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.