Life history, patchy distribution, and patchy taxonomy in a shallow- water invertebrate (Mollusca Polyplacophora: Lepidopleurida) Sigwart, J. D., & Chen, C. (2017). Life history, patchy distribution, and patchy taxonomy in a shallow-water invertebrate (Mollusca Polyplacophora: Lepidopleurida). Marine Biodiversity. https://doi.org/10.1007/s12526- 017-0688-1 Published in: Marine Biodiversity Document Version: Publisher's PDF, also known as Version of record Queen's University Belfast - Research Portal: Link to publication record in Queen's University Belfast Research Portal Publisher rights © 2017 The Authors. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made General rights Copyright for the publications made accessible via the Queen's University Belfast Research Portal is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy The Research Portal is Queen's institutional repository that provides access to Queen's research output. Every effort has been made to ensure that content in the Research Portal does not infringe any person's rights, or applicable UK laws. If you discover content in the Research Portal that you believe breaches copyright or violates any law, please contact [email protected]. Download date:08. Oct. 2021 Life history, patchy distribution, and patchy taxonomy in a shallow- water invertebrate (Mollusca Polyplacophora: Lepidopleurida) Sigwart, J. D., & Chen, C. (2017). Life history, patchy distribution, and patchy taxonomy in a shallow-water invertebrate (Mollusca Polyplacophora: Lepidopleurida). Marine Biodiversity. https://doi.org/10.1007/s12526- 017-0688-1 Published in: Marine Biodiversity Document Version: Publisher's PDF, also known as Version of record Queen's University Belfast - Research Portal: Link to publication record in Queen's University Belfast Research Portal Publisher rights © 2017 The Authors. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made General rights Copyright for the publications made accessible via the Queen's University Belfast Research Portal is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy The Research Portal is Queen's institutional repository that provides access to Queen's research output. Every effort has been made to ensure that content in the Research Portal does not infringe any person's rights, or applicable UK laws. If you discover content in the Research Portal that you believe breaches copyright or violates any law, please contact [email protected]. Download date:10. Mar. 2019 This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No H2020-MSCA- IF-2014-655661. Mar Biodiv (2018) 48:1867–1877 DOI 10.1007/s12526-017-0688-1 ORIGINAL PAPER Life history, patchy distribution, and patchy taxonomy in a shallow-water invertebrate (Mollusca: Polyplacophora: Lepidopleurida) Julia D. Sigwart1,2 & Chong Chen3 Received: 15 February 2016 /Revised: 7 March 2017 /Accepted: 19 March 2017 /Published online: 8 April 2017 # The Author(s) 2017. This article is published with open access at Springerlink.com Abstract Things without names are difficult to rationalise, for L. rugatus s.l. revealed four discrete clusters which cor- and so species that go without names are difficult to con- respond to different parts of the geographic range. We infer serve or protect. This is a case study in resolving conflicts in these to represent four distinct species, at least two of which historical taxonomy and ‘real’ species (identifiable and evo- are likely novel. Leptochiton rugatus sensu stricto is herein lutionarily relevant groupings) using an approach including reinterpreted as restricted to California and Baja California, population genetics, natural history, and pragmatism. We and the new name L. cascadiensis sp. nov. is established for report the observation that populations of a shallow-water the lineage with a distribution in the Cascadia coastal biore- chiton species from Washington and British Columbia dem- gion from the panhandle of Alaska to Oregon. There are onstrate extremely high site fidelity and patchy distribution. minor morphological differences among these species in Their limited dispersal potential and isolation could be ex- the L. rugatus species complex, but genetic data or morpho- plained by a brooding life history. This stands in direct con- logical observations alone would not have been sufficient to trast with the supposedly wide distribution of this “species”, definitively recognise these groups as species-level lineages. Leptochiton rugatus (Carpenter in Pilsbry, 1892) sensu lato, The observation that different species within the complex from the Sea of Japan to Baja California. But this lineage may have different life history strategies provides important has previously been suggested to comprise several cryptic support for interpreting different populations as genuinely species. Indeed, a haplotype network analysis using 61 indi- separate species. vidual sequences of the cytochrome oxidase c subunit I gene Keywords Chiton . Cryptic species . Haplotype network . Life history . Northeast Pacific Communicated by V. Urgorri Introduction This article is registered in ZooBank under urn:lsid:zoobank.org: pub:A5CD7021-089C-4494-B0CA-875FB64F72ED Genetic information has repeatedly revealed higher levels of * Julia D. Sigwart first-order diversity than traditional morphological assessment. [email protected] In most cases, genetic differences prompt a re-examination of previously overlooked morphological variation, which reveals “pseudocryptic” assemblages differentiated by these emergent 1 Marine Laboratory, Queen’s University Belfast, 12-13 The Strand, Portaferry, Northern Ireland features (Knowlton 1993). But molecular evidence, like some morphological evidence, may not be sufficient in isolation to 2 Museum of Paleontology, University of California, Berkeley, VLSB 1101, Berkeley, CA 94720, USA make a taxonomic determination, especially when dealing with one gene region or one character (Riedel et al. 2013). 3 Department of Subsurface Geobiological Analysis and Research (D-SUGAR), Japan Agency for Marine-Earth Science and Overlooked differences are found to correlate with historical Technology (JAMSTEC), 2-15 Natsushima-cho, hypotheses about species, representing additional taxonomic Yokosuka, Kanagawa 237-0061, Japan names that have been consigned to obscurity as junior 1868 Mar Biodiv (2018) 48:1867–1877 synonyms. These synonymies have been flagged as a key bot- British Columbia, adjacent to a specific prominent intertidal tleneck in quantifying global species richness (Costello et al. boulder, has been home to a population continuously since at 2013a), a problem that needs to be addressed through concerted least 1986 (JDS, pers. obs. and museum records, last observa- efforts by taxonomic experts. It is presently unclear to what tion 2013). Field observations herein were recorded from spec- extent the number of available names in synonymy balances imens collected on 17 July 2012 from a population in False the number of global marine species left undescribed. Bay, San Juan Island, Washington, USA (48.57°N 123.17°E). Polyplacophoran molluscs (chitons) have a reputation as a To examine the potential genetic differences among the taxonomically “difficult” group. In particular, the genus Leptochiton aff. “rugatus” species complex, we assem- Leptochiton GRAY, 1847 is well known to be paraphyletic; bled all available published COI sequences attributed to although key features clearly separate more than 120 accepted Leptochiton rugatus sensu lato and species that resolved living species, no characters have been identified that can be within the L. rugatus clade in previous analyses (Sigwart used to diagnose supraspecific groups (Sigwart et al. 2011). et al. 2011;Sigwart2016), and added sequences from two Many species of the genus Leptochiton are known from deep- intermediate populations in Washington and Oregon, sea habitats, but several species are known from shallow wa- USA. These 61 sequences (Table 1) represent specimens ter, including the North Pacific Leptochiton rugatus from Russia, Alaska, British Columbia, Washington, (Carpenter in Pilsbry, 1892). This species (complex) ranges Oregon, California, and Mexico. We used TCS version from the Sea of Japan across to Alaska, down the coast of 1.21 software (Clement et al. 2000) to reconstruct statis- NorthAmericantoBajaCalifornia(KaasandVanBelle tical parsimony haplotype networks from a 362-bp align- 1985). It is anecdotally