First record of Bathygobius hongkongensis (Perciformes: Gobiidae) from Jeju Island, Korea

Hyuck Joon Kwun

doi:10.1186/s41240-020-00164-9

Abstract

Six specimens of Bathygobius hongkongensis were collected for the first time from the eastern coast of Jeju Island, Korea, in September–November 2017. This species is characterized by a pectoral fin with free rays and the division of the first dorsalmost pectoral free ray into three branches; a lower jaw with a mental frenum; and an anterior nostril with a tiny flap. Bathygobius hongkongensis is similar to B. fuscus but differs in having more dorsalmost free pectoral fin rays. The new Korean name proposed for B. hongkongensis is “Nam-bang-mu-nui-mang-duk.”

Highlights

Jeju Island, the largest and most southern island of Korea, is the habitat for many subtropical and temperate marine fishes (Kim 2009), and various fish species have recently been reported for the first time in its coastal waters, including in tidal pools (Jang et al 2018; Kim et al 2018; Kwun et al 2016)
Jeju Island is affected by the Kuroshio Warm Current (Kim et al 2009), so it can be regarded as the boundary area in which tropical and subtropical fishes first appear in Korean waters
Six specimens of B. hongkongensis were collected with a hand net from a tidal pool on the eastern coast of Jeju Island between September and November 2017 (Fig. 1), and were fixed as whole bodies in 99% ethanol

Summary

Introduction

Jeju Island, the largest and most southern island of Korea, is the habitat for many subtropical and temperate marine fishes (Kim 2009), and various fish species have recently been reported for the first time in its coastal waters, including in tidal pools (Jang et al 2018; Kim et al 2018; Kwun et al 2016). The genus Bathygobius Bleeker 1878 is a representative group of this family, and 28 species are recognized worldwide (Froese and Pauly 2019). This genus is characterized by a chin with a mental frenum and free tips of the upper pectoral fin rays (Akihito et al 2013; Larson and Murdy 2001). In Korea, only one species of the genus, Bathygobius fuscus (Rüppell 1830) has been reported until now (Kim et al 2005)

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Conclusion