National Institute of Aquatic Resources, Technical University of Denmark, P.O. Box 101, DK-9850 Hirtshals, Denmark.
J Fish Biol. 2009 Aug;75(3):516-37. doi: 10.1111/j.1095-8649.2009.02301.x.
An experimental study was performed to disentangle parental and environmental effects on the growth of Atlantic cod Gadus morhua larvae and juveniles. Eggs were collected during the spawning season from spawning pairs (families) kept separately in specially designed spawning compartments. Newly hatched larvae were released simultaneously into two mesocosms of 2,500 and 4,400 m(3). Larval growth was monitored by sampling over a 10 week period, after which juveniles were transferred to on-growing tanks, where they were tagged and kept for up to 2 years. Maternal origin was determined by individual microsatellite genotyping of the larvae (n = 3949, 24 families) and juveniles (n = 600). The results showed significant positive correlations between egg size and larval size during the whole mesocosm period. Correlations, however, weakened with time and were no longer significant at the first tank-rearing sampling at an age of 9 months. Significant family-specific differences in growth were observed. The coefficient of variation (c.v.) was calculated in order to examine variation in standard length of larvae during the mesocosm period. Inter-family c.v. was on average 69% of intra-family c.v. Differences in zooplankton densities between the two mesocosms were reflected in larval growth, condition factor and c.v. Low food abundance appeared to reduce c.v. and favour growth of larvae that showed relatively slow growth at high food abundance. It is suggested that genetically determined variation in growth potential is maintained by environmental variability.
一项实验研究旨在厘清亲代和环境效应对大西洋鳕鱼（Gadus morhua）幼鱼和仔鱼生长的影响。在产卵季节，从分别饲养在专门设计的产卵隔室中的产卵对（家系）中收集卵子。刚孵化的幼鱼同时被释放到两个 2500 和 4400 立方米的中密度养鱼缸中。在 10 周的监测期间，通过抽样监测幼鱼的生长情况，然后将幼鱼转移到生长水箱中，在那里对其进行标记并饲养长达 2 年。通过对幼鱼（n = 3949，24 个家系）和仔鱼（n = 600）进行个体微卫星基因分型来确定母本来源。研究结果表明，在整个中密度养鱼缸期间，卵大小与幼鱼大小之间存在显著的正相关关系。然而，随着时间的推移，这种相关性减弱，在 9 个月龄的第一次水箱养殖采样时不再显著。观察到生长存在显著的家系特异性差异。为了检查中密度养鱼缸期间幼鱼体长的变化，计算了变异系数（CV）。家系间的 CV 平均为家系内 CV 的 69%。两个中密度养鱼缸之间浮游动物密度的差异反映在幼鱼的生长、体况因子和 CV 上。低食物丰度似乎降低了 CV，并有利于在高食物丰度下生长缓慢的幼鱼生长。研究表明，由环境变异性维持的生长潜力的遗传决定变异。
