斑点叉尾胚胎及卵黄囊期仔鱼发育的观察

试验对斑点叉尾的胚胎及卵黄囊期仔鱼形态发育的过程进行观察、描述,研究了其发育特征。结果表明：斑点叉尾受精卵在水温24±1℃时,出膜时间（胚胎期）约为147h 30min。水温25±1℃时,斑点叉尾鮰卵黄囊期约为134h。     

斑点叉尾鮰胚胎和幼苗发育的观察

斑点叉尾鮰卵为圆球形、桔黄色，属于沉性，透明并具有粘性，卵与卵之间的粘性较强，产出时互相粘合成不规则的块状。卵的平均直径为3．457mm，受精卵在水温25．5—29℃时，出膜时间为146小时56分钟(6天以上)。孵化出膜的仔鱼呈金黄色，卵黄桃红色，体较透明，体全长7．89—8．13mm，平均为7．95mm。出膜4天后，开始摄食，转入混合营养阶段，10天左右器官分化完善。出膜后仔鱼集群堆积于水体底部。眼晶体、黑色素和嗅囊出现，心脏形成和搏动，内耳、尾和胸鳍原基形成，开始血液循环及红色素，鳃弓、鳃丝和鳃盖原基形成，消化道、肛门和肝脏等均在出膜之前形成。     

斑点叉尾鮰人工繁殖实验

我们于1989年开始进行斑点叉尾鮰的人工繁殖试验研究，现将试验情况报告如下。     

红色和黑色斑点叉尾鮰人工繁殖试验

通过人工控制手段,促使红色斑点叉尾鮰与黑色斑点叉尾鮰自行配对、产卵、收集受精卵集中孵化,获得浅黑色的鱼苗;要获得稳定的红鮰鱼苗,必须采取红色斑点叉尾鮰自交的方法。     

广西地区斑点叉尾鮰人工繁殖试验

从池塘养殖的成鱼中选择亲鱼，培育至3龄以上，自然受精、人工孵化。4月上旬获第1批受精卵，经4d室内孵化。出苗36万尾，培育至7～8cm 32．4万尾，成活率达90％。比湖北地区产苗时间提前1个多月。     

斑点叉尾鮰de生殖特性及人工繁殖技术

斑点叉尾鮰是近20年来从国外引进的淡水养殖鱼类。由于其初始性成熟年龄较大，繁殖力偏低，制约了苗种的规模化生产，造成苗种供应紧张。笔者自1997年以来观察了该鱼的生殖特性，并进行了人工繁殖试验，累计催产亲鱼1050组，共获苗500多万尾。     

斑点叉尾鮰病毒性疾病综述

综述了斑点叉尾鮰病毒病的流行情况、临床症状,论述了影响疾病爆发的因子、诊断、治疗、控制和预防措施。     

斑点叉尾鮰亲鱼的运输

2000年3月30日,将美国密西西比品系原种斑点叉尾鮰(Ictalurus punctalus)亲鱼,自湖北荆州张家山渔场运往辽宁铁岭三家子渔场.起运亲鱼698尾共1 087kg,经20 h到达目的地,成活率97.9%.     

斑点叉尾鮰的人工繁殖技术

阐述了斑点叉尾的人工繁殖技术，其中包括亲鱼池的条件、亲鱼的选择与培育、亲鱼的产卵以及鱼卵的孵化。     

斑点叉尾鮰大规格鱼种培育技术

使用面积2668m^2的池塘进行斑点叉尾鮰大规格鱼种培育试验，通过合理投喂、采取有效的水质调控和疾病控制，结果共收获斑点叉尾鮰大规格鱼种1090．6kg，平均规格41．5g／尾，成活率为87．6％，平均每667m^2利润为1680．5元。     

斑点叉尾鮰全基因组微卫星分布特征分析

为了解斑点叉尾鮰(Ictalurus punctatus)全基因组中完整型微卫星的分布特征,本研究使用生物信息学软件MISA对其全基因组微卫星进行了搜索并分析。结果显示,在斑点叉尾鮰29条染色体中,筛选到完整型微卫星共510 256个,总长度达11 036 941 bp。其中,微卫星数量最多的是2号染色体(25 284个),其次分别是3号、1号和5号染色体,29号染色体的微卫星数量最少,只有11 591个。每条染色体长度与位于其上的微卫星的数量均显著相关(SPSS, r=0.98, P<0.01)。27号染色体的微卫星相对丰度最大(785.03个/Mb),11号染色体的微卫星相对丰度最小(615.89个/Mb)。6种重复拷贝类型的微卫星中,单碱基的数量最多,占总数的45.31%,随后依次是二碱基(38.53%)、三碱基(8.73%)、四碱基(6.93%)、五碱基(0.46%)和六碱基(0.04%)。斑点叉尾鮰全基因组微卫星中,前10种优势重复拷贝类别为A、AC、AG、AT、AAT、AAAT、C、AAC、AAAC和AAG,表现出明显的A、T碱基优势。本研究结果可为进一步研究斑点叉尾鮰全基因组特征提供参考,并为今后进行斑点叉尾鮰分子标记辅助育种及遗传信息评估等工作提供基础资料。     

外源核苷酸对斑点叉尾(鱼回)生长及肠道组织发育的影响

以斑点叉尾(鱼回)幼鱼为试验对象,研究不同水平外源核苷酸对其生长和肠道发育的影响.在基础饲料中分别添加0.0%(对照组)、0.02%、0.05%和0.1%的外源核苷酸.结果表明,在斑点叉尾(鱼回)幼鱼日粮中添加外源核苷酸,促生长作用不显著(P>0.05),但可显著促进肠道组织的发育(P<0.05).     

Low-Quality Diets for Growout of Channel Catfish,Ictalurus punctatus

Abstract

A feeding trial was conducted to evaluate low-quality diets for growout of pond-raised channel catfish. Five practical diets containing various levels of protein (10-28%) of varying quality (with or without animal protein and/or soybean meal), and with or without certain nutrient supplements (vitamin, minerals, lysine, or fat) were fed to channel catfish, Ictalurus punctatusstocked in 0.04-ha earthen ponds at a rate of 17,290 fish/ha. The diets were as follows: (1) 28% protein, nutritionally complete control; (2) 28% protein without supplemental vitamins, minerals, or fat; (3) 18% protein + supplemental lysine, vitamins, and minerals, but without animal protein; (4) 10% protein without animal protein, soybean meal, or supplemental vitamins and minerals; and (5) 10% protein + supplemental lysine, vitamins, and minerals, but without animal protein or soybean meal. Each diet was fed once daily to apparent satiation to fish in five replicate ponds for a single growing season. Fish fed diets containing 18% or 28% protein without supplements had similar diet consumption rates and weight gain as those fed the 28% control diet, but the fish fed the control diet converted diet more efficiently. Fish fed the 10% protein diet without supplements consumed less diet, converted diet less efficiently, and gained less weight than fish fed diets containing higher levels of protein. The addition of supplements to the 10% protein diet increased weight gain and processing yield as compared to fish fed the 10% protein diet without supplements. Body fattiness increased, fillet protein decreased, and carcass, fillet and nugget yields decreased as dietary protein decreased. The data show that pond-raised channel catfish can be grown effectively on a diet containing 18% protein that is of relatively low quality, but fattiness is increased and processing yield is decreased. However, because of the negative aspects of this diet, we would not recommend it for general use in commercial catfish culture. It could be used where fattiness and processing yield are not of consequence, such as recreational ponds. For that matter, the 10% diet without supplements could be used as well in these situations if maximum growth is not desired.     

利用mtDNA控制区序列分析斑点叉尾(鮰)的遗传多样性

利用m tDNA控制区序列对1984、1997年引进的斑点叉尾鮰群体遗传多态性进行了分析。通过PCR产物测序法,测定了40尾斑点叉尾鮰线粒体DNA的一段包括部分Cytb基因、tRNAThr、tRNAPro、D-loop控制区和部分tRNAThe长度为1256 bp的核苷酸序列,经过比对分析得到7个序列单元型。7个单元型中共有13个碱基转换位点,全部发生在控制区,其序列相似度平均为99.58%。群体总的序列单元型多态性比例为17.5%,其中1997年群体的单元型多态性比例为35%,是1984年群体单元型多态性比例(15.0%)的2倍多。初步表明1984年引进的群体遗传多样性较低。     

斑点叉尾鮰基因组的研究

作为重要的水产养殖种类之一,斑点叉尾(IctalurusPunctatus)的基因组学研究已经取得了较大进展。其众多遗传连锁图以及与表型性状有关的DNA分子标记和基因组资源已经建立;基因组中一些重要的重复片段,已经得到鉴定和辨别,这更有利于对斑点叉尾鮰基因组进行物理学分析;通过基因组学方法,获得了大量基因或全长cDNA序列、以及基因进化和与功能相关基因表达方面的信息。利用细菌人工染色体叠连群技术,创建斑点叉尾鮰基因组物理图谱,开发特定片段分子标记,进行数量性状基因位点(QTLs)分析和高密度基因组绘图。通过比较图谱,可以更有效地进行大范围EST分析和I型分子标记绘图。cDNA微阵列或基因芯片技术的利用,加快新基因发现和鉴定的步伐,为分子标记辅助育种和病害诊断与防治研究奠定了坚实基础。     

斑点叉尾鮰亲鱼池塘培育关键技术的研究

斑点叉尾鮰(Ictalurus punctatus)繁育亲鱼筛选可量参数:体长为头长的3.88~4.17倍、体长为体高的4.59~5.26倍、体长为尾柄长的5.73~6.73倍、体长为尾柄高的11.05~11.95倍、尾柄长为尾柄高的1.78~1.94倍。亲鱼培育产卵池塘适宜面积为0.20~0.53hm2,单位面积池塘内亲鱼承载量为2400~2550kg/hm2,3~6龄亲鱼放养密度为375~450组/hm2。投喂亲鱼饵料以含蛋白质36%人工配合饵料与动物性饲料相结合。亲鱼培育池塘水体昼夜变化的溶氧量为4.0mg/L以上、pH值为6.8~7.6、氨氮小于0.3mg/L、亚硝酸盐为0.01mg/L以下,亲鱼产卵率为80%以上。     

酵母免疫多糖对受免斑点叉尾免疫应答的增强作用

在饲料中添加定量的酵母免疫多糖,投喂注射接种了福尔马林灭活的嗜水气单胞菌(Aeromonas hydrophila)菌苗的斑点叉尾(Ictalurus punctatus),28 d后通过测定供试鱼的增重量、血清中凝集抗体效价、溶菌酶活性、谷丙转氨酶活性(SGPT)、血清总蛋白含量、白细胞吞噬活性以及活菌攻毒后的免疫保护率(RPS),探讨了酵母免疫多糖对受免斑点叉尾免疫应答的增强作用。结果表明,用添加200.0 mg/(kg.d)酵母免疫多糖的饲料投喂受免斑点叉尾,不仅可以使受免斑点叉尾对灭活嗜水气单胞菌的免疫应答水平提高,增强抵抗嗜水气单胞菌人工感染的能力,而且还具有一定的促进生长和改善肝功能的作用。     

酵母免疫多糖对受免斑点叉尾(鮰)免疫应答的增强作用

在饲料中添加定量的酵母免疫多糖,投喂注射接种了福尔马林灭活的嗜水气单胞菌(Aeromonas hydrophila)菌苗的斑点叉尾(鮰)(Ictalurus punctatus),28 d后通过测定供试鱼的增重量、血清中凝集抗体效价、溶菌酶活性、谷丙转氨酶活性(SGPT)、血清总蛋白含量、白细胞吞噬活性以及活菌攻毒后的免疫保护率(RPS),探讨了酵母免疫多糖对受免斑点叉尾(鮰) 免疫应答的增强作用.结果表明,用添加200.0 mg/(kg·d)酵母免疫多糖的饲料投喂受免斑点叉尾(鮰),不仅可以使受免斑点叉尾(鮰) 对灭活嗜水气单胞菌的免疫应答水平提高,增强抵抗嗜水气单胞菌人工感染的能力,而且还具有一定的促进生长和改善肝功能的作用.     

斑点叉尾鮰、团头鲂池塘混养高产试验

在面积为6667m2 的池塘混养、鲂鱼种,搭配鲢、鳙及银鲫。、鲂及银鲫投喂配合颗粒饲料,鲢、鳙不投饵。设置2台3kW增氧机,饲养209d,结果共产鱼6960kg,团头鲂6889 6kg,异育银鲫345kg,鲢、鳙共2137 4kg,平均产量为2 45kg m2,平均成本为11 45元 m2,平均利润为6 48元 m2,投入产出比为1∶1 56。     

Effects of Water Temperature on Sock Grading of Sub-Marketable Channel Catfish,Ictalurus punctatus,in Earthen Ponds

Abstract

The passive sock grading method used by commercial channel catfish, Ictalurus punctatus, farmers to grade and reduce the number of under-sized fish delivered to processing plants was assessed on an experimental scale. The assessment was conducted at the Aquaculture Research Station at the University of Arkansas, Pine Bluff in 0.1-ha earthen ponds. A rectangular holding sock was fabricated with dimensions of 0.9 m in width, 2.4 m in length, and 1.2 m in depth. The mesh size of the sock was 4.4 cm and the mesh material was nylon netting, 0.64 cm in diameter. Seventeen groups of channel catfish, were graded, with group weights ranging from approximately 115 to 370 kilograms. Fish were held in the sock for approximately three hours (±0.27 hours). The water temperature during the trials ranged from 7.3°C to 28.7°C. The percent removal of fish less than 0.45 kg during the three-hour holding period ranged from 27.6% to 73.3%. Overall, sock grading efficiency increased with increasing water temperature and at water temperatures above 15°C a greater percentage of fish less than 0.45 kg were not retained in the socks.