Monday, February 23, 2009

"Endless forms ..."

"... most beautiful and wonderful ...," Darwin wrote. We looked over a small corner of that almost infinite variety on Crescent Beach last Friday.

In previous years, we have found millions (one small bay to the south of us has been estimated to hold 1.4 billion) of the invasive Asian snail, Batillaria attramentosa. That, and not much else; the native snails had been overwhelmed.

Not this year. Variety is in again. Here's a bit of what we found: (It helps to blow up the photos to full size.)

The stripy, pointed snails in the centre are Batillaria. They come in a variety of patterns and colours, from brown to grey to black and white, checkered to striped. But there, just below the pale brown invader, see that orange, curvy snail? It is one of the Nucella*, probably N. lamellosa. And over at the far left, on the clam shell, a tiny, black, globe-shaped snail could be one of the periwinkles, or maybe a young Tegula. Up on the point of the angular rock, a grey snail has longitudinal ridges. I am not sure what it is.

About Nucella. This snail boasts as many names as patterns and colours. Its colour varies from site to site; so does the pattern and even the thickness and smoothness of the shell.

This collection of Nucella comes from Port Hardy, at the northern tip of Vancouver Island. The photo is the first one from Dan Yoshimoto's page about this species; he has samples from locations up and down our coast, all different. At the bottom, he lists 21 alternate names. One of them, Thais, is the one I found in my Kozloff's "Seashore Life". (It's an older edition; maybe the name has been changed in the newer one.)

More on this snail later, in another post.

Limpets. We found two or three species of these. A couple of periwinkles, Littorina sitkana. Off to the right, an extremely indented fat snail, possibly a Tegula funebralis. Small barnacles, Balanus glandula. Assorted jelly-like organisms; green algae, blood-red algae, possibly a small patch of tar algae, and those yellow masses. (I'll deal with those in another post.)

A pair of snails, on the prowl. One green and ridged, the other black and white, much smoother. But the body, what shows of it, seems similar; licorice tentacles, with white tips, a black and white spot (Is that an eye?) at the base.

These barnacles are Chthamalus dalli. I can tell by the cross-shaped joint of the "mouth". Balanus glandula has a straight line, and another local barnacle, Balanus cariosus, has a squiggly line.

Aren't these pretty? Batillaria and a checker-board, ridged limpet. Colliselta pelta? Maybe. The barnacles are B. glandula, again.

Another pair, green and purple, although I think the green is a coating of algae. Here one is showing off the creamy body, as well as the black tentacle and eye spot.

And aren't those tiny barnacles pretty? They look almost like marzipan candies. Yum!

*I could be wrong on any of these identifications. Or most of them. To be more or less sure, I would have had to bring samples of them all home.



  1. Reminds me of a visit to Bamfield, one of the best weeks of my life. Somewhere I have a picture of four different variations of Nucella on a rock, with a cluster of eggs in the middle.
    Has anyone explained why there is so much variation in the shells of this species?

  2. Adrian, Dan Yoshimoto tackles the question on his page. Short version: nobody knows.

  3. Anonymous5:31 pm

    I just checked E-Fauna BC, and there are no photos of Batillaria attramentaria in the photo gallery there yet. It would be nice to see a few photos up there. Posts like this are interesting, they point out things worth looking into, and this species is one I'd like to know more about. Thanks for the info!

  4. HucKleberry,
    You're right. I checked, using assorted alternate names and spellings. So I have registered with E-Fauna, and will send them one of mine; I have umpteen.


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