人工饲养和野生草鱼幼鱼耳石微结构的比较研究

分别检测了人工饲养和野生草鱼幼鱼的耳石微结构特征，根据耳石透明性的差异。可将微耳石划分出中央暗区和外部亮区两部分，饲养种群的耳石暗区大小和生长轮数目均大于野生种群，暗区和亮区的特征比较稳定。生长轮清晰，对比度好，宽度比较均匀；野生种群的耳石暗区和亮区表现形式多变。暗区的生长轮清晰或不清晰，亮区的生长轮清晰，但宽度波动较大，依据耳石微结构特征。可以对饲养和野生草鱼种群进行识别。

OTOLITH MICROSTRUCTURE OF HATCHERY-REARED AND WILD JUVENILES OF GRASS CARP,CTENOPHARYNGODON IDELLUS

The otolith microstructure of juvenile grass carp(Ctenopharyngodon idellus)sampled from hatchery and wild were examined and analyzed.The lapilli of juveniles could be divided into inner optically dense and outer low optically dense zones based on the difference of transparence.The size and increment numbers of optically dense zone in hatchery-reared individuals were bigger than that in wild individuals.Increments in optically dense and relatively low optically dense zones were both clear and regular in reared individuals.Increments were clear or unclear in optically dense zone,while clear,but with irregular width in low optically dense zone in wild individuals.The otolith opacity and transparence were probably controlled by average water temperature the juveniles experienced.The irregular width of increments in wild individuals was potentially induced by the fluctuations of food supply in nature.The difference of otolith microstructure could be used to discriminate between the reared and wild populations in the fish.