斑点鳟仔、稚、幼鱼的形态发育

以斑点鳟(Oncorhynchus mykiss)发眼卵为材料,进行了发眼卵的人工孵化及仔鱼的人工培育研究。对斑点鳟仔稚鱼的形态发育进行了系统观察,描述了各发育期的形态特征,并测定生长参数。斑点鳟早期生活史的分期如下:初孵仔鱼全长14.25±0.45 mm,体重85±5 mg,肛门未开口,营内源性营养,脊柱末端向上弯曲;10 dph开始上浮,投喂卤虫;12 dph开口摄食,开始营内外源混合性营养;14 dph鳍膜消失,各鳍独立;16dph开始投喂配合饵料;24 dph卵黄囊吸收完毕,营完全外源性营养;34 dph,体侧形成8～9个幼鲑斑;44 dph各鳍的鳍条发育健全;60 dph幼鱼外形为纺锤形,与成鱼相同。研究表明,斑点鳟早期生长发育过程中全长、肛门前长、水平眼径和头高的生长情况基本相同,0～16 dph生长速度较快,16～44 dph生长速度较慢,44 dph后生长速度再次变快。

Morphological observation on larval and juvenile development of Oncorhynchus mykiss

The paper reported the results of morphological observation on larval development of Oncorhynchus mykiss.The eyed eggs obtained from America were used in this study.Morphological development of fish larvae was systematically observed.The paper described the morphological characteristics of various developmental stages and measured growth parameters.The early life history of Oncorhynchus mykiss was: the total length of newly hatched larvae was 14.25±0.45 mm,the weight was 85±5 mg;the anus was not open,the larvae relied on their yolk for nourishment,the end of spine was upwarped;the larvae started floating at 10 dph,fed with artemia;the larval mouth opened at 12 dph;the fin membrance disappeared at 14 dph;the yolk was exhausted at 24 dph;8-9 large black spots on the lateral formed at 34 dph;All fin rays and scales formed at 44 dph;the juvenile showed the appearence of small adults at 60 dph.The morphological development and changes of pigment pattern were observed.The development of head,dorsal spine,anal fin and caudal peduncle were described with 4 plates.The growth characters and feeding habits were discussed.