Morphological characteristics and distribution of Pleuronectidae (Pisces) eggs in the western margin of the East Sea

Abstract

Seven species of Pleuronectidae (Platichthys stellatus, Kareius bicoloratus, Pseudopleuronectes herzensteini, Microstomus achne, Glyptocephalus stelleri, Hippoglossoides dubius, and Limanda punctatissima) were identified based on eggs collected from the western margin of the East Sea (east coast of Korea), using DNA barcoding. The eggs of P. herzensteini and G. stelleri were relatively widely distributed along the east coast of Korea, whereas those of P. stellatus and K. bicoloratus were narrowly distributed; in particular, the eggs of P. stellatus were restricted to areas near bays. The eggs, which share common morphological characteristics (such as a homogeneous yolk and smooth membrane) were divided into three groups according to egg size: group A (more than 1.60 mm in egg diameter, including genera Hippoglossoides and Microstomus), group B (1.00–1.60 mm, including genera Kareius, Glyptocephalus, and Platichthys), and group C (less than 1.00 mm, including genera Limanda and Pseudopleuronectes). This paper provides an overview of the morphological characteristics of the eggs of the family Pleuronectidae collected from the east coast of Korea. Our approach to the analysis of eggs, based on DNA barcoding, morphological characteristics, and geographic distributions, provides a rapid and accurate basis for identifying spawning areas and spawning periods, thus facilitating the assessment and management of fisheries stocks and resources.