白点鲑胚胎与仔鱼发育

The Embryonic and Larval Development in Salvelinus leucomaenis

通过Bouin's液、5%的福尔马林、透明液固定和活体解剖观察等4种不同方法,对白点鲑(Salvelinus leucomaenis)胚胎和仔鱼发育进行了系统观察,描述了早期发育过程。白点鲑受精卵为端黄卵,沉性,橙黄色,呈圆球形。在水温3.40～8.89℃,受精卵历时1 944 h,经历6个阶段的胚胎发育破膜孵出仔鱼;初孵仔鱼全长(17.89±0.32)mm,破膜后73 d各鳍条发育完全,并出现"幼鲑斑",破膜后350d鱼体外部形态与成鱼基本相同。将白点鲑与几种鱼类进行了对比,并且探讨了其胚胎发育特点。经比较4种不同观察方法,Bouin's液固定后剥离卵膜观察是研究白点鲑等卵膜较厚鱼类的理想方法。

The embryonic and larval development in Salvelinus leucomaenis was studied for the first time by 4 different methods of fixation by Bouin＇s,by 5% formalin,by transparent agent and vivisectional observation.The zygote of S.leucomaenis was demersal,telolecithal,orange and spherical.At 3.40-8.89℃,the larvae with a yolk sac hatched after 6 stages of embryonic development which lasted for 1 944 h.The body of the newly hatched larvae measured 17.89 ± 0.32 mm in length.Pterygiophore developed completely and the＂parr.mark＂ appeared on the 73rd day post-hatch.On the 350th day the larvae were almost the same as adult fish in their appearance.The characteristics of the embryonic development in Saleucomaenis were discussed by comparison with other species.The ideal method for researching the eggs with thick membrane was to strip the membrane after eggs were fixed by Bouin＇s fluid.