Morphological Development and DNA Barcoding Identification of Pholis fangi Larvae and Juveniles in the Yellow Sea

Pholis fangi is a small, bottom-dwelling fish species endemic to the Yellow Sea and Bohai Sea in China. While previous research has focused on its population biology and molecular structure, little is known about the early developmental stages of this species. In this study, larval and juvenile P. fangi specimens were collected from the Sheyang Sea Area, Jiangsu Province, in 2017. Morphological features were examined using microscopy, and DNA barcoding was conducted to confirm species identification. The research documented detailed changes in yolk sac, fin development, and melanophore distribution patterns across larval and juvenile stages of P. fangi. Comparative analysis with other Pholis species revealed that melanophore distribution is a key distinguishing characteristic, allowing effective differentiation between larval and juvenile stages, as well as between Pholis species. This study provides valuable insights into the early life history of P. fangi, contributing to a better understanding of the genus Pholis. The findings demonstrate the utility of combining traditional morphological observation and molecular techniques for accurate species identification, particularly during the critical larval and juvenile developmental phases.