The evolutionary history of Banana Slugs (Gastropoda: Ariolimax): Native California slugs with a story to tell

$600
Raised of $500 Goal
120%
Funded on 11/23/25
Successfully Funded
  • $600
    pledged
  • 120%
    funded
  • Funded
    on 11/23/25

About This Project

The evolutionary relationships of California Banana slugs (genus Ariolimax) are unknown and unpublished. Our research asks: What are the evolutionary relationships among Ariolimax species? We hypothesize that their populations in California are distinct lineages that can be determined using DNA and morphological data. We propose 3 trips to collected specimens, with all specimens deposited at the Natural History Museum of LA County.

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What is the context of this research?

Banana slugs (Ariolimax) were described in 1859 with a revision published in 1896 that distinguished species by reproductive characters. The most recent species description, published in 1943, was also based on reproductive characters. Currently there are six described species and no published phylogeny. Banana slugs range from Santa Barbara to Sitka, Alaska and east to the Sierra foothills. Relationships between contiguous and disparate populations/species are currently unknown. Ours would be the first study to use genetic, integrated with morphological, data to determine the evolutionary relationships of these slugs. Requested funds would enable field work and specimen collection. We, as a research collaborative, will work with undergraduates in field work, specimen collection, molecular work, and analysis. Through this project and its products, people will learn about these animals and appreciate their evolutionary history in California ecosystems.



What is the significance of this project?

Though recognizable and even beloved throughout much of California, the evolutionary history and relationships of Banana slugs (genus Ariolimax) are poorly researched and still unpublished. These terrestrial gastropods constitute six described species, all of which are native to California. Their distribution is somewhat similar to the California salamander species complex/ring species, Ensatina eschscholtzii. There is even an isolated population on Palomar Mountain in San Diego County, similar perhaps to the isolation of the salamander spcies Ensatina eschscholtzii klauberi . More data from across California will give us better and more complete understanding of banana slugs and the possibility of discovering a new species, new population(s), or new introduction(s). We expect our results to be publishable and highly relevant to conservation, an improved understanding California biogeography, and mechanisms of speciation in these slugs.

What are the goals of the project?

DNA extraction and amplification have begun with specimens from the Natural History Museum of Los Angeles County and UC Santa Cruz. We had our first meeting with collaborators (9/29) and will have a plate of amplified DNA ready to be sequenced by 10/3. We plan to include CO1, 16s, 28S, and H3 genes in our phylogenetic analysis.

Upcoming research activities include three field trips (presented in this proposal), documenting slugs via iNaturalist, molecular work at the Natural History Museum of Los Angeles County, and tissue sampling of ethanol-preserved slugs at the Cal Academy of Sciences. We'll have regular Zoom meetings for collaborators and undergraduates.

In July/August 2026 we will analyze our final molecular dataset and incorporate morphological data from the slugs' radulae (toothy tongue structure) and reproductive anatomy. We will outline one or more manuscripts, perform additional analyses, and write, with a plan to submit for publication in 2027.

Budget

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All specimen will be deposited into the malacology collections of the Natural History Museum of Los Angeles County. These terrestrial gastropods constitute five described species, all native to California. Project collaborators are committed and enthusiastic; we have a grant that will cover the costs of molecular work but not all of travel and tissue collection. Some California natural history museum ethanol-preserved specimens have been subsampled with plans for more in the coming months, and morphological analysis (scanning electron microscopy) can be done at the Natural History without cost. What we lack is sufficient funding to travel and collect, which is necessary to create a robust and thorough tissue collection that represents the breadth of species diversity throughout California. Trips to sample banana slugs (lethally and non-lethal) will take place during the Winter of 2025 and Spring of 2026. We aim to publish our results in 2027.

Endorsed by

Very excited about this project! I'm sure Dr. Vendetti will do an incredible job unravelling the story of California's state land mollusk.
This is a really exciting project that promises to substantially advance our understanding of a really charismatic Californian species! Dr. Vendetti and her collaborators are the perfect team to get this project done.

Project Timeline

We hope to have 200 new banana slug tissue samples and vouchers as a product of the field trips outlined here. We anticipate having a preliminary phylogeny by January 2026, based on preserved specimens already present in collections, then an updated phylogeny based on the banana slug samples collection in late 2025 and early 2026, by May 2026. We expect to begin to write a manuscript by mid 2026. Student researchers will present research at several conferences in California.


Oct 24, 2025

Project Launched

Nov 20, 2025

Travel from Los Angeles to Santa Barbara, Santa Barbara County

Nov 22, 2025

Students present at Southern California Society of Undergraduate Research

Dec 10, 2025

Travel from Los Angeles to Palomar Mountain, San Diego County

Jan 01, 2026

Have a preliminary molecular-based phylogeny

Meet the Team

Jann Vendetti
Jann Vendetti
Associate Curator in Malacology, Natural History Museum of Los Angeles County

Affiliates

Adjunct instructor of biology at Glendale Community College (Glendale, California) & Natural History Museum of Los Angeles County
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Wallace Meyer
Wallace Meyer
Director of the Bernard Field Station and Associate Professor of Biology, Pomona College

Affiliates

Pomona College
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Crow White
Crow White
Full Professor of Biology, California Polytechnic State University, San Luis Obispo
Anna Goldman
Anna Goldman
Wildlife Museum Curator, Cal State Humboldt
Kelly Wood
Kelly Wood
Biology Instructor and Chair of the Biology Department

Affiliates

Butte Community College
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Team Bio

We aim to understand the phylogenetic relationships of banana slugs through the research mentoring of undergraduates and create the next generation of California naturalists. We are from California private and public colleges, universities, and natural history musuems. We are confident that with a robust dataset we will be able to produce a the first publishable phylogenetic hypothesis of the genus Ariolimax (Banana slugs).

Jann Vendetti

I am an Associate Curator in Malacology (Mollusks) and the Twila Bratcher Chair in Malacological Research at the Natural History Museum of Los Angeles County, and an adjunct instructor of biology at Glendale Community College (Glendale, California). My interests are in land snail systematics and their modern and historical biodiversity in Southern California and beyond. I oversee the SLIME (Snails and slugs Living in Metropolitan Environments) project on iNaturalist and use these data to understand ranges of native and introduced species. Along with a staff of collections managers, I oversee the Museum’s malacology collection of nearly 5 million specimens. I am the co-director of the Museum's Urban Nature Research Center, was the PI of an NSF-funded RaMP (Research and Mentoring for Postbaccs), have been an advisor to the Nature Conservancy’s Biodiversity Analysis in Los Angeles (BAILA) project, am a member of the UCLA La Kretz Center Postdoctoral Fellowship Search Committee. I have taught Evolution, Marine Biology, and Intro Biology at Glendale Community College, Cal Poly Pomona, and Cal State Los Angeles. I currently run an internship program jointly between the Natural History Museum of LA County and Glendale Community College. I have a B.A. from Colgate University in Biology and Geology and a Ph.D. in Integrative Biology from the University of California, Berkeley.

Wallace Meyer

Dr. Meyer is the Director of the The Claremont Colleges’ Bernard Biological Field Station, his work is also focused on the preservation and restoration of coastal sage scrub ecosystems. His research explores the fields of conservation biology, invasion biology, biogeography and ecology, including aspects of population, community and ecosystem ecology. Currently, his main research interest is in understanding how and why the species composition of local biotas are changing, and how such changes directly and indirectly affect ecosystem-level processes and properties.

Crow White

Dr. White is a marine ecologist with broad interests in molluks. His research focuses on understanding causes and consequences of spatial and temporal population dynamics of coastal marine species, trophic processes among species in communities and ecosystems, and interactions between marine ecological communities and human users of the ocean, including fisheries, renewable energy and aquaculture industries, and conservationists. .

Anna Goldman

Dr. Goldman is the curator of the Cal State Humboldt wildlife museum. She prepares, catalogs, and maintains bird and mammal specimens and exhibits for classes and research. Areas of research interests include vertebrate and invertebrate ecology, trophic interactions, and using natural history collections to further our understanding of change over time. Ultimately, she considers herself a naturalist and wants to inspire students' curiosity with the natural world. In addition, she is the primary contact person for Humboldt County for the Marine Wildlife Care Center within the Oiled Wildlife Care Network along the California coast. She is broadly interested in the natural history of California, including banana slugs.

Kelly Wood

Professor Wood is an instructor primarily teaching Physiology courses but has also taught Anatomy, Zoology, General Biology, and Bioinformatics. She is also an advisor to a student club called Friends of the Refuge where we actively work on our 928-acre wildlife refuge on projects to identify species, educate the public, and restore the natural campus.


Project Backers

  • 3Backers
  • 120%Funded
  • $600Total Donations
  • $200.00Average Donation
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