在水温(28.59±1.74)℃下,选用冰鲜杂鱼饲养平均体质量为858.73 g的鞍带石斑鱼,经过60 d的生长实验,研究了不同投喂频率(1次/d、1次/2 d、1次/3 d)对流水养殖鞍带石斑鱼生长、摄食及免疫酶活力的影响.结果表明,投喂频率对鞍带石斑鱼存活率的影响差异不具有统计学意义(p＞0.05),实验期间各个实验组存活率在99.40％～99.80％之间;各实验组间的肥满度(CF=2.22～2.35)、体质量变异系数(SV=20.08～24.27)、饲料系数(FCR=2.70～3.01)和日增质量(7.50～12.51g/d)均无显著影响(p＞0.05),而投喂频率1次/d组和1次/2d组的特定生长率(SGR)和相对增质量(RWG)均显著高于1次/3 d组(p＜0.05),投喂频率1次/d组的日摄食率和1次/2d组的饲料转化效率均显著高于1次/3 d组(p＜0.05);在免疫酶活力方面,投喂频率对鞍带石斑鱼血浆中的碱性磷酸酶(AKP=0.083 5～0.089金氏单位/mL)、过氧化氢酶(CAT=7.96～8.19 U/mL)及超氧化物歧化酶(SOD=32.40～34.45 U/mL)均无显著影响(p＞0.05).在本实验条件下,流水模式养殖鞍带石斑鱼的适宜投喂频率为1次/d或1次/2d.

We measured the body mass and seven morphometric traits of hybrid groupers (Epincphelus coioides ♀ × E.akaara ♂) and their parents to analyze the relationship between morphometric traits and body mass using path analysis,and then obtained multivariate regression equations.The results show that the correlation coefficients between body mass and morphometric traits have very significant difference in all three groupers (P ＜ 0.01).The total length and body mass had the highest correlation coefficient both in E.coioides and E.akaara,being 0.946 and 0.932,respectively.But for hybrid groupers,the highest correlation coefficient was between caudal peduncle depth and body mass (0.955),and the correlation coefficient between total length and body mass was 0.927.The multivariate regression equation of E.coioides retained standard length,body height,caudal peduncle depth and body width.The multivariate regression equation of E.akaara retained total length,body height and caudal peduncle depth.The multivariate regression equation of hybrid groupers retained total length,body height,caudal peduncle depth and body width.The analysis of heterosis in hybrid groupers found obvious average heterosis,while the negative (compared with male parents) and positive (compared with female parents) heterobeltiosis were found in hybrid groupers.The average heterosis of hybrid groupers in body mass and standard length were 3.43％ and 3.02％,respectively.It is revealed that the difference between hybrid groupers and female parents is less than the difference between that and male parents,and the hybrid groupers resemble female parents in morphological traits.

对云纹石斑鱼(♀)与鞍带石斑鱼(♂)杂交子代胚胎及仔稚幼鱼的生长发育进行了观察与研究.在水温(22±1)℃、盐度33、pH7.8的海水中,杂交受精卵经过35 h 23min完成整个胚胎发育.胚胎发育可分为卵裂期、囊胚期、原肠期、神经胚期和器官形成期,其中在卵裂期、囊胚期和仔鱼出膜前后,杂交子代胚胎的死亡率较高.杂交石斑鱼的孵化率为91.5％,低于对照组的93.1％;畸形率为10.5％,高于对照组的5.3％.根据杂交子代卵黄囊消失与否、第二背鳍棘和腹鳍棘的生长与收缩、体色和鳞片的出现,可将杂交石斑鱼胎后发育分为:前期仔鱼(0～3日龄)、后期仔鱼(4～27日龄)、稚鱼期(28 ～45日龄)、幼鱼期(46日龄以后);通过与其亲本早期发育进行比较发现,云纹石斑鱼(♀)与鞍带石斑鱼(♂)杂交子代具有一定的杂交优势.

一、前言 石斑鱼属鮨科(Serranidae)、石斑鱼亚科(Epinephelinae)、石斑鱼属(Epinephelus).石斑鱼肉质细嫩、营养丰富,经济价值较高,深受消费者和养殖者的喜爱,具有广阔的前景. 当前,循环水养殖作为一种新的模式,由于其具有节水、环保、高产、不受地域和气候限制等优势,被认为是海水养殖业的重要发展方向之一,迅速兴起和发展.

In this paper,we studied effect of the breeding density and water quality on Epinephelus coioides in the growth,feed coefficient and immunity. Total 450 groupers whose average weight was 146. 3 g / tail were divided into three experiment densities. The initial densities were 14. 6,21. 7 and 29. 5 kg / m3,respectively. The results showed that,the content of ammonia-nitrogen was influenced significantly( P < 0. 05) by the stocking density,and the feeding rate of Epinephelus coioides showed a significant negative correlation with the ammonia-N maintained time and concentration. Under the same experiment conditions,higher stocking densities have a negative effect on fish growth. The specific growth rate of the three treatments was 1. 07, 0. 60 and 0. 47,respectively. With the augmentation of density,the weight of experiment groups showed a significant difference,in which the weight gain of each treatment was 118. 5,63. 3 and 44. 1 g,respectively. It was also found that the stocking density had insignificant impact on feed coefficient rate and survival rate. The immunity content of lysozyme( LZM),alkaline phosphatase( AKP) and superoxide dismutase( SOD) decreased with increased density,and showed a trend of increase at first and then decreased with the extension of culture period. The article revealed that one mechanisms of breeding density influenced Epinephelus coioides growth,maybe density caused water quality to change,which in turn affects the feeding rate of Epinephelus coioides,and resulting in the significant difference in growth performance of different density grouper.