横带髭鲷Hapalogeny mucronatus(Eydoux et Souleyet)白点虫病的防治研究

本文扼要介绍横带髭鲷白点病发病情况与症状、试验结果，并提出发生白点虫病的病因。     

斜带髭鲷室内产卵的研究

本文报道了斜带髭鲷在室内大量自然产卵的试验结果。实验表明:3龄亲鱼采用加强饵料营养,结合使用适当剂量的激素(TRHR-A_2、TRHR-A_3和HCG)进行催熟和催产,亲鱼产卵量大,产卵集中,卵质较好。使用57尾亲鱼(27尾雌鱼,30尾雄鱼),总产卵量6256.5×10~4粒,受精卵4504.5×10~4粒,平均每尾雌鱼产卵231.7×10~4粒,平均受精率66.7％,仔鱼孵化率 79.2％。     

横带髭鲷早期生长发育特征

本文旨在对横带髭鲷(Hapaloyenys mucronatus)早期生活史阶段的生长发育特征进行观察和测量,详细描述胚胎和仔稚幼鱼各发育时期的时间和形态特征.结果 表明,横带髭鲷的受精卵为透明的圆球形浮性卵,卵径(1.32±0.01)mm,多个大小不等的淡黄色油球.胚胎发育经历6个主要阶段:卵裂前期、卵裂期、囊胚期、...     

斜带髭鲷人工繁殖的初步研究

本文报道了1995—1996年斜带髭鲷人工繁殖试验的初步结果。海水网箱培育2周年的斜带髭鲷性腺已成熟,繁殖季节能自然产卵,卵径907—1019μm,在水温24.2—24.6℃、盐度30.5％、pH值8.25的条件下,受精卵经24小时30分钟发育孵出仔鱼,初孵仔鱼全长2.44—2.77mm。     

横带髭鲷精子超微结构及其生理特征

为探究横带髭鲷(Hapalogenys mucronatus)精子形态和生理特性, 以提高人工繁殖的受精率, 利用扫描电子显微镜和透射电子显微镜观察其精子结构, 并设置不同梯度的盐度、pH 和温度, 探讨横带髭鲷精子快速运动时间、寿命与环境因子的关系。结果表明: 横带髭鲷精子由头部、中部和鞭毛3 段组成, 精子头部呈近球形或椭球形, 头部直径为(1.56±0.05) μm, 细胞核中染色质高度浓缩, 核膜紧贴于质膜, 无顶体; 中段主要由袖套腔与中心粒复合体构成; 鞭毛细长有侧鳍, 为典型“9+2”微管结构。横带髭鲷精子的适宜盐度范围为22~28, 盐度为26 时精子寿命达到最大值425 s; 适宜pH 范围为7~10, 在pH 为7 时, 精子活力最强, 精子寿命达到最大值430 s; 适宜温度范围18~26 ℃, 在水温为22 ℃时精子寿命最长, 为427 s。综上所述, 建议横带髭鲷卵子和精子受精时的最佳水环境盐度为24~26、pH 为7~8、温度为20~22 ℃。     

斜带髭鲷室外人工生态系育苗试验

本文系斜带髭鲷鱼苗室外水泥池不同生态系的育苗试验。在育苗前的“养水"期间,1号池接入小球藻、微绿球藻、扁藻、金藻、轮虫、桡足类、枝角类等生物饵料;2号池仅接入小球藻、轮虫生物饵料。在水温19.1-23℃、比重1.019、pH值8.5的条件下。二池鱼苗经100d的培育后,平均全长各为31mm和29mm,平均体重各为0.90g和0.75g,成活率18.5%和10.1%。试验表明:在育苗前期,生物饵料的多样性有利于开口仔鱼的摄食和营养,也利于鱼苗的生长发育和成活率的提高。     

斜带髭鲷和紫红笛鲷早期发育阶段的行为选择

采用实验生态学方法研究斜带髭鲷(Hapaologenys nitens)和紫红笛鲷(Lutianus argentimaculatus)幼鱼早期发育阶段的行为选择,旨在从行为学角度为优化种苗生产管理提供科学依据。结果显示,斜带髭鲷回避红色底质,对黑色底质的选择则是随着生长而逐渐增加,1 cm体长组的隐匿习性最强,为50.67%;2 cm和3 cm组的隐匿率分别为40.67%和35.33%;4 cm组仅25.00%。1 cm组的顶流率为3.35%,4 cm达71.65%。1 cm和2 cm组在1 760~2 210 lx照度下的分布率分别为41.67%和35.00%,在39~59 lx为8.33%和16.67%,4 cm组在38~53 lx的分布率达41.67%,在2 780~2 980 lx仅为8.33%。体长1 cm的紫红笛鲷喜栖息于白色底质,约占总群体的61.00%,随着生长,对黑色底质的喜好明显增强;4 cm组对白色底质无选择,而对黑色底质的选择达到63.67%。1 cm组的隐匿百分率为55.67%,4 cm组仅为25.00%。在流速1 cm/s的情况下,趋流率比较低,为50.00%左右,1 cm组在流速3 cm/s时的趋流率最高,达到98.67%;1 cm组的顶流率为96.65%,3 cm和4 cm组的顶流率仅为6.65%和3.35%。研究表明,斜带髭鲷和紫红笛鲷行为特征随着个体的发育而变化。     

漳州破灶屿网箱养殖区斜带髭鲷无公害养殖试验

本文描述了2002年12月~2004年1月间在龙海破灶屿网箱养殖区开展的斜带髭鲷无公害养殖试验。根据国家已建立的养殖用水水质、养殖环境和产品无公害标准规定的项目,对养殖生产过程的水域环境和产品进行检测;在养殖生产过程中,以无公害为目标,改进生产工艺。结果表明,龙海破灶屿网箱养殖区养殖环境符合无公害标准;从2003年3月19日~12月15日,将平均体长5.9 cm/尾、平均体重4.0g/尾的鱼苗饲养至平均体长24.9 cm/尾、平均体重420.9g/尾的规格,养成成活率60.1%,使用湿性颗粒饲料的饵料系数为5.2;养成产品符合无公害标准。     

海湾网箱养殖斜带髭鲷的生长特性

2002～2005年期间在广东省饶平柘林湾海上网箱采集斜带髭鲷Hapalogenys nitens标本共515尾,以鳞片的年轮作为年龄鉴定依据,对其生长特性进行研究。结果表明,1～5龄鱼体长与鳞长的关系式为L=175·17r 227·22,体长与体重关系式为W=0·0001L2·8677,体长与全长的关系式为Lt=1·1736Lb 3·6206,应用von Berta-lanffy生长曲线拟合生长规律,求得斜带髭鲷的各项生长参数为渐进体长L∞=452·418mm,W∞=4315·455g,体重生长曲线的曲率k=0·2799,理论上体长和体重为零时的年龄t0=-1·1869龄,体重生长拐点年龄t0=2·738龄。     

真蛸亲体培育、产卵及孵化试验

2005~2007年春、夏期间,在浙江南麂岛开展了真蛸亲体培育、产卵及孵化的试验研究。结果表明:亲蛸培育成活率为77.5%~95.5%,平均产卵率为68.0%~83.3%。不搭配雄体产卵率为65.0%,搭配一定比例的雄体后产卵率达92.5%,最高达100%。不同附卵器附卵效果以方形鲍鱼箱为最好,圆形鲍鱼皮桶次之,扇贝笼最差。在南麂海域暂养在网箱中的真蛸当水温上升到13.5℃以上时就开始有少量产卵,多数开始产卵在16.0℃左右,主要产卵期在4~6月。不同个体真蛸的产卵量变化很大,少者只有22 632粒,多者达170 684粒,平均102 665粒,平均每颗卵粒重量在1.670~2.207 mg之间,大小为长2.8~3.1 mm、宽0.915~0.950 mm。在水温13.5~28.0℃范围内,真蛸卵可以正常孵化,孵化率达60.0%~80.0%,超过28℃时孵化率明显下降。真蛸卵的孵化时间较长,至少需要20 d以上。孵化时间长短与水温关系密切,水温越高,孵化时间越短。孵化期间平均水温16.5℃,整个孵化时间长达47 d。当孵化期间平均水温为21.6℃时,从产卵到稚蛸出膜大致需要25 d左右。此外,还发现亲蛸护卵可以减少疾病,提高孵化率,本文也论述了有关其对疾病防治方面的探索。     

罗氏沼虾亲虾培育技术

利用对虾人工繁殖基地进行罗氏沼虾人工育苗。试验中采用偏低温、大水体、高水位、伴养水葫芦和鳙鱼、多种饵料组合、交叉投喂等技术培育亲虾。这些技术具有推广价值。     

鱼类产卵孵化方式及其适应意义

综述了卵生鱼类的浮性卵、粘性卵、沉性卵及特殊类型的产卵孵化方式及其适应意义,也描述了卵胎生和胎生鱼类的胚胎发育及产仔特征。     

Broodstock Rearing and Controlled Reproduction of Reeves Shad Tenualosa reevesii

Reeves shad Tenualosa reevesii is one of China's best known anadromous fish, but is presently on the verge of extinction. There is an urgent need for conservation of this species through artificial reproduction and culture. In this study, shad broodstock were held in captivity then were induced to spawn with serial injections of luteinizing hormone-releasing hormone analogue (LHRHa) following GtH priming by implantations of 17-methytestosterone (T) combined with environmental manipulations. Induced maturation of 4, 5, and 6-year-old females reached 83.3%, 87.5%, and 100%, respectively, while fish in control treatments remained immature. During the gonadal development priming period, mean serum 17-estradiol levels in the T treatment were significantly higher than the LHRHa treatment and control fish. Gonadal development of females was suppressed when their mesenteric fat index was below 1.5% by April. The effective accumulating temperatures for female and male maturation were 3,995 ± 31.4 C/d and 2,278 ± 8.9 C/d, respectively. Two injections of LHRHa in combination with domperidone (DOM) and environmental regulations were effective in inducing ovulation. About 800,000 fertilized ova were obtained (fertilization 75%) in 1995, and 5,000 fry were hatched in 1996. These results are an important step to develop shad culture and save this endangered species.     

Progress in Controlled Maturation and Spawning of Summer Flounder Paralichthys dentatus Broodstock

Abstract— Wild-caught, adult summer flounder Paralichthys dentatus (avg. wt. = 740 g; range = 264–1,540 g; N = 60), collected in northeastern US coastal waters during October 1994, were transported to Vero Beach, Florida in March 1995 and held in 2.6-m³ indoor tanks through November 1995 under two artificial photothermal regimes: (1) natural regime, simulating natural habitat conditions; and (2) accelerated thermal regime, with seasonal temperature changes advanced by one month. A third group of fish was held in outdoor tanks under ambient photothermal conditions. Under all photothermal conditions, onset of vitellogenesis was associated with declining daylength and temperature, beginning in the accelerated group, then progressing to the natural and the ambient groups. From 20 September to 28 November 1995, 23 vitellogenic stage females from the accelerated and natural regimes were implanted with a cholesterol-cellulose pellet containing LHRH-a (100 μg/kg body wt). Females with initial mean oocyte diameters ranging from 258–456 μm spawned voluntarily 2.5–5.5 d postimplantation, while no maturational response was obtained from females with mean diameters ranging from 165–231 μm. Two females were spawned twice during the study period by LHRH-a pellet implantation. Infrequent, natural spawning without hormone intervention was also obtained. Females released from 22.7–396.9 × 10³ eggs on the first day of spawning, with fertilization and hatching rates of 0–93.470 and 0–81.1%, respectively.     

影响半滑舌鳎生长发育的水环境因素

采用亲鱼强化培育、药物人工催产、自然产卵受精、人工授精、水泥池微流水孵化及鱼苗室外池塘培育方式,进行了锦鲤的亲鱼培育与规模化人工繁育,试验取得了良好的效果。采用LHRH-A3与DOM混合胸腔一次注射法催产140组锦鲤亲鱼,结果138尾雌鱼顺产,孵化出仔2500万尾。对230万尾仔鱼进行了规模化培育,共培育出3～5cm长的苗种150万尾,成活率65．2％。50万尾夏花鱼种经3次挑选,按照业内分级标准,选留了5万尾优质鱼种,其背部挺直,色彩鲜艳,图案斑纹清晰,品种特征明显。     

细鳞鱼发眼卵孵化及仔、稚鱼培育

采用人工催产和全人工授精技术对细鳞鱼进行繁殖,对受精卵进行流水孵化,孵化水温6℃～9℃,积温达到t40．150度日受精卵发眼率为90％。积温达到180～213度日发眼卵开始破膜孵出仔鱼,孵化率为84％～96％,仔鱼经10～12d的发育开始上浮平游成为稚鱼,采用生物饵料（水蚤）对仔鱼进行开口,转口期采用水蚯蚓＋饲料糜团进行驯化,稚鱼期利用全人工饲料进行培育。