Marvelous Mudflat Snails

A couple of weekends ago we enjoyed a sunny trip down island to Rathtrevor Beach Provincial Park. This BC Park is a fantastic place for kids and in the winter time the number of people using the trails and beaches are few(er) – note that on a sunny day there are still plenty of people out enjoying the park.

Rathtrevor Beach Provincial Park
The sandy mudflats at Rathtrevor Beach Provincial Park make for excellent habitat for mudflat snails and other intertidal creatures.

We parked in the subdivision that marks the boundary between park and houses. Most of the more popular BC Parks have parking meters. While I support the concept of user pay I consider not paying a passive protest against the massive funding cuts to the parks service that began nearly 10 years ago by the current Liberal government. It’s a bit of Catch-22 – I guess my thinking is that if the government is going to cut programs and services I don’t really feel like I should have to pay for the bare bones that are left. When parking fees were first imposed at provincial parks there was a noticeable drop in visitor attendance – I don’t think that it ever really recovered.

Anyhow, savouring the $3 dollars that we saved wasn’t really on our minds as we enjoyed a leisurely walk from the far side of the park on trails lined with huge old Douglas Firs. At the main beach area, the playground was a temporary distraction for Alden and Clara. It was a fairly low tide and we decided to walk out to the water’s edge.

Mudflat Snails (Batillaria attramentaria)
A pair of empty and very worn mudflat snail (Batillaria attramentaria) shells at Rathtrevor Beach Provincial Park on Vancouver Island, British Columbia.

Along the way we discovered some very cool snail shells in the sand. The mudflat snail (Batillaria attramentaria or B. cumingi) is also commonly called the screw snail because it looks a little like a screw. I found some rather worn shells in the wet mud.

Mudflat Snail (Batillaria attramentaria)
Mudflat Snails (Batillaria attramentaria) were introduced to the West Coast with Japanese Oyster spat in the early 1900s.

Mudflat snails are an introduced species that arrived, like so many exotic marine organisms, with the spat of Japanese oysters in the early 1900s. Shells can be up to 3.5 cm in length and usually marked with a beaded spiral ridge and white band that winds around the shell. Each shell has 8 to 9 whorls. The primary food of the mudflat snail is diatoms that are found on the surface of the mud. The empty shells make great homes for hermit crabs!

Mudflat Snail (Batillaria attramentaria)
Mudflat Snail (Batillaria attramentaria) shells make good homes for hermit crabs – this one was empty and waiting for a tenant.

I didn’t find any “perfect” snail shells during the short time we had on the beach but maybe that’s just as well – it’ll give me a reason to return to Rathtrevor and search for more. It was enough just to enjoy and share the fun of hunting for these interesting snails with our two small children. And besides, collecting within a provincial park is something that I just don’t do … not that there’s ever any staff around to educate visitors about the reasons why shells should be left on the beach.

If you’re interested in reading more about mudflat snails head over to Wanderin’ Weeta’s – as a Lower Mainland resident and tide pool enthusiast, she sees plenty of Batillaria on her explorations of the endless mudflats of Boundary Bay. Those interested in marveling about the microscopic can head over to Macro Monday for more closeup photography. Read more about invertebrates at Circus of the Spineless, this month hosted by Shell and Mantle.

Macro Monday
Macro Monday
Circus of the Spineless
Circus of the Spineless

5 comments

  1. Pingback: Circus of the Spineless #59! « The Shell and Mantle

  2. Many locals probably already know, but there is a healthy population of these on the inside of Goose Spit along the mud flats there – I usually walk on the outside of the spit and only recently wandered the inside and saw all the shells there. They are a really nice shape, so small and perfect.

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