New record of Neoclinus lacunicola (Actinopterygii: Perciformes: Chaenopsidae) from Ulleung Island, Korea revealed by body morphometry and mitochondrial DNA barcoding

One specimen (38.3 mm SL) of Neoclinus lacunicola Fukao, 1980, belonging to the family Chaenopsidae, was first recorded from Ulleung Island, Korea (East Sea, otherwise known as the Sea of Japan) on 5 January 2021. This species was characterized by paired external pores of incomplete lateral line running from the upper margin of the opercle, seven pairs of supraorbital cirri arranged in two rows, occipital region with a pair of cirri, and 13 rays of pectoral fin. This species is morphologically similar to the Neoclinus toshimaensis Fukao, 1980, but differs in the number of cirri on the supraorbital (6–7 versus 9–11 cirri). This study documents the first report of N. lacunicola in Korean waters and proposes the new Korean name of ‘eol-lug-bi-neul-be-do-la-chi’ for the species. For the confirmation of the identity of the species, a partial gene sequence of the mt COI (570 bp) of N. lacunicola was obtained for the first time.

Genome-Wide Single Nucleotide Polymorphism Analysis Elucidates the Evolution of Prunus takesimensis in Ulleung Island: The Genetic Consequences of Anagenetic Speciation

Of the two major speciation modes of endemic plants on oceanic islands, cladogenesis and anagenesis, the latter has been recently emphasized as an effective mechanism for increasing plant diversity in isolated, ecologically homogeneous insular settings. As the only flowering cherry occurring on Ulleung Island in the East Sea (concurrently known as Sea of Japan), Prunus takesimensis Nakai has been presumed to be derived through anagenetic speciation on the island. Based on morphological similarities, P. sargentii Rehder distributed in adjacent continental areas and islands has been suggested as a purported continental progenitor. However, the overall genetic complexity and resultant non-monophyly of closely related flowering cherries have hindered the determination of their phylogenetic relationships as well as the establishment of concrete continental progenitors and insular derivative relationships. Based on extensive sampling of wild flowering cherries, including P. takesimensis and P. sargentii from Ulleung Island and its adjacent areas, the current study revealed the origin and evolution of P. takesimensis using multiple molecular markers. The results of phylogenetic reconstruction and population genetic structure analyses based on single nucleotide polymorphisms detected by multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq) and complementary cpDNA haplotypes provided evidence for (1) the monophyly of P. takesimensis; (2) clear genetic differentiation between P. takesimensis (insular derivative) and P. sargentii (continental progenitor); (3) uncertain geographic origin of P. takesimensis, but highly likely via single colonization from the source population of P. sargentii in the Korean Peninsula; (4) no significant reduction in genetic diversity in anagenetically derived insular species, i.e., P. takesimensis, compared to its continental progenitor P. sargentii; (5) no strong population genetic structuring or geographical patterns in the insular derivative species; and (6) MIG-seq method as an effective tool to elucidate the complex evolutionary history of plant groups.

Genetic Diversity and Population Structure of the Spring Orchid Cymbidium goeringii in Korean Distant Islands

The spring orchid (Cymbidium goeringii), found in northeast Asia, is one of the most popular and horticulturally important species of the orchid family. This study analyzed the genetic diversity and population structure of the spring orchid populations in the small islands and mainland South Korea using 11 microsatellite markers. The genetic diversities of spring orchid populations in the distant islands (Heuksan Island and Ulleung Island) were slightly lower than that of the mainland population (Yeonggwang-gun). The population structure in the mainland was genetically separated from the populations in the islands. The population of Ulleung Island, located in the eastern part of the Korean peninsula, was genetically closer to the populations from China and Japan than to the populations from Yeonggwang-gun and Heuksan Island, which are geographically close to China. These results imply that the populations of spring orchids distributed in Yeonggwang-gun and Heuksan Island appear not to be influenced by the yellow dust winds. As the first population genetic study of spring orchids distributed in small distant islands, our study will be useful for understanding the genetic diversity and population structure of isolated C. goeringii populations.