Some of the highlights of our gastropod crawl in Central Park on Monday and Tuesday: Helisoma trivolvis, called the Ramshorn or Three-whorled Rams Horn, a fresh-water species fished out of the Meer. This specimen, the only one found, was 1/2″ or 14mm long.The ground was quite dry, so we knew that land snails would be a challenge to find. They like moisture and the night; the sun is their enemy. But we did see numerous Oxychilus cellarius, the Common Cellar Snail, under damp wood. This is a species that favors human habitation, as its names suggest. Originally from Europe, these are quite small: the largest was 8mm, most were around 5mm. Note the translucent shell when the animal, a glistening blue-gray, is fully extended outside. Here’s another look at these hard-to-photograph critters:
Also clinging to the dampness of old pieces of wood were the slugs, hiding out from the day:Limax maximus, the Leopard slug, another European import. I’ve seen them up to four inches long, which goes towards another of their common names, the Giant Garden Slug. One fearless student had one wrapped around her finger. Ok, it was a latex-gloved finger, but still, she and everybody else thought it was pretty damn fascinating, tentacle eyes advancing, breathing hole visible.Another slug, Arion subfuscus, which are reputed to taste absolutely terrible. About an inch long here, but all the slugs, and snails, are remarkably stretchy creatures. Slugs can contact to a sixth of their full length; if I could do this I’d be down to about a foot high in my boots.
Gastropods, you will no doubt remember, are a class within the phylum Mollusca, which is named after the Latin word for the “soft things.” What? Well, this stylized octopus — another mollusk — meets Utamaro-inspired ukiyo/manga paste-up was not found in Central Park, but at the end of the day on Smith Street.