New California Trapdoor Spider Named for Stanislaus State Dean Martina G. Ramirez

New dune-dwelling trapdoor spider honored with dean's name

Researchers have identified a previously unrecognized trapdoor spider that lives in coastal dune habitats of California and named it Aptostichus ramirezae in honor of Martina Giselle Ramirez, dean of the College of Science at California State University, Stanislaus.

The discovery, published in October, follows DNA analyses by a team at the University of California, Davis that showed populations long treated as Aptostichus simus actually include a distinct species restricted to northern coastal dunes. The species’ range extends roughly from Moss Landing near Monterey southward toward Baja California — a surprisingly large distribution for a spider that seldom leaves its burrow.

“I was really shocked, because they kept this totally secret until the scientific paper came out in October,” Ramirez said. She added that she felt honored when she learned about the naming by email.

Ramirez’s early field work and a 1997 paper documenting dune trapdoor spiders helped raise the initial questions that led to the new study. In the late 1990s she met Jason Bond — then an undergraduate and now a professor in UC Davis’s Department of Entomology and Nematology — and mentioned her research on A. simus. Bond is the senior author of the recent paper; Emma Jochim, a UC Davis doctoral student, is the corresponding author.

Trapdoor spiders are relatives of tarantulas but much smaller. Aptostichus ramirezae is roughly the diameter of a U.S. quarter. These spiders live in silk-lined underground burrows and wait for surface vibrations before emerging to capture prey. Because individuals rarely disperse, visually similar populations can hide distinct genetic lineages — so-called cryptic species — which motivated the team’s genetic analyses.

“There are now four known species of trapdoor spiders in California that live exclusively in coastal dune habitats,” said Emma Jochim. “The one we were looking at as part of this study (Aptostichus ramirezae) was the most widespread, ranging from Moss Landing near Monterey down to Baja California — which is a pretty wide range for a trapdoor spider, given that they don’t easily leave their burrows to disperse.”

Ramirez has studied coastal dune spiders since 1981 and says habitat loss from coastal development is a major concern. “Sand dunes being at risk is a worldwide issue, so that’s what I worry about for the future: Will all these critters still be around?” she said.

The authors note that understanding which species exist in a region and how populations are genetically structured is essential to prioritize conservation efforts for vulnerable dune ecosystems.

The study’s authors include Jason Bond, Emma Jochim, Hanna R. Briggs and James Starrett of UC Davis. The research was supported by a grant from the National Science Foundation.