It’s great to see a sea shell (mollusc), but even better to see the animal that made it, intact and getting on with its life. ‘Shell’ is a bit misleading, as many molluscs don’t have visible shells but are photogenic anyway.
I learned a lot of what I know about molluscs, both salty and fresh, from a book called The Shell Makers: Introducing Mollusks, by Alan Solem. Although it’s quite old (1974) and written by a mollusc expert who was Curator of Invertebrates at the Field Museum of Natural History, Chicago, it is far from dry. It is very detailed about the classification, structure and lifestyles of the animals themselves in all their forms (bivalves, chitons, gastropods, limpets, octopuses and their relatives, and so on, both fresh and salt water), with chapter titles like ‘To scrape a living’ (about feeding) and ‘On becoming sluggish’ (about, well, slugs). He describes the actual process of forming a shell, and there are many photos of the actual animals.
My partner-in-crime on the beach is my husband, Andrew. He’s an octopus-spotter par excellence, even when they are sheltering under their ledges in the daytime. The octopus is one of the photogenic molluscs that don’t have any shell, internal or external.
Here’s Andrew with an elephant snail, Scutus antipodes.
Here’s a close-up of Scutus antipodes.
You can often find the shell of a dead Scutus on the beach or in a rock pool.
Charonia lampas, the Australian red triton, is a common mollusc found in crevices in rock platforms around here. If you go at the lowest tides of the year (at the spring or autumn equinox), you can investigate places that are normally covered up by water.
And then there is the ringed cowry, Cypraea annulus.
Here’s something to be very careful of. Treat any live cone shell (below) with extreme caution, as some species have killed people. They sense their prey with their proboscis and eye stalks (the pair is visible below), hunt it and impale it with their harpoon. The venom paralyzes the prey, and the cone then extends its mouth to swallow it. Not all cones kill people, but enough people have been harpooned and died that you should not pick one up, and especially not put it in a trouser pocket or in your swimsuit! They are pretty, but a ‘look, don’t touch’ policy is best.
I’m looking forward to learning more about molluscs, this time land ones, when I receive my copy of The Sound of a Wild Snail Eating. This book has had great reviews.
In the meantime, to paraphrase a song, I’ll be going:
Along beaches broad and narrow
Crying cockles and mussels