Phylogeography and genetic diversity of the Japanese mud shrimp Upogebia major (Crustacea, Decapoda, Upogebiidae): Natural or anthropogenic dispersal?

Abstract

Upogebia major (De Haan, 1841) is known for forming huge burrows in sandy, intertidal areas that can extend to depths of over 2 m. Despite its widespread distribution in East Asia and Russia, the genetic relatedness of its regional populations remains uncertain, likely owing to difficulties in specimen collection. Therefore, to appraise the phylogeographic patterns, genetic diversity, and morphological variety of U. major, the mitochondrial DNA of specimens collected from Japan, Korea and China were subjected to molecular phylogenetic analyses of COI genes, alongside morphological assessment. As a result, we discovered four principal groups; of these, Group 1 consisted predominantly of Japanese specimens, while Groups 3 and 4 were interpreted as having originated from the continent. Group 2 exhibited genetic segregation from both continental and Japanese descent. Group 1 mostly comprising Japanese specimens implies that the planktonic larvae of U. major were disseminated north and south by ocean currents encompassing the Japanese archipelago. In contrast, individuals probably originating from the continent were discovered in Lake Notoro, Hokkaido and Matsukawa-ura, Fukushima in northeastern Japan, indicating possible introduction from the continent through ocean currents or unintentional introduction with other organisms imported. Additionally, one of the specimens collected from Matsukawa-ura exhibited significant genetic and morphological differences from other specimens, suggesting the possibility of being a subspecies. The outcomes of this study not only offer valuable insights into the origins of distribution of U. major but also introduce a novel challenge of assessing the coexistence of two routes: natural and anthropogenic dispersion.

Characterization of polychaetes inhabiting estuaries and inner bays by composition analysis of amino acids and lactate enantiomers

“…Setojima Island is located in the inner region of the bay with bottom sediment comprising soft mud. Various organisms, including polychaetes such as Marphysa sp, an asari clam Ruditapes philippinarum , and the Japanese mud shrimp Upogebia major 18 inhabit these sites. Although the collection sites along the coast of Tokyo Bay are located around rivers and estuaries, the artificial tidal flat and Setojima Island is located on the Mangoku-ura Lagoon.…”

Population Characteristics of the Mud Shrimp Upogebia major (De Haan, 1841) (Decapoda: Gebiidea: Upogebiidae) on Korean Tidal Flats in the Eastern Yellow Sea

“…This species constructs extensive Y-shaped burrows below the sediment surface and often occurs in very high densities [2,3] in intertidal sandy mudflats, with observed depths reaching over 2.08 m [2]. It is commonly found along the coasts of Korea, Japan, China, and Russia [4][5][6][7][8][9]. They are considered among the most influential ecosystem engineers in marine soft-bottom ecosystems [6,[10][11][12][13].…”