TY - JOUR

T1 - A tale of two soft-shell clams

T2 - An integrative taxonomic analysis confirms Mya japonica as a valid species distinct from Mya arenaria (Bivalvia: Myidae)

AU - Zhang, Junlong

AU - Yurchenko, Olga V.

AU - Lutaenko, Konstantin A.

AU - Kalachev, Alexander V.

AU - Nekhaev, Ivan O.

AU - Aguilar, Robert

AU - Zhan, Zifeng

AU - Ogburn, Matthew B.

N1 - Funding Information: This study was supported by the Special Funds for the Young Scholars of Taxonomy of the Chinese Funding Information: This study was supported by the Special Funds for the Young Scholars of Taxonomy of the Chinese Academy of Sciences (No. ZSBR-009), the Bureau of International Cooperation Chinese Academy of Sciences, the Far Eastern Branch of the Russian Academy of Sciences (No. 15-I-6–007 o) and the Russian Foundation for Basic Research (No. RFFI-ofi 15-29-0245615). The authors are grateful to Amy Driskell (Smithsonian Laboratories of Analytical Biology) for sequencing the Chesapeake Bay Mya arenaria samples. We thank Prof. Jim Carlton (Williams College, USA) for helpful suggestions on the manuscript. Irina E. Volvenko (Zoological Museum, Far Eastern Federal University, Russia) kindly took photographs of shells. Publisher Copyright: © 2018 The Linnean Society of London. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2018/10/20

Y1 - 2018/10/20

N2 - The soft-shell clam Mya arenaria Linnaeus, 1758 is a commercially important fishery resource that occurs in boreal and temperate environments in the Northern Hemisphere. Whether the soft-shell clam is a single species with a circumboreal range or a species complex also comprising Mya japonica Jay, 1857 distributed in the north Pacific has long been debated by malacologists and palaeontologists based on slight differences in shell morphology. We used an integrative taxonomic approach incorporating available Mya spp. mitochondrial COI and 16S rRNA, and nuclear 28S rRNA gene sequences, as well as spermatozoan and shell morphological characters to test the validity of M. japonica and examine the range of soft-shell clam distribution. Although differences in shell morphology were minor, the results from tree topologies, pairwise uncorrected p-distances, Automatic Barcode Gap Discovery (ABGD) and spermatozoan ultramorphological data confirm the validity of M. japonica in both its endemic region in the northwest Pacific, and as here newly reported introduced populations in British Columbia in the northeast Pacific, and show that M. arenaria is distributed in the northeast Pacific, North Atlantic, Barents Sea (Arctic Ocean) and Mediterranean. We estimate these two closely related sister species diverged 4.1–12.5 Myr during early Pliocene to late Miocene, which is consistent with current evolutionary theory regarding M. arenaria. In addition, ABGD indicated the congener Mya truncata Linnaeus, 1758 may represent a species complex, but additional evidence is still needed to clarify its taxonomic status.

AB - The soft-shell clam Mya arenaria Linnaeus, 1758 is a commercially important fishery resource that occurs in boreal and temperate environments in the Northern Hemisphere. Whether the soft-shell clam is a single species with a circumboreal range or a species complex also comprising Mya japonica Jay, 1857 distributed in the north Pacific has long been debated by malacologists and palaeontologists based on slight differences in shell morphology. We used an integrative taxonomic approach incorporating available Mya spp. mitochondrial COI and 16S rRNA, and nuclear 28S rRNA gene sequences, as well as spermatozoan and shell morphological characters to test the validity of M. japonica and examine the range of soft-shell clam distribution. Although differences in shell morphology were minor, the results from tree topologies, pairwise uncorrected p-distances, Automatic Barcode Gap Discovery (ABGD) and spermatozoan ultramorphological data confirm the validity of M. japonica in both its endemic region in the northwest Pacific, and as here newly reported introduced populations in British Columbia in the northeast Pacific, and show that M. arenaria is distributed in the northeast Pacific, North Atlantic, Barents Sea (Arctic Ocean) and Mediterranean. We estimate these two closely related sister species diverged 4.1–12.5 Myr during early Pliocene to late Miocene, which is consistent with current evolutionary theory regarding M. arenaria. In addition, ABGD indicated the congener Mya truncata Linnaeus, 1758 may represent a species complex, but additional evidence is still needed to clarify its taxonomic status.

KW - Biogeography

KW - Cryptic species

KW - DNA barcoding

KW - Molecular phylogeny

KW - Mollusca

KW - Spermatozoan ultramorphology

UR - http://www.scopus.com/inward/record.url?scp=85053474880&partnerID=8YFLogxK

U2 - 10.1093/zoolinnean/zlx107

DO - 10.1093/zoolinnean/zlx107

M3 - Article

AN - SCOPUS:85053474880

VL - 184

SP - 605

EP - 622

JO - Zoological Journal of the Linnean Society

JF - Zoological Journal of the Linnean Society

SN - 0024-4082

IS - 3

ER -