Classification of the Columbellidae family of marine snails has always been done through the study of shells and feeding traits. But Marta deMaintenon is modernizing that system with her genetic data of the species.
By Maisie Paulson.
Based on genetic research, a professor of marine science at the University of Hawai‘i at Hilo is paving the way to discovering the evolution of a small sea snail.
Professor Marta J. deMaintenon is researching the genetic and hereditary molecular differences between different species of the family Columbellidae to understand how the family of snails evolved. She has just published a paper on her findings, Molecular phylogeny of Columbellidae (Gastropoda: Neogastropoda), (PeerJ, 2022).
It is relatively easy to recognize species of Columbellidae snails, but it’s difficult to identify individual species within that family. The study evaluates the species using DNA extraction and sequencing to clarify the relationships within this group and provide a basis for investigating the evolution of a number of characteristics that have long been of interest to marine gastropod researchers. The snails have important characteristics relative to basic marine ecology and evolution making the study even more fascinating.
From childhood interest to genetic investigations
“I have always loved seashells, and that childhood love led to a career researching the evolution and diversity of marine snails,” deMaintenon says.
When searching for a focal point in her doctoral research, she stumbled upon a number of very small and interesting snails under a rock on a beach in South Florida. As she explored more, she was fascinated with their ability to diversify evolutionarily in a short time such as their varying diets, anatomical structure similarity to larger animals, and their weird teeth (yes, snails have teeth!).
The lack of current research on their evolution drove her to conduct a study of her own. She lacked expertise and equipment at the time, so decided to team up with a friend and colleague at the Smithsonian, Ellen Strong, who serves as chair of invertebrate zoology, research zoologist, and curator of mollusks. Together they decided to embark on discovering the phylogeny (the evolutionary development and history) of Columbellidae.
The authors of the recently published paper write that the neogastropod family Columbellidae is a highly successful group of small marine snails that live on the bottom, usually crawling on or under rocks or sometimes burrowing in soft sediments. They are distributed worldwide, being most abundant in the tropics. The great diversity of the group makes them attractive for studying evolutionary shifts in gastropod anatomy, morphology, ecology, and diversity.
To begin their investigation, the research team examined recent specimens collected by Strong and other colleagues at the Natural History Museum in Paris (Muséum National d’Histoire Naturelle). In addition to specimens collected on these expeditions, deMaintenon brought her own work to the table.
“Lots of specimens are collected during expeditions, and that’s what I brought as well,” de Maintenon explains. “Each preserved snail brings a bunch of data with it: where it was collected, size, etcetera.”
From fossil records, they deduced that species of the Columbellidae family of snails may have undergone recent changes in the Caribbean and Eastern Pacific. All this happened during monumental environmental changes in the American tropics in the last five million years. This piqued their interest as a focal point where to focus their research next.
Existing classification of the family has been based to a large degree on studying snail shells and a tonguelike organ called the radula found in most mollusks for feeding. But deMaintenon and Strong have brought the study into the modern world with their dataset of nuclear genes. Their genetic findings include confirmations about traditional classification, but also point out problematic traditional classifications within the Columbellidae family. The authors conclude that their results show that the generic and subfamilial classification is in need of extensive revision and that genome data and evolutionary reconstructions are needed to resolve columbellid relationships.
“It took a few years, but the current paper helps fill out current efforts by researchers around the world studying the evolution of the huge modern diversity of marine snails,” she explains. “Now, having this paper out, we can start working on some of the more interesting details of Columbellid evolution.”
As well as making groundbreaking discoveries on snails, deMaintenon has been a part of UH Hilo faculty over the past 23 years. While advancing from associate professor to chair of the marine science department, she has received multiple awards and grants, including the Natural History Museum UK Special Funds Project award to enhance her work on Columbellidae.
Not only has her work been noted in over 15 publications, but she has been invited to present multiple times and contributed to 30 different presentations. She has been hired for contract work as well to conduct marine invertebrate identification. This work consists of identifying samples from the Keahole Point Fish farm site in Kona to monitor benthic marine life, which are bottom-dwelling creatures. deMaintenon is truly a woman of STEM!
With her investigations into the small marine snails, deMaintenon is contributing greatly to a novel area of marine science. Her genetic studies have important impacts on scientists who are developing the understanding of evolution not only for snails, but other species as well. Thirty years of studying Columbellidae and she is still completely fascinated and continues to study them.
By Maisie Paulson (B.A. in Psychology and B.A. in Administration of Justice, 2022).