title: Cosmopolitan or Cryptic Species? A Case Study of Capitella teleta (Annelida: Capitellidae).
abstract: Capitella teleta Blake et al., 2009 is an opportunistic capitellid originally described from Massachusetts (USA), but also reported from the Mediterranean, NW Atlantic, and North Pacific, including Japan. This putatively wide distribution had not been tested with DNA sequence data; intraspecific variation in morphological characters diagnostic for the species had not been assessed with specimens from non-type localities, and the species status of the Japanese population(s) was uncertain. We examined the morphology and mitochondrial COI (cytochrome c oxidase subunit I) gene sequences of Capitella specimens from two localities (Ainan and Gamo) in Japan. Specimens from Ainan and Gamo differed from C. teleta from Massachusetts in methyl-green staining pattern, shape of the genital spines, and shape of the capillary chaetae; we concluded that these characters vary intraspecifically. Species delimitation analyses of COI sequences suggested that worms from Ainan and Massachusetts represent C. teleta; these populations share a COI haplotype. The specimens from Gamo may represent a distinct species and comprise a sister group to C. teleta s. str.; we refer to the Gamo population as Capitella aff. teleta. The average Kimura 2-parameter (K2P) distance between C. teleta s. str. and C. aff. teleta was 3.7%. The COI data indicate that C. teleta actually occurs in both the NW Atlantic and NW Pacific. Given the short planktonic larval duration of C. teleta, this broad distribution may have resulted from anthropogenic dispersal.
authors.affiliation: 1 Department of Natural History Sciences, Graduate School of Science, Hokkaido University,N10 W8, Sapporo 060-0810, Japan.
authors.forename: Shinri
authors.initials: S
authors.lastname: Tomioka
authors.affiliation: 2 Laboratory of Biological Oceanography, Graduate School of Agricultural Science,Tohoku University, Sendai 981-8555, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Kondoh
authors.affiliation: 2 Laboratory of Biological Oceanography, Graduate School of Agricultural Science,Tohoku University, Sendai 981-8555, Japan.
authors.forename: Waka
authors.initials: W
authors.lastname: Sato-Okoshi
authors.affiliation: 3 National Research Institute of Fisheries and Environment of Inland Sea, FisheriesResearch Agency, Maruishi 2-17-5, Hatsukaichi 739-0452, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Ito
authors.affiliation: 1 Department of Natural History Sciences, Graduate School of Science, Hokkaido University,N10 W8, Sapporo 060-0810, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kakui
authors.affiliation: 1 Department of Natural History Sciences, Graduate School of Science, Hokkaido University,N10 W8, Sapporo 060-0810, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kajihara
mesh_terms: D000818:Animals; D000845:Annelida / Q000235:genetics* / Q000648:ultrastructure; D002140:California; D058893:DNA Barcoding, Taxonomic; D016208:Databases, Factual; D003576:Electron Transport Complex IV / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D058865:Introduced Species; D007564:Japan; D008404:Massachusetts; D010802:Phylogeny; D058974:Phylogeography; D013045:Species Specificity
chemical_list: D003576:Electron Transport Complex IV
keywords: ABGD; DNA barcoding; GMYC; PTP; TCS; annelids; invasive species; sibling species