Flexible colour patterns obscure identification and mimicry in Indo-Pacific Chromodoris nudibranchs (Gastropoda: Chromodorididae)

Kara K.S. Layton* (Corresponding Author), Terrence M. Gosliner, Nerida G. Wilson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


Chromodoris is a genus of colourful nudibranchs that feed on sponges and is found across the Indo-Pacific. While this was once the most diverse chromodorid genus, recent work has shown that the genus should be restricted to a monophyletic lineage that contains only 22 species, all of which exhibit black pigmentation and planar spawning behaviour. Earlier phylogenies of this group are poorly resolved and thus additional work is needed to clarify species boundaries within Chromodoris. This study presents a maximum-likelihood phylogeny based on mitochondrial loci (COI, 16S) for 345 Chromodoris specimens, including data from 323 new specimens and 22 from GenBank, from across the Indo-Pacific. Species hypotheses and phylogenetic analysis uncovered 39 taxa in total containing 18 undescribed species, with only five of 39 taxa showing stable colour patterns and distinct morphotypes. This study also presents the first evidence for regional mimicry in this genus, with C. colemani and C. joshi displaying geographically-based variation in colour patterns which appear to match locally abundant congenerics, highlighting the flexibility of these colour patterns in Chromodoris nudibranchs. The current phylogeny contains short branch lengths, polytomies and poor support at interior nodes, which is indicative of a recent radiation. As such, future work will employ a transcriptome-based exon capture approach for resolving the phylogeny of this group. In all, this study included 21 of the 22 described species in the Chromodoris sensu stricto group with broad sampling coverage from across the Indo-Pacific, constituting the most comprehensive sampling of this group to date. This work highlights several cases of undocumented diversity, ultimately expanding our knowledge of species boundaries in this group, while also demonstrating the limitations of colour patterns for species identification in this genus.
Original languageEnglish
Pages (from-to)27-36
Number of pages10
JournalMolecular Phylogenetics and Evolution
Early online date21 Feb 2018
Publication statusPublished - 31 Jul 2018

Bibliographical note

We are grateful to the many collaborators who have contributed
specimens to this work over the years, particularly to Ana Hara, Andrew K.K.S. Layton et al. Molecular Phylogenetics and Evolution 124 (2018) 27–36
34 Hosie, Clay Bryce, Corey Whisson, Daniel Geiger, David Mullins, Doris Teufel, Gary Cobb, Glenn Moore, Greg Rouse, Gustav Paulay, Julie Schubert, Justine Arnold, Karen Cheney, Kate Dawson, Lisa Kirkendale, Scott Johnson, Sue Murray, Terry Farr, and Valda Fraser. We thank Diana Prada, Gaynor Dolman, Joel Huey, Kim Lema, and Mia Hillyer at the Western Australian Museum for advice and feedback on methodology. We also thank Doris Teufel, Greg Rouse, Justine Arnold, Karen Cheney and Valda Fraser for allowing us to use their photographs in this manuscript. We also thank the Moorea Biocode Project and the Gordon and Betty Moore Foundation for providing sequence data for this2 manuscript. We thank three anonymous reviewers for their helpful revisionary suggestions on earlier versions of this manuscript. This collaborative research with key Philippine partners including: former Secretary of Agriculture Proceso J. Alcala; former Philippine Consul General Marciano Paynor and the Consular staff in San Francisco; former BFAR Director Attorney Asis G. Perez; BFAR colleagues, especially Attorney Analiza Vitug, Ludivina Labe; NFRDI colleagues especially, Director Drusila Bayate and November Romena; U.S. Embassy staff, especially Heath Bailey, Richard Bakewell and Maria Theresa N. Villa; staff of the Department of Foreign Affairs; UP administrators and colleagues including UP President Alfredo Pascual, Vice President Giselle Concepción, Dr. Annette Meñez; the staff of the National Museum of the Philippines, especially, Dr. Jeremy Barns, Anna Labrador and Marivene Manuel Santos. T.M.G also thanks Jessie de los Reyes; Marites Pastorfide; Sol Solleza; Boy Venus; Joy Napeñas; Peri Paleracio; Alexis Principe; the staff of Atlantis Dive Resort Puerto Galera, especially Gordon Strahan, Andy Pope, Marco Inocencio, Stephen Lamont, P.J Aristorenas; the staff of Lago de Oro Beach Club, Protacio Guest House; May Pagsinohin; Susan Po-Rufino; Ipat Luna; Enrique Nuñez; Jen Edrial; Anne Hazel Javier; Jay-o Castilla, Arvel Malubag; Mary Lou Salcedo, and colleagues at the Academy, friends and families. T.M.G also conveys sincere thanks to our fellow Academy and Filipino teammates on the expeditions.
Funding for this project comes from the Gorgon Project’s Barrow Island Net Conservation Benefits Fund and the University of Western Australia. K.K.S.L. is supported by a University Postgraduate Award for International Students (UPAIS) and an RTP International Fees Offset scholarship (RTPFI) administered by the University of Western Australia, as well as a postgraduate doctoral scholarship from the Natural Sciences and Engineering Research Council of Canada (NSERC). This work was also supported by a National Science Foundation grant, DEB 12576304 to T.M.G, Richard Mooi, Luis Rocha and Gary Williams inventory the biodiversity of the Verde Island Passage.


  • Chromodoris
  • Species delimitation
  • Phylogeny
  • Cryptic diversity
  • radiation
  • Mimicry


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