BishtRef
Articles Journals Publishers Authors Subjects Most Cited New Papers Year Stats Open Access
journal article Jun 25, 2025

Coastal Elites: Recurrent Trans‐Arctic Migration and Vicariance in a Cosmopolitan Sea Slug Driven by Pleistocene Glacial Cycles

Ryan A. Ellingson Julia Vo Angela Llaban Lisa M. Lugo Jann E. Vendetti Patrick J. Krug ORCID
Zoologica Scripta Vol. 54 No. 6 pp. 851-869 · Wiley
View at Publisher Save 10.1111/zsc.12738
Abstract
ABSTRACTMany coastal marine species experienced Pleistocene gene flow between the North Pacific and Atlantic. Understanding historical connectivity between ocean basins should aid in predicting how regional faunas will respond to recent warming that has intensified trans‐Arctic dispersal. Wetland fauna of the Northwestern Atlantic may have survived in estuarine refugia throughout glacial cycles, or recolonised from the southern coast, North Pacific or Northeastern Atlantic. Here, we used multilocus genetic markers and historical climate data to investigate lineage distribution and connectivity among populations of the nominally cosmopolitan sea slug Alderia modesta, sampled from mudflats on both coasts of the North Pacific and North Atlantic. Mitochondrial DNA clades from European and North American populations were deeply divergent and reciprocally monophyletic; differences at seven polymorphic nuclear loci indicated prolonged absence of trans‐Atlantic gene flow. A Pacific ancestor likely first colonised the Atlantic during the marine biotic interchange of the middle Pliocene ~3.5 Ma. Both mtDNA phylogenetics and nuclear genotype assignments support repeated trans‐Arctic colonisation of the Northwestern Atlantic from the Pacific during inter‐glacial cycles; no gene flow was evident since the last glacial maximum, however. Time‐calibrated coalescent phylogenies, Bayesian skyline plots and haplotype networks all indicated recent population expansions in the Pacific and Europe, but not Northwestern Atlantic. In both the Pacific and Northwestern Atlantic, older lineages persisted in patchy refugia north of glacial margins, while a derived clade of Pacific haplotypes indicates northward post‐LGM expansion. The biogeographical history of Alderia contrasts with rocky‐shore taxa that were largely extirpated by glacial advance and recolonised from refugia following the last glacial maximum. Based on molecular differences and distinctions in radular and penial stylet morphology, we resurrect the name Alderia harvardiensis Gould 1870 for Alderia from the Northwestern Atlantic and North Pacific; A. modesta refers exclusively to European slugs.
Topics

No keywords indexed for this article. Browse by subject →

References
84
[1]
Addison J. A. "Colonization, Dispersal, and Hybridization Influence Phylogeography of North Atlantic Sea Urchins (Strongylocentrotus droebachiensis)" Evolution (2005)
[4]
Bleakney J. S. "The Radula and Penial Stylet of Alderia modesta (Lovén, 1844) (Opisthobranchia: Ascoglossa) From Populations in North America and Europe" Veliger (1988)
[5]
Bleakney J. S. "Rediscovery of the Salt‐Marsh Sacoglossan Alderia modesta Lovén in Eastern Canada" Journal of Molluscan Studies (1967)
[9]
Caplins S. A.2022.“Genetic Basis of a Seasonal Life‐History Polyphenism.”bioRxiv 2022–09. 10.1101/2022.09.30.510344
[10]
Chen L.2025.https://www.inaturalist.org/observations/263676826.
[15]
Bayesian Phylogenetics with BEAUti and the BEAST 1.7

Alexei J. Drummond, Marc A. Suchard, Dong Xie et al.

Molecular Biology and Evolution 10.1093/molbev/mss075
[16]
Durham J. W. (1967)
[32]
Goddard J. H. R. "Range Extensions of Sacoglossan and Nudibranch Mollusks (Gastropoda: Opisthobranchia) to Alaska" Veliger (2002)
[33]
Gould A. A. (1870)
[34]
Graves D. A. "Digestive Diverticula of Alderia modesta and Elysia chlorotica (Opisthobranchia, Sacoglossa)" Veliger (1979)
[43]
Geneious Basic: An integrated and extendable desktop software platform for the organization and analysis of sequence data

Matthew Kearse, Richard Moir, Amy Wilson et al.

Bioinformatics 10.1093/bioinformatics/bts199

Showing 50 of 84 references

Metrics
1
Citations
84
References
Details
Published
Jun 25, 2025
Vol/Issue
54(6)
Pages
851-869
License
View
Authors
R
Ryan A. Ellingson

Department of Biological Sciences California State University Los Angeles California USA; Science Department Harvard‐Westlake School Studio City California USA

J
Julia Vo

Department of Biological Sciences California State University Los Angeles California USA

A
Angela Llaban

Department of Biological Sciences California State University Los Angeles California USA

L
Lisa M. Lugo

Department of Biological Sciences California State University Los Angeles California USA

J
Jann E. Vendetti

Malacology Department, Urban Nature Research Center Natural History Museum of Los Angeles County Los Angeles California USA

P
Patrick J. Krug

Department of Biological Sciences California State University Los Angeles California USA

Funding
National Science Foundation Award: DEB‐0817084
Cite This Article
Ryan A. Ellingson, Julia Vo, Angela Llaban, et al. (2025). Coastal Elites: Recurrent Trans‐Arctic Migration and Vicariance in a Cosmopolitan Sea Slug Driven by Pleistocene Glacial Cycles. Zoologica Scripta, 54(6), 851-869. https://doi.org/10.1111/zsc.12738
Related

You May Also Like

Ontogeny of the Molluscan Shell Field: a Review

ERNST KNIPRATH · 1981

108 citations

A beaked basal ornithurine bird (Aves, Ornithurae) from the Lower Cretaceous of China

Zhonghe Zhou, Fucheng Zhang · 2006

92 citations

Cladistic analysis of the fire ants of the Solenopsis saevissima species‐group (Hymenoptera: Formicidae)

James P. Pitts, Joseph V. McHugh · 2005

78 citations

Some Digenetic Trematodes of Marine Fishes from Israel's Mediterranean Coast and Their Zoogeography, Especially Those from Red Sea Immigrant Fishes

JACOB H. FISCHTHAL · 1980

63 citations

Gross morphology of multiporous plate sensilla in the Hymenoptera (Insecta)

Hasan H. Basibuyuk, Donald L. J. Quicke · 1999

62 citations