Present or Absent: Parasites in Marine Snails

By: Racine Rangel

Hello all! My name is Racine Rangel, and I am a third year PhD student working with Cascade Sorte at the University of California, Irvine (UCI). Our lab investigates the impacts of global change on marine coastal communities over large geographic ranges using integrative approaches including physiology, ecology, and biology.

Enjoying a morning hike with Bird Rock in the distance

Enjoying a morning hike with Bird Rock in the distance

Before this summer, I visited Catalina for a few other research adventures. I first landed on Catalina during my master’s degree at California State University Long Beach (CSULB) where I was studying the physiology of the brightly colored, Blue-banded goby! If you take a snorkel around Big Fisherman’s Cove, you’ll see them darting all over the rocky reefs. After graduating from CSULB I started my Ph.D. program at UCI where I left Southern California and headed north to a different island, Sitka, Alaska. While in Sitka, one of the key things I was told to look for in my marine snails were trematode parasites. However, I never found any parasites at my study sites and so after finishing my Sitka projects I wanted to look closer to home for parasites in snails.

A view of Wrigley and the ocean

A view of Wrigley and the ocean

So out at Catalina, I investigated how changing climate conditions may impact the relationship between the Eroded Periwinkle snail (Littorina keenae) and their trematode parasites. I was also studying the importance of conservation areas, such as Marine Protected Areas (MPAs) and how they might be able to buffer new parasite invasions. You might be wondering HOW snails get these parasites, and one way in which marine snails get parasitized is from birds and lots and lots of bird poop! Lucky for me, right next to Wrigley is the best place I could think of to look for parasites, Bird Rock. This rock is a favorite among many different types of shorebirds, like brown pelicans, cormorants, sea gulls, and even a couple black oystercatchers.

An early morning collection at Little Harbor

An early morning collection at Little Harbor

Working at Wrigley allowed me to investigate what the parasite prevalence may be on the island in different MPAs. I surveyed two sites, including Bird Rock and Little Harbor, and collected approximately 400 snails. After viewing them each under a microscope, surprisingly, I found no parasites! This means the Catalina snails are relatively healthy. I’ll continue looking around the mainland for any areas that have snails with parasites.

Photo on left: A close-up of L. keenae. Photo on right: Snails in individual containers before being viewed under a microscope for parasites

Photo on left: A close-up of L. keenae. Photo on right: Snails in individual containers before being viewed under a microscope for parasites

I am so happy I was able to carry out my research at Wrigley and survey the island. Despite not finding any parasites, it only opens more exciting questions about where they could be! I am very grateful for the Wrigley staff in helping me get out to the island and conduct my research.