澳洲宝石斑的亲鱼培育技术

介绍澳洲宝石斑的生物学特性和亲鱼培育的管理技术。重点介绍日常管理中要特别注意的问题和疾病防治方法。其中水温能否维持在其最佳繁殖水温(23℃)是亲鱼能否快速性成熟的关键。     

宝石斑鱼的形态特征

通过解剖活体宝石斑鱼 30尾 ,观察并记述了其形态特征和内部器官结构。宝石斑鱼具代表性的特征是体躯厚而扁圆 ,鱼体呈纺锤形 ,头背部眼后微凹 ,体高约为体长的 1/2。上下颌具一行排列细密的尖齿 ,后鼻孔呈横向短裂孔。背鳍鳍棘部与鳍条部相联 ,中间无缺刻 ,生有 14枚棘。鱼体上半部淡蓝绿色 ,腹部色白 ,鱼体两侧不规则的布有近圆形的大斑块及小斑块。胃发达呈“Y”型 ,幽门盲囊 2 0～ 2 4个 (有的末端具分叉 ) ,肠管长 ,为体长的 3～ 3 5倍。胆囊长棒卵形 ,生殖腺细长紧贴于鳔腹面。雌雄异体     

宝石斑鱼养殖试验

20 0 2年 7月份我们从澳大利亚引进宝石斑鱼苗 ,进行了养殖试验。对鱼苗运输、鱼苗暂养、鱼种培育以及越冬养成等环节试验情况进行总结 ,介绍各环节所采取的技术关键以及今后养殖、推广该品种应注意的事项     

宝石鲈工厂化养殖试验

从澳大利亚引进体长3～5cm的鱼苗5000尾,利用地热水控制水温,投喂人工配合饲料,经过12个月养殖后,鱼体均重达到754g。     

温度和盐度对宝石鲈胚胎发育的影响

宝石鲈(Scortum barcoo)是原产于澳大利亚的一种杂食性、中型经济淡水鱼类,对饵料要求不高,生长速度较快,肌肉的Omega-3不饱和脂肪酸含量很高,具有较高的食用价值。2001年首次被引进中国,2004年人工繁殖获得成功。为了让人们充分了解该物种的繁殖生物学特性,同时为宝石鲈的开发利用提供基本数据,本研究对宝石鲈的胚胎发育时序及不同水温和盐度对胚胎发育的影响做了较为祥细的观察与研究。采用人工催产、授精获得受精卵,在水温(27.0±0.5)℃孵化,观察胚胎发育情况。成熟卵圆形、透明、漂浮性,卵径0.87~0.92 mm,吸水后卵膜膨胀直径为2.10 mm左右;胚胎明显特征是有一个直径为0.50 mm左右的大油球。出膜仔鱼全长2.00 mm左右,出膜4 d后卵黄完全吸收,并开始摄食,此时仔鱼全长3.5~3.7 mm。胚胎发育的最低和最高临界水温分别是21℃和31℃,最适水温范围是24~27℃,胚胎发育所需时间与水温成负相关关系。胚胎发育的最适盐度范围为0~8,盐度8时,各个发育时期的胚胎和仔鱼的存活率最高,12为临界盐度。因此在生产实践中要掌握好温度和盐度,以获得最佳的种苗生产效果。     

Schizochytrium as a replacement for fish oil in a fishmeal free diet for jade perch,Scortum barcoo (McCulloch & Waite)

A 10‐week trial was conducted to determine the response of juvenile jade perch Scortum barcoo on the replacement of dietary fish oil (FO) in a fishmeal free diet. Three iso‐nitrogenous, isocaloric and isolipidic diets were formulated, each containing a different primary fat source: FO, linseed oil (LO), and a mixture of Schizochytrium and LO. The substitution of FO with the mixture of Schizochytrium and LO did not cause a difference in growth. However, there was an 8% reduction in weight gain in fish fed dietary LO, indicating that juvenile jade perch do require a minimal concentration of dietary n‐3 highly unsaturated fatty acids (HUFA). Fish fed the Schizochytrium diet stored more efficient n‐3 HUFA and in particular DHA in their flesh, and retained a higher fillet recovery compared to fish fed FO. In addition, we demonstrated that jade perch are able to produce both n‐3 HUFA and n‐6 HUFA when dietary PUFA are present. Fish fed the LO diet for 10 weeks contained the lowest amount of n‐3 HUFA in fillets among dietary treatment groups. However, feeding these fish the Schizochytrium diet for an additional 4 weeks increased the n‐3 HUFA content towards the same concentration of n‐3 HUFA found in the flesh of fish fed FO, without affecting the sensory properties of the fillets. In contrary, feeding the Schizochytrium diet for a continuous period of 14 weeks lowered overall sensory property scores.     

不同盐度下宝石鲈生长性能研究

在0~2.5%范围内设置6个盐度组饲养宝石鲈,温度控制在(26±2)℃,饲养150d后比较其生长性能。试验结果经统计分析表明,不同盐度显著地影响宝石鲈的生长(p<0.05)。在盐度1.0%的水体中,宝石鲈生长速度最快,存活率高,饲料系数较低。综合结果认为宝石鲈的最适生长盐度为1.0%左右,可望推广到盐碱水体或海水地区养殖。     

宝石斑常见寄生虫病的防治

宝石斑(Scortum barcoo)属鲈形目,鯻科、革鯻属,学名高体革鯻,原产于澳大利亚。我国于2001年6月下旬首次引进10万尾苗种,2002年夏再次批量引进苗种,并分别进行池塘养殖和水库网箱养殖,在一定规模的生产性试养中取得了阶段性成果。随着宝石斑养殖的不断扩展,集约化养殖规模的扩大,出现了一些寄生虫病害,经反复试验,总结出有效的控制方法。一、白点病1.病原:多子小瓜虫Ichthyophthirius multifiliis。2.寄生部位:皮肤、鳃、鳍、口腔、眼眶等部位出现白色点状囊泡。3.症状:凡有虫体寄生的部位,肉眼可见囊泡状小白点,严重时白点随处可见。小瓜…     

高体革鯻鱼病的防治

高体革鯻(Scortumbarcoo)是澳大利亚特有的淡水鱼类,属鲈形目、鯻科、革鯻属,我国于2001年引进并开始养殖。由于高体革鯻引入我国试养只有3年多,故鱼病不会很多,笔者在其引养过程中发现存在4种鱼病,现将防治方法报道如下。一、肝肾综合症此病为营养性疾病,若无并发症则一般不会传染。病鱼体色发黑,腹部稍大,无腹水,有些病鱼会失去平衡或仰卧。病鱼肝脏土黄色,水肿,边缘不齐,肝细胞之间有脂滴;胆肿大,墨绿色,胆汁有时外溢;肾紫黑色,前肾肿胀,易触破;消化管内常有大量液体,有时肠管稍充血;腹腔内脂肪块重量高达体重的11.9%(10.1%~14.1%)。治…     

宝石斑常见疾病的防治

一、指环虫病Dactylogyrosis1.病原:指环虫Dactylogy SP.。2.寄生危害部位:鳃、皮肤。从2001年夏引进宝石斑原种饲养至今,仅在鱼病预防检疫时,于集约化养殖的水泥池中发现一例,并于鳃上检视到虫体,迄今再没有出现。3.症状:鱼体消瘦,体色变黑,鳃瓣处浮肿,局部糜烂,呈苍白色,严重时鳃丝局部坏死,溃烂。虫体寄生在体表时,表现为鳍膜破裂,鳃丝损伤,皮肤溃疡。镜检时每个视野有10个虫体,或将鳃瓣置于有清水的培养皿中持放大镜在亮光处细看,鳃丝间有白色的蠕动虫体,若每个鳃瓣有50个以上的虫体即可确诊。4.流行情况:指环虫病在我国淡水鱼类养殖…     

宝石鲈鱼种繁育与养殖技术

宝石鲈学名高体革鯻（Scortum Barcoo）,又称宝石斑、佳帝鱼,分类上为鲈形目,鯻科,革鯻属,原产于澳大利亚格拉斯顿巴库河（Gladston’s Barcoo）上游至昆士兰东海岸一带,为澳大利亚一种重要的经济淡水鱼类。宝石鲈肉美味鲜,无肌间刺,含肉率高,且营养丰富。据澳大利亚联邦科学与工业研究组织（CSIRO,1998）的研究报道,宝石鲈鱼体含肉率为58．3％,     

养殖密度对宝石鲈生长性能和血液生化指标的影响

试验对循环水养殖系统中不同养殖密度宝石鲈(50,100,150,220尾/m3)的生长性能及血液生化指标进行比较.结果表明,150尾/m3组宝石鲈的生长较有优势,其特定生长率(1.61%/d)和存活率(89%)均较高,饲料系数较低(1.70);密度对血液中的谷草转氨酶、谷丙转氨酶和胆红素的影响显著(P＜0.05),随养殖密度增加其浓度呈上升趋势,均在220尾/m3密度组上升最多;密度对血清无机离子(钾、钠、氯、镁、磷)也有影响.综合认为循环水养殖条件下,150尾/m3养殖密度组宝石鲈生长效果较具优势.     

宝石斑鱼人工育苗及养成试验

2004年4月引进宝石斑鱼2龄后备亲鱼,2005年6月首次获得性腺发育成熟的亲鱼。2005年6月和2006年6月,4次进行宝石斑鱼人工育苗均获成功,共催产雌亲鱼22尾,获受精卵118万粒,繁育鱼花75万尾。养成试验也取得了喜人的成绩。     

不同强化物质对卤虫体内游离氨基酸含量的影响

以卤虫无节幼体作为试验材料,研究不同强化物质对卤虫体内游离氨基酸(FAA)含量的影响。试验分为4组,分别强化赖氨酸(Lys)、裂壶藻Schizochytrium、赖氨酸加裂壶藻以及空白对照组,试验进行16h,每4h取样1次。结果显示,试验结束时,赖氨酸组的卤虫体内游离Lys含量显著高于其他3个组,且较强化前相比增加了4倍多,裂壶藻组的含量最低。除苏氨酸(Thr)外,赖氨酸组其他游离必需氨基酸以及天冬氨酸(Asp)、丝氨酸(Ser)、甘氨酸(Gly)、酪氨酸(Tyr)含量都显著高于其他3个组。赖氨酸加裂壶藻组,Thr、Ser、Gly、丙氨酸(Ala)、组氨酸(His)和脯氨酸(Pro)含量均有不同程度的减少,其余组的卤虫,只有Thr含量减少,其他几种FAA水平均增加。试验过程中FAA水平随时间的变化趋势,空白组和赖氨酸加裂壶藻组相同,除Thr外,其余FAA含量都是在4h时增高,8h时下降,12h时升高;而在赖氨酸组和裂壶藻组的卤虫体内,这些FAA含量是前8h升高,12h时降低,16h时又升高。     

宝石斑体内蛋白酶和脂肪酶活性的研究

对宝石斑 (Scortumbarcoo)的胃、幽门盲囊、肠道、肝胰脏等九个部位进行了蛋白酶和脂肪酶活性的检测。结果表明 ,宝石斑胃蛋白酶的活性最高 ,其最适 pH值为 2 2～ 3 0 ;幽门盲囊中既有碱性蛋白酶 ,也有酸性蛋白酶 ,以前者为主 ,其最适pH为 8 2～ 8 6。后肠的蛋白酶活性很低 ,肝胰脏和脾脏中检测到极低的蛋白酶活性 ,胆汁中未检测到蛋白酶 ;脂肪酶的活性在肠道的中后段最高 ,其次是幽门盲囊 ,胆囊中的脂肪酶活性稍次于胃 ,肝胰赃和脾脏未检测到脂肪酶。     

宝石鲈耗氧率和窒息点的初步测定

在实验室内对2种规格宝石鲈的耗氧率、耗氧量及窒息点进行了测定。实验用水为曝气24 h以上的自来水,水温 25℃,pH值6.5-7．0,D04．9 mg/L。结果表明:宝石鲈的耗氧率随体重增加而降低,而耗氧量和窒息点随体重的增加而上升。平均体长4．77 cm、体重2．18g/尾的宝石鲈耗氧率为0．2561 mg/g·h,耗氧量0．5654 mg/尾·h,窒息点0．448 mg/L;平均体长6．09 cm、体重4．78 g/尾的宝石鲈耗氧率为0．2473 mg/g·h,耗氧量1．1840 mg/尾·h,窒息点0．632 mg/L。     

Evaluation of vitamin C-enriched Artemia nauplii for larvae of the giant freshwater prawn

The effect of high levels of ascorbic acid (AA) delivered through enriched live food has been verified through the successful culture of larval giant freshwater prawn, Macrobrachium rosenbergii. Two successive feeding trials were set up using a control (550 g AA g^–1 DW) and two different AA-enrichment levels in Artemia (1300 and 2750 g AA g^–1 DW). Under standard culture conditions, no differences in growth nor survival could be observed demonstrating that the nutritional requirements are below 550 g AA g^–1 DW, which is the normal level occurring in freshly-hatched Artemia. However, a significantly positive effect could be demonstrated on the physiological condition of the postlarvae, measured by means of a salinity stress test, when vitamin C-boosted live food was administered. Since the AA levels in the predator larvae are linked with the enrichment levels in the live prey, it may be assumed that a positive influence on stress resistance was caused by feeding vitamin C-enriched Artemia. It is expected that under suboptimal conditions, supplementation of high vitamin C levels might also enhance production characteristics.     

Selection of lactic acid bacteria as candidate probiotics and in vivo test on Artemia nauplii

Lactic acid bacteria (LAB) were isolated from rotifer cultures in a marine hatchery to search for potential probiotics for marine animals. Fifteen strains were first selected among a total of 55, according to antibacterial activity against Vibrio sp. Among eight strains identified as Lactobacillus casei, four were highly adhesive, suggesting some ability for surface colonization. The other strains were identified as Lactobacillus plantarum, Lactobacillus dextrinicus, and Leuconostoc sp. To validate probiotic potential, Artemia were challenged against pathogenic Vibrio alginolyticus, with or without one of six selected LAB strains. The six strains protected Artemia against the pathogen, to some extent on condition that nutrient enrichment was provided. La. casei BR51 and X2 were preferred, as they were efficient even in the absence of nutrient supply. La. casei X2 was finally selected as candidate probiotic, due to the best growth performances of Artemia, with or without the pathogen.     

养殖澳洲宝石鱼迟缓爱德华氏菌的分离鉴定及致病基因的检测

从患病澳洲宝石鱼体内分离到一株致病菌(编号Et4),对该菌的生化特性及致病基因进行检测,并进行了药敏和人工感染实验。结果显示:菌株Et4的生化鉴定结果与迟缓爱德华氏菌(Edwardsiella tarda)标准菌株(AY77513)一致;其16S rRNA序列,经同源性比对与迟缓爱德华氏菌核苷酸相似度最高,达99%;根据迟缓爱德华氏菌的致病基因Ⅲ型分泌系统装置蛋白esaV基因序列设计引物,进行PCR扩增,得到708 bp序列,该序列与迟缓爱德华氏菌的esaV基因序列相似性达99.3%,说明菌株Et4具有esaV基因。菌株Et4对环丙沙星等较敏感,对其它药物中度或不敏感,具有较强的致病力(LD50=3.74×104CFU/mL),从病鱼中可以重新分离出此菌。综合形态学、生化特性、16S rDNA序列及致病基因序列鉴定其为迟缓爱德华氏菌。     

Effect of Streptomyces sp. RL8 on the survival of Artemia franciscana nauplii and resistance to Vibrio parahaemolyticus

Fisheries Science - Artemia franciscana nauplii were enriched with Streptomyces sp. RL8 in order to assess its effect on the survival rate of Artemia and its protective effects against Vibrio...