光唇鱼网箱养殖试验

网箱单养、混养光唇鱼的试验结果表明,在25m2网箱中,单养光唇鱼以200～220尾/m2的放养密度比较合适,单位面积产量可达12.7～12.9 kg/m2;瓯江彩鲤网箱中混养光唇鱼,在瓯江彩鲤保持180尾/m2的放养密度不变的情况下,混养20尾/m2的光唇鱼,其效果比单养瓯江彩鲤更好,单位面积产量可达103.2kg/m2.     

外源人绒毛膜促性腺激素诱导黑边石斑鱼排卵的研究

【目的】了解外源人绒毛膜促性腺激素(human chorionic gonadotropin,HCG)诱导黑边石斑鱼(Epinephelus fasciatus)排卵的影响。【方法】以成熟的黑边石斑鱼为研究对象,测量其体长、体质量和肥满度后,在2018年7—8月,使用HCG激素(剂量为200 IU/kg或500 IU/kg)注射分别对6尾雌鱼进行成熟诱导。【结果】在200 IU/kg HCG处理中,注射24 h前有5尾雌鱼的卵母细胞处于第三次卵黄球前期阶段;注射48 h后2尾雌鱼出现核移动卵母细胞,1尾雌鱼的卵母细胞为第三次卵黄球后期阶段;注射60 h后1尾雌鱼出现排卵现象,其余5尾雌鱼均为第三次卵黄球后期阶段。在200 IU/kg HCG处理的排卵个体中,注射时其卵母细胞直径为477.0 μm,注射后60 h卵母细胞的直径增加至624.4 μm。此外,经催产、排卵、受精和孵化后共获得总卵数16 906粒,受精率为68.7%,孵化率为43.0%。而500 IU/kg HCG处理的黑边石斑鱼排卵失败。【结论】使用剂量为200 IU/kg的外源HCG激素可诱导黑边石斑鱼成熟且排卵,但为了提高排卵率、受精率和孵化率,其注射剂量和效应时间还需要进一步调节。     

条石鲷胚胎及仔稚鱼的发育

通过对条石鲷胚胎发育和仔鱼发育形态的观察，确定了条石鲷早期发育的进程。条石鲷的受精卵为圆球形、透明、浮性，卵径为0．90～0．95mill，油球1个，卵裂为盘状卵裂。在水温23～24℃，盐度26～28的条件下，受精后7h 10mirh胚胎发育至原肠期；受精后12h，眼囊形成；受精后20h 30min，心跳开始搏动；受精后26h 30min仔鱼孵出。初孵仔鱼全长1．78～2．03min，至5日龄全长3．25～3．30min时，卵黄囊完全消失；至8～15日龄，全长3．50～4．97mm时，鳔形成；至18．20日龄，全长7．10～7．31min时，尾鳍鳍条发育完整。     

松江鲈鱼初期胚后发育阶段消化系统组织学的初步研究

实验通过对松江鲈鱼(Trachidermus fasciatus Heckel)仔鱼的消化道进行从口腔到尾部的连续切片,观察其消化道的组织学结构。结果表明:①松江鲈鱼仔鱼在出膜后1d与2d的消化道组织结构简单,肠腔部分位置堵塞,未见畅通,仔鱼靠自身的卵黄囊进行营养。②出膜3d后的松江鲈鱼仔鱼消化道畅通,可进行主动摄食。了解到这一情况,并根据其当时精确的口径大小,可为解决松江鲈鱼仔鱼开口时间与选择合适开口饵料提供理论依据。     

条石鲷消化道的形态学和组织学

采用解剖和光镜技术研究条石鲷消化道的形态学和组织学。条石鲷消化道包括具有发达颌齿的口咽腔，食道，胃，小肠和直肠。食道上皮组织可分为两个区域－头部和尾部，头部区域由扁平上皮层构成，尾部区域的上皮组织由单层柱状上皮细胞所构成，上皮含有大量 杯状细胞和黏液分泌细胞.胃呈V形，其粘膜上皮由单层柱状上皮组成，贲门部和胃体部上皮下有发达的胃腺组织。小肠上皮为具微绒毛的单层柱状上皮，肠道粘膜固有层中有管状肠腺存在；直肠上皮为单层柱状上皮，缺乏粘膜肌。小肠和直肠上皮中均分布有较多的杯状细胞，肠道系数约为0.78。在整个消化道中发现有四种杯状细胞。本文研究了条石鲷消化道的显微结构，并探讨了其消化道的组织学和解剖学特征与其杂食性的适应。     

条石鲷胚胎及仔稚鱼的发育

通过对条石鲷胚胎发育和仔鱼发育形态的观察，确定了条石鲷早期发育的进程。条石鲷的受精卵为圆球形、透明、浮性，卵径为0．90～0．95mill，油球1个，卵裂为盘状卵裂。在水温23～24℃，盐度26～28的条件下，受精后7h 10mirh胚胎发育至原肠期；受精后12h，眼囊形成；受精后20h 30min，心跳开始搏动；受精后26h 30min仔鱼孵出。初孵仔鱼全长1．78～2．03min，至5日龄全长3．25～3．30min时，卵黄囊完全消失；至8～15日龄，全长3．50～4．97mm时，鳔形成；至18．20日龄，全长7．10～7．31min时，尾鳍鳍条发育完整。     

Synthesis and biological activity of furanyl anti-juvenile hormonal compounds

Twenty-one synthetic compounds, containing one or more furan rings, were demonstrated to possess anti-juvenile hormone (AJH) activity as evidenced by their induction of premature metamorphosis in the milkweed bug, Oncopeltus fasciatus (Dallas) by contact, topical application or fumigation. The ED₅₀ of the four most active analogs required to induce precocious metamorphosis from 3rd-instar nymphs by residue contact in a Petri dish compared favorably with that of precocene II (6,7-dimethoxy-2,2-dimethyl 2H-chromene) a naturally occurring phytochemical AJH. Precocious metamorphosis was fully reversible by co-treatment with juvenile hormone (JH III) or JH analogs, demonstrating that the observed AJH activity resulted from an induced deficiency of juvenile hormone.     

Dietary eicosapentaenoic acid requirement of juvenile rock bream,Oplegnathus fasciatus

A feeding trial was conducted to evaluate the optimum dietary level of eicosapentaenoic acid (EPA, 20:5n‐3) based on growth and non‐specific immune responses in juvenile rock bream. A basal diet without EPA supplementation was used as a control, and six other diets were prepared by supplementing with 4, 8, 12, 16, 20 or 40 g of EPA per kg diet. The actual EPA concentrations of the diets were 0.5, 4.3, 8.5, 13.0, 16.8, 21.0 and 41.2 g of EPA per kg diet, and the diets were abbreviated as EPA_0.5, EPA_4.3, EPA_8.5, EPA_13.0, EPA_16.8, EPA_21.0 and EPA_41.2, respectively. Triplicate groups of fish averaging 1.06 ± 0.01 g (mean ± SD) were fed one of the seven experimental diets at the apparent satiation for 8 weeks. At the end of the feeding trial, weight gain, specific growth rate and feed efficiency of fish fed EPA_16.8, EPA_21.0 and EPA_41.2 diets were significantly higher than those of fish fed EPA_0.5, EPA_4.3, EPA_8.5 and EPA_13.0 diets (p < .05). Superoxide dismutase activity of fish fed EPA_16.8, EPA_21.0 and EPA_41.2 diets were significantly higher than those of fish fed EPA_0.5, EPA_4.3 and EPA_8.5 diets. Fish fed EPA_21.0 and EPA_41.2 diets showed significantly higher lysozyme activity than did fish fed EPA_0.5, EPA_4.3, EPA_8.5 and EPA_13.0 diets. The broken‐line analysis of weight gain indicated that the optimum dietary EPA level was 16.7 g/kg diet. These results suggested that the optimum dietary EPA level in juvenile rock bream could be greater than 16.7 g/kg diet but less than or equal to 16.8 g/kg diet based on the broken‐line analysis and the ANOVA test of weight gain.     

不同健康程度和抗生素氟苯尼考干预下斑石鲷肠道菌群的结构差异

为了研究不同健康程度和抗生素氟苯尼考干预下斑石鲷肠道菌群结构的差异及其与养殖环境中菌群结构的相关性,采用Illumina Hi Seq PE250高通量测序的方法对健康、亚健康、典型黑身病和口服氟苯尼考条件下的斑石鲷肠道、养殖水体和颗粒饵料中的细菌多样性及群落结构进行了分析比较。结果显示,养殖水体中细菌多样性高于肠道和颗粒饵料。不同健康程度及氟苯尼考干预下斑石鲷肠道中细菌均以变形菌门、厚壁菌门和软壁菌门为主,且对应的操作分类单元(OTU)占样品全部OTU的比例均达到85%以上。黑身病的发生可影响斑石鲷肠道中丰度最高的前20种优势细菌种类的排名次序,其中变形菌门中的弧菌属的相对丰度显著增加,且随着弧菌属丰度的增加,斑石鲷的黑身病症状也逐渐加重。饵料中添加氟苯尼考投喂斑石鲷能使患病鱼肠道弧菌属的丰度从60.33%下降到1.29%,较大程度改变了肠道的菌群结构,并证实氟苯尼考有效防治黑身病。其次,养殖水体和颗粒饵料对斑石鲷肠道菌群也有一定影响,且养殖水体的影响高于颗粒饵料。本研究首次报道了斑石鲷肠道菌群结构,其研究结果为今后斑石鲷的健康养殖、疾病防控及其微生态学研究提供了参考依据和技术支撑。     

光唇鱼幼鱼对9种常用药物的耐受性试验

[目的]研究光唇鱼幼鱼对9种常用药物的耐受性。[方法]采用静水式试验方法,将光唇鱼幼鱼放在不同浓度的9种药物溶液中进行耐受性试验,对光唇鱼幼鱼的急性致毒效应特征和9种药物的安全浓度进行评价。[结果]光唇鱼幼鱼在9种药物溶液中1 h最高成活浓度分别为:食盐为10 000 mg/L,高锰酸钾为20 mg/L,甲醛为108 mg/L,硫酸铜为10 mg/L,氯氰菊酯为0.013 mg/L,伊维菌素为0.020 mg/L,阿维菌素为0.030 mg/L,辛硫磷为0.030 mg/L,水霉净为80 mg/L。光唇鱼幼鱼对各种药物的敏感性由高到低依次为:氯氰菊酯﹥伊维菌素﹥阿维菌素﹥辛硫磷﹥水霉净﹥硫酸铜﹥甲醛﹥高锰酸钾﹥食盐。[结论]该研究为高密度流动水体养殖条件下的鱼病防治用药提供参考。