作　　者： ; ; ; ;

机构地区： 中国水产科学研究院黄海水产研究所

出　　处： 《动物学报》 2005年第6期1023-1033,共11页

摘　　要： 在水温23.4-24.0℃、盐度33.00、pH7.78-8.02的培养条件下,半滑舌鳎初孵仔鱼全长为3.55±0.161mm(n=60),依照公式4/3π.R/2.(r/2)2计算其卵黄囊体积为0.606±0.106mm3(n=60)。1日龄仔鱼,全长为4.99±0.211mm(n=10),卵黄囊体积较初孵仔鱼缩小近10倍,约为0.066±0.008mm3(n=10);2日龄,仔鱼的巡游模式建立,仔鱼全长为5.61±0.069mm,卵黄囊体积为0.030±0.002mm3(n=10),口初开;2.5日龄,口完全裂开,口裂0.24±0.024mm(n=10),仔鱼进入摄食期;3日龄,仔鱼的外源性摄食关系初步建立;4日龄,仔鱼的摄食率达100%,完成了内源性营养向外源性营养的转换;5日龄,仔鱼的卵黄完全被吸收,仅剩聚成一团的小油球,仔鱼的混合营养期持续2.5天时间;21日龄,稚鱼全长为12.96±0.611mm(n=11),仍有40%的个体残余的油球还没有完全被吸收,其体积仅为0.0000005±0.000003mm3(n=11)。仔鱼发育过程中,其长度的生长存在内源性营养阶段的快速生长、混合营养阶段的慢速生长以及饥饿期间的负生长三个生长期相,平均增长率为0.45mm/d,依照TL=aD3+bD2+cD+d方程式对仔鱼的全长与日龄进行回归,其生长模型为TL(mm)=0.0026D3-0.0704D2+0.7993D+3.55(R2=0.9811,n=324)。仔鱼耐受饥饿的时间临界点发生在孵化后第10天(即9日龄)。仔鱼具有摄食能力的时间约6天,不可逆转饥饿期的时间约3天。残余的油球较长时间的存在,相对地延长了仔鱼混合营养期的时间,对仔鱼的发育、生长和存活有着至关重要的作用。5-20日龄的个体都具有胸角这个明显的形态学特征,只是饥饿个体和不可逆转饥饿期个体的胸角比摄食个体更为明显和尖锐,胸角不能作为区分健康仔鱼和饥饿仔鱼的形态学依据之一[动物学报51(6)1023-1033,2005]。 Experiments were performed in the Shandong Laizhou Mingbo Fish Farm from 8 th October to 1 st November, 2003. Adult tonguefish Cynoglossus semilaevis, caught in the Laizhou Bay of the Bohai Sea, were domesticated in indoor concrete ponds. After artificial inducement by controlling sueh environmental factors as temperature and illumination, gonads of the adult fish reached full development. At 11 p.m. , 8th October, the female ovulated, while the male ejaculated in the same pond and completed fertilization. Until midday （11 a. m. to 01 p. m. ） on 9th October, 160 thousand fertilized eggs were collected and transferred to another pond for incubation. The hatchery pond was maintained at temperatures of 23.6-24.0℃ , salinity 32.00and pH 8.0. At 8 a.m.on 10th October, all the collected eggs had hatched. At 3 p.m.on 11th October, about 140 thousand larvae were obtained for both seedling rearing and starvation tests. The newly-hatched larvae were collected, placed and cultivated in a round concrete pond with a bottom area of 10 m^2 and 1.5 m in depth. Water exchange volume was daily maintained in proportion of 20% to 30% of the total volume. The larvae were fed rotifers Brachionus plicatilis which were nourished with unicellular algae （ Chlorella sp. ） and rationed at a food density from 5 ind./ml （in the third day after hatched-out） to 10 ind./ml （fourth day after hatching） according to feeding status. The 15-day-old post-larvae were fed nauplii of brine shrimp Arternia salina at a food density of 2 3 ind./ml, while, the density of unicellular algae was maintained at 10 × 10^4 cell/ml. Since the 15th day after hatching, the density of unicellular algae was gradually decreased to 5 × 10^4 cell/ml. Seawater came from the natural seawaters after settlement and filtration. Normally, changing or adding water was conducted in the morning. Foods were supplemented twice a day, i.e. , one after changing water every morning and at 5 p.m. Some 800 larvae were randomly dredged and placed in a blue, round plast

关 键 词： 半滑舌鳎 仔鱼 初次摄食率 生长 不可逆转点 胸角

领　　域： [生物学] [农业科学] [农业科学]