A new species of prickleback, Dictyosoma tongyeongensis (Perciformes: Stichaeidae) from the South Sea of Korea

Abstract

A new prickleback is described based on six specimens collected by fish trap in southern Korea (water depth 5-12 m) in 2009 and 2010. The new prickleback is most similar to Dictyosoma burgeri and Dictyosoma rubrimaculatum in general morphology, but differs in the following combination of characters: dorsal contour of head almost a straight line; anal-fin rays 45-47; vertebrae 70-74; no blackish-brown blotches on head. In addition, mitochondrial DNA cytochrome oxidase subunit I (COI) sequences and recombination activating gene 2 (RAG2) sequences were analyzed for clarifying their genetic relationship. The neighbor-joining tree using mtDNA COI and nDNA RAG2 shows the reciprocal monophyly of the new prickleback. Accordingly, our specimens are regarded as a new species, named Dictyosoma tongyeongensis, after its type locality (Tongyeong).

First Japanese Record and a Revised Diagnosis for Dictyosoma tongyeongensis (Osteichthyes: Perciformes: Stichaeidae)

“…Cephalic sensory pore counts followed Makushok (1958) and Yamanaka et al (2012). Terminology of the lateral-line canals follows Yatsu et al (1978) and Ji and Kim (2012). The number of vertical branches connecting the second and third lateral-line canals before the anus was counted at the level of the second lateral-line canal.…”

“…The number of vertical branches connecting the second and third lateral-line canals before the anus was counted at the level of the second lateral-line canal. The diagnosis of D. tongyeongensis given here is based on specimens from both Japan and Korea [comparative materials in this study and Ji and Kim (2012)] while the present description is based on specimens from Japan. Institutional abbreviations are as fol-lows: Kochi University, Kochi, Japan (BSKU), Kyoto University, Kyoto and Maizuru, Japan (FAKU), National Institute of Biological Resources under the Ministry of Environment, Korea (NIBR), National Museum of Nature and Science, Tsukuba, Japan (NSMT), Osaka Museum of Natural History, Osaka, Japan (OMNH), Pukyoung National University, Busan, Korea (PKU), and Naturalis-National Natuurhistorisch Museum, Leiden, Netherlands (RMNH).…”

“…Dictyosoma tongyeongensis was originally diagnosed as having no blackish-brown blotches on the head (i.e., above the upper end of the opercle) and a single white oblique band on the cheek (Ji and Kim 2012). However, one of the paratypes (PKU 3568) has a distinct dark blotch above the upper end of the opercle (Fig.…”

“…A phylogenetic analysis by Yatsu (1986), based on morphological characters and focused on Xiphisterini (Xiphisterinae sensu Makushok 1958), defined Dictyosoma on the basis of several synapomorphies, including reticulate lateral lines and one postcleithrum. Although the genus had long been considered to include only two species, Dictyosoma burgeri van der Hoeven, 1855 and Dictyosoma rubrimaculatum Yatsu, Yasuda, andTaki, 1978, Yatsu et al (1978) recognized two geographic forms ("a" and "b") in their D. burgeri, the former occurring on the Pacific coast of Japan from Shizuoka to Chiba Prefectures, and the latter on the Sea of Japan (East Sea of Korea) and East China Sea coasts of Japan from Nagasaki northward to Hokkaido, the Pacific coast of northern Honshu Is., Japan, and southern coast of the Korean Peninsula (Yatsu et al 1978;Ji and Kim 2012). Because of morphological differences between the forms, including counts of dorsal-fin spines, anal-fin rays, and total vertebrae, Mecklenburg and Sheiko (2004) considered them to be two subspecies of D. burgeri.…”

“…Because of morphological differences between the forms, including counts of dorsal-fin spines, anal-fin rays, and total vertebrae, Mecklenburg and Sheiko (2004) considered them to be two subspecies of D. burgeri. Recently, Ji and Kim (2012) described an additional species, Dictyosoma tongyeongensis Ji and Kim, 2012, from the southern coast of the Korean Peninsula.…”