青石斑鱼Epinephelus awoara仔、稚、幼鱼日龄和形态、生长发育的研究

STUDY ON DAILY AGE, MORPHOLOGY ANG GROWTH OF LARVA, FRY AND JUVFNILE OF EPINEPHELUS AWOARA

本文根据青石斑鱼仔、稚鱼形态变化划分为前仔鱼期、后仔鱼期、稚鱼期、幼鱼期。背、腹棘的显著伸长是石斑鱼形态发育过程中的一个典型特征。背棘、腹棘长短与仔鱼全长有明显关系。背棘和腹棘比值近似1:1。仔稚鱼全长和体重两者呈幂函数相关。在整个仔、稚、幼鱼日龄生长中可分为三个阶段,第一阶段为15日龄前的仔鱼阶段,第二阶段为40日龄前的仔稚鱼阶段,第三阶段为60日龄前的稚幼鱼阶段。各生长阶段均伴随着一个危险期。导致各危险期的主要原因是(1)饵料,(2)变态,(3)自残。对策是(1)确保适时、适口饵料供应,(2)防止水质恶化和饵料营养缺乏,(3)勤分苗和充分投饵。在生长发育中,石斑鱼个体大小差异显著,导致此现象出现是因先天性和后天性二个方面造成。

With the morphology changing of the larve and fry of Epinephelus awoara, four stages were divided that were the pre-larva, the post-larva, fry and juvenile. A typical feature in the morphological development of E. awoara, was the remarkable lengthening of pectoral spine and abdominal spine. There were the obvious relations to the length of pectoral and abdominal spine with the total length of fry. The ratio of pectoral spine and abdominal spine was about 1:1 It was the power function relativity for the total length and the weight of larva and fry. It were divided three stages in whole daily agc growth of larva, fry and juvenile that the first stage was larva before 15-day age; the second stage was larva and fry before 40-day age; and the third stage was fry before 60-day age. There were a danger stage in the respective growth stages. The main reasons which lead to the each danger stage were (1) food, (2) metamorphosis, (3) massacre for each other. The countermeasure were (1) to be sure to supply suitable food in suitable time, (2)to prevent the water quality deteriorating and food nutrition lacking, (3) to separate fry frequently and to feed sufficiently. The individual size difference were both the congenital and the acquired factors.