Early developmental patterns of the appendicular skeleton of Thamnaconus septentrionalis
The developmental patterns of appendicular bones in newly hatched larvae and 1-60 day larvae,post-larvae,and juvenile of Thamnaconus septentrionalis were observed using the cartilaginous and bony dou-ble-staining technique to determine the timing and key stages of ossification.The results revealed the following sequence of appendicular skeleton occurrence:pectoral fin(1 day),first dorsal fin(8 days),ventral fin(11 days),second dorsal fin(14 days),anal fin(14 days),and caudal fin(18 days).The ossification sequence was as follows:first dorsal fin(23 days),ventral fin(23 days),second dorsal fin(25 days),anal fin(25 days),caudal fin(25 days),and pectoral fin(27 days).The sclerogenous bone consisted of the spoon,posterior spoon,and caudal bones,with the coracoid bone differentiating into the scapula and black coracoid bone at 13 days.The first dorsal fin sclerosi-fied at 26 days,whereas the pectoral and pelvic fins sclerosified at 60 days.The development of branch bones,second dorsal fin,and anal fin occurred synchronously,and bone slices extending to the middle of the second fin were closely connected to each other at 60 days.The subcaudal bone,lateral subcaudal bone,supracaudal bone,and caudal fin strips of the tail became clearly visible on the 21st day.Of the 12 fin strips,8,1,1,and 2 bones were attached to the inferior caudal,superior caudal,caudal rod,and lateral subcaudal bones,respectively.This study fills the research gap in the skeletal development of larvae,juveniles,and early juveniles,provides a theoretical reference for breeding,enriches the data on skeletal morphology and developmental biology of fish,and contributes to the study of systematic differentiation and classification of fish.
万方数据
维普
