I have found four of these snail shells on Bodega Head since 2005, so here are two more examples. These individuals are ~9 mm long:
And here are the same individuals from below:
These are California Cone Snails (Californiconus californicus, formerly Conus californicus).
Although there are many species of cone snails throughout the world (>500), this is the only species of cone snail found in California.
The northern range limit for this species is often listed as the Farallon Islands. So when I first found one in Bodega Bay, I was excited to think about the possibility of documenting a new northern record.
But when I asked Jim about about whether any cone snails had been found in Bodega Bay before, he recalled two different observations — (1) In the 1970s, Cadet Hand, founding director of the Bodega Marine Lab, told Jim that cone snails washed ashore on Bodega Head "very rarely"; and (2) there are two cone snail specimens from Jenner (collected in the 1950s) in the California Academy of Sciences collection.
So my specimens aren't the first from north of the Farallon Islands, but cone snails are a rare find in this area. It was fun for me to find out that Cadet Hand is one of the few other observers to have documented cone snails on Bodega Head. The Bodega Marine Lab is celebrating its 50th anniversary this year (Happy Anniversary!), so I've been thinking about Cadet...and that led me to think about cone snails.
If you aren't familiar with cone snails, their feeding behavior is fascinating. They have specialized "teeth" shaped like harpoons with which they can inject venom into their prey:
From Kohn et al. 1999. Snail spears and scimitars: A character analysis of Conus radular teeth. J. Molluscan Studies 65: 461-481.
In case you're wondering, California Cone Snail prey includes fish, molluscs, polychaete worms, and crustaceans.
Although the individuals shown above are small, California Cone Snails can reach lengths of ~35 mm (~1.3 inches), so keep an eye out for these intriguing snails. Perhaps you'll document them at a site that's even further north than Bodega Bay!