重表示胃含物时,其模型为Y=97.00-3.36t(R2=0.91,P<0.001)。实验还得出在该条件下美国红鱼的胃排空率为每小时排出摄入食物量的3%~4%或每小时排出胃内残余食物量的6%~7%。     

卵形鲳!线粒体１６ＳｒＲＮＡ基因全长序列的克隆与分析

根据近源物种线粒体序列的同源比对，在16S rRNA基因上下游保守区域设计一对通用引物。PCR扩增获得特异的DNA片段，经克隆、测序和比对证实该片段包含了卵形鲳鲹线粒体16S rRNA全长序列1725bp。对5个个体分别测序后比对，发现卵形鲳鲹16S rRNA基因在钦州湾种群个体间存在至少7个变异位点，使5个个体分别具有5种不同的单倍型。将卵形鲳鲹和鲹科其它物种的16S rRNA序列进行比，根据比对结果构建的鲳鲹科各物种的系统进化树，支持鲹科下设四个亚科(鲹亚科，鰤亚科，鲳鲹亚科，鰆鲹亚科)的分类系统。综上所述，16S rRNA基因既可用于卵形鲳鲹种群遗传多样性分析，又适用于鲹科鱼类的系统进化分析。     

Eradication of predatory fishes in shrimp farms by utilization of Thai tea seed

The chief predatory fishes found in shrimp culture ponds in Thailand are Tilapia mossambica, Lates calcarifer, Scatophagus argus, Eluetheronema tetradactylum, Goviupterus chuno, Mystus sp., and other gobies. The eradication of predators, mostly fishes, is necessary for good management of any shrimp farm. Tea seed grown in northern Thailand has been used for this purpose. Quantitative analysis of crude saponin in the tea seed was conducted and some biological tests on the toxicity of crude saponin to fish were performed.The effective dosage of crude saponin for the eradication of predatory fishes was 1.1 ppm, but shrimp, crabs, copepoda, rotifers and brine shrimp (Crustacea) all survived this concentration. The lethal time for fishes increased in proportion to their body weight and the salinity of the pond. The toxicity of the saponin weakened with time.