南方鲇仔幼鱼耳石日轮的研究

A STUDY OF THE DAILY GROWTH INCREMENTS OF OTOLITHS IN THE LARVAE AND JUVENILE OF SILURUS SOLDATOVI MERIDIONALIS CHEN

南方鲇仔鱼耳石在孵化出膜 2 4h内出现第一条日轮 ,此后每天增加一轮。日轮由两条纤细轮组成 ,其形成与光照无密切关系 ,南方鲇耳石上存在孵化轮。耳石日轮轮纹数、日轮直径与日龄及体长呈直线相关 :S=1.0 2 2 4D - 0 .5 171 (r=0 .993 6,P <0 .0 0 1) ;R =0 .0 2 86+ 0 .0 179D (r=0 .993 6,P <0 .0 0 1) ;L =5 .765 5 + 4 9.6642R (r=0 .995 3 ,P <0 .0 0 1)。

The first increment was formed in the otolith of Silurus soldatovi meridionalis in 0～24 hours after hatching, and one more increment formed each day ever since. The growth increment was found to consist of two slim rings, whose formation was not related to sunlight. A hatching cheek ring was observed in the otolith. The number and diameter of the daily increments in the otolith were in a linear correlation with age in days and body length of the fish.