喷点雪印小丑鱼的胚胎及仔、稚、幼鱼形态发育观察

Observation of embryo and morphological development of larval,juvenile and young speckled snowmark clownfish(Amphiprion sp.)

为建立喷点雪印小丑鱼(Amphiprion sp.)人工繁育技术,在人工模拟自然条件下对其繁殖习性、胚胎发育及胚后发育进行观察。结果表明:喷点雪印小丑鱼受精卵长径为1.9~2.1 mm,短径为0.93~0.95 mm;胚胎发育主要经历受精卵期→胚盘期→卵裂期→囊胚期→原肠胚期→神经胚期→器官形成期→孵化期等;在水温为(27±0.5)℃时,受精卵约需197 h孵化出膜。初孵仔鱼全长(4.415±0.412)mm,身体透明,鳍膜明显,卵黄囊仅剩小部分残留,并已开口摄食。9日龄全长(6.813±0.835)mm,鳍膜消失,各鳍基本形成,头部开始出现纹带,进入稚鱼期。21日龄全长(10.581±2.659)mm,身体被鳞,体色、纹路开始分化。35日龄全长(15.512±4.927)mm,形成4种不同体色、纹路的幼鱼。作为人工选育的品系,喷点雪印小丑鱼胚后发育过程中最为明显的变化是幼鱼期体色、纹路等形态特征的形成与分化。

In order to improve the artificial breeding technology of the speckled snowmark clownfish(Amphiprion sp.),we observed the breeding habits,embryonic development and post-embryonic development under artificial simulated natural conditions.The results show that the fertilized eggs were 1.9-2.1 mm in long diameter and 0.93-0.95 mm in short diameter.The embryonic development mainly went through sperm-egg stage,embryonic disc stage,oogenesis stage,blastocyst stage,protointestinal stage,neuroembryonic stage,organ formation stage and hatching stage.At the water temperature of(27±0.5)℃,it took approximately 197 h for the fertilized egg to hatch out of the membrane.The newly hatched larvae had a total length of(4.415±0.412)mm,a transparent body,obvious fin membranes,and only a small portion of the yolk sac remained,which had been opened for feeding.Larval stage:At 9 days after hatching[DAH,body length of(6.813±0.835)mm],the fin membrane disappeared and the fins formed,and the banding on the head appeared.Juvenile stage:at 21 DAH[Body length of(10.581±2.659 mm)],accompanied by scale formation on the body,the differentiation of body colour and stripe banding started to appear.Young stage:35 DAH[Body length of(15.512±4.927)mm],four different strains with different body colour patterns were easily identified.In brief,as an artificially selected new variety,the most obvious feature during the post-embryonic development of speckled snowmark clownfish is formation and differentiation of body colour patterns such as stripe banding during juvenile stage.