Occurrence of Orthione griffenismarkham, 2004 (Isopoda: Bopyridae), parasite of the mud shrimp upogebia major(de Haan, 1841) in South Korean waters, and its implications with respect to marine bioinvasion

Abstract

In recent years, extensive populations of burrowing mud shrimp have suddenly invaded the tidal flats in South Korea where clams, Ruditapes philippinarum, are harvested. These shrimp pose a serious threat to the clam industry along the west coast of South Korea. While conducting a mud shrimp monitoring program, we collected six female/male pairs of a pseudionine bopyrid isopod, Orthione griffenisMarkham, 2004, which in North America has been considered an introduced species from Asia that threatens northeastern Pacific estuarine ecosystems. We report the occurrence of this isopod as an inhabitant of the branchial chambers of the host shrimp, Upogebia major(de Haan, 1841), a very common species along the South Korean west coast, along with a morphological description and phylogenetic analysis based on COI barcodes. DNA analysis supported strongly that South Korean Orthioneis the same species of western Pacific (USA), O. griffenis. Two regionally disjunct isopods showed very low (0.8%) genetic variation in the mitochondrial COI (cytochrome oxidase subunit I) sequences. The implications of the occurrence of this species with respect to marine bioinvasion are also discussed.