Posts Tagged 'snails'



Three for Thanksgiving

A trio of things found in a southeastern New Hampshire garden this summer by our Thanksgiving dinner host.

Burying beetle, Nicrophorus orbicollis. Gray lancetooth snail, Haplotrema concavum (I think). Six-spotted tiger beetle, Cicindela sexguttata.

Let’s take a closer look at the latter:The elytra are parted to reveal the underwings.

Back 40 Snail

A snail in the Back 40, hunkered down on the fence. Invasive Cepaea nemoralis, no stranger here. Showed up on Friday. Some mucous glue holds this onto the vertical surface, the animal withdrawn deep into the whorls of the shell.

Stomach-foot

Snails are members of the class Gastropoda, a term derived from Greek words for stomach and foot, based on the mistaken belief that their foot is also their stomach. In fact their guts are usually located in that part of the snail that stays inside its shell. Here’s what it looks like from the earth’s eye view. This did not retract into its shell, as many snails will. The slime trail this left on the garden rocks was a faint slivery blue.

Calvert Vaux Park

Calvert Vaux was born in London (the family name rhymes with “fox”), immigrated to America, worked with Andrew Jackson Dowling, the founding father of American landscape architecture, and published Villas and Cottages, a landmark of American neo-Gothic design. Vaux’s great claim to fame, however, is teaming up with Frederick Law Olmsted to work on both Central and Prospect Parks. The two men had a famously testy relationship, but the glory of their parks is testament to their clash of prickly genius. Olmsted, who wrote a lot and had a son/step-son carry his name well into the 20th century, long overshadowed Vaux (there was a benighted time when Olmsted got sole credit for the parks). Both men had sad ends, Olmsted sinking into senility, Vaux drowning in Gravesend Bay in 1895. It seems that one day he took a walk and never came back. It was rather mysterious. His body washed ashore along the south coast of the borough. Some belated recognition has come in the renaming of Dreier-Offerman Park in Bensonhurst for him. (The park had been named for a home for unwed mothers; some of the land cobbled together for the park had been used for landfill from construction of the Verrazano Narrows Bridge.) Half-sunk barges and the famous yellow submarine clog the inlet between the southern and northern parts of the park. The inlet in particular becomes muddy flat at low tide, making it rich bird habitat (I saw a guy crabbing there once, too); and the park as a whole is an important first stop for migrating birds coming up from the south. A good chunk of the park is currently fenced off, part of the sports-facilities-heavy re-design. The “contaminated soil removal” signs are a reminder of how the area was long treated. The park is not particularly pedestrian-friendly, being between the water and the infernal Belt Parkway. But we managed to infiltrate anyway, walking from Stillwell Avenue in Coney Island. The other nearby subway stop is the D train at 25th Avenue/86th St., with a pedestrian bridge crossing the highway at 27th Ave. Actually, there is a bumpy road in, but we went down Bay 44th Street, crossed a tire-filled gully (as we were eyed by big feral cats), and went through a hole in the baseball field fence that some earlier commandos had snipped. A juvenile red-shouldered hawk — which has been reported hanging around the park for a while now, rather unusual for the borough — on the fence, and two killdeer on the field greeted us along with the usual Canada and brant geese. South of the active baseball fields, we found a surprising expanse of flat land bordering Coney Island Creek, which was still full of geese, ducks, and gulls. Only other other person was about, mysteriously emerging from the reeds with his bicycle (he, no doubt, wondered about us with our bins and rooting around for snail shells). The views of the Narrows were superlative. In the winter-squashed grasses along the shore we found a huge number of land snail shells. These are Cepaea nemoralis, which is also known as the brown-lipped or English garden snail. Note that the three smaller snails at the bottom all have umbilicuses, navel-like holes, which I thought would mean they are another species. After consulting with a specialist, Aydin Orstan of the excellent Snail Tales blog, I learned that juvenile C. nemoralis have open umbilicuses, and the occasional adult will too.

Virgin Gorda Beachcombing

Various intertidal snails were found on old coral, mangrove roots, rocks, coconut shells.

All Creatures Great and Small

Mostly small. And mostly slimy (cue Monty Python).

More tidying up in the Back 40 in preparation for winter. My backyard is a Brutalist expanse of poured concrete, so I use numerous pots for planters. All were salvaged from the street. There’s also a found-on-the-sidewalk wooden box, festively decorated with painted balloons. While moving this the other day, I found these creatures beneath it. Generally shunned by the dainty among us, these creatures of the shady damp — slug, snail, pillbug — are key to decomposition and recycling nutrients, and thus making the world go ’round and ’round. An earthworm, three more of the disk snails pictured in a previous post, a centipede, some smaller pillbugs, and several way-too-small-to-figure-out things were under there as well.
A closer look at the Common pillbug, Armadillidium vulgare, also known as common woodlouse or roly-poly. When disturbed or otherwise bummed out, these roll up into a tight armored ball. Love the overlapping plates here. These are not insects, btw; they’re crustaceans.
I find this land snail strangely beautiful: the contrast of amber shell and blue grey gastropod itself. The shell is about 1/4th-inch across, so bigger than the disks, and much smoother. The umbilicus, which is on the other side of the shell, is very deep (like Jimmy Joyce’s Omphalos). I think it’s a member of the family of glass snails, Oxychilidae. It looks like it might be Oxychilus draparnaldi, but they are supposed to be rather larger, so I’m not sure.

“We must not feel a childish disgust at the investigations of the meaner animals. For there is something marvelous in all natural things.” — Aristotle

Tiny disk


Tidying up the Back 40 (inches) this time of year inevitably unearths some signs of life settling in for the winter. This is one of several very small disk snails I’ve found attached to brick or metal outside. I’ve seen these critters before and think they are probably Discus rotundatus, immigrants from Europe like many another Brooklynite.

They’re small, about 3/16ths inch across. As such, they present a photographic challenge. I bought one in to try another series of shots, and the snail itself emerged to see what the hell was going on.

This one was returned to the Back 40.

Aren’t those shells amazing?

Vocabulary builder: Estivation, or aestivation, a form of summer-time hibernation, from the Latin word for summer. In hot, dry seasons, some land snails will pull themselves into their shells and chill out for a while, awaiting the days of greater moisture. They seal their shells with a membrane of dried mucus, or a calcium carbonate-reinforced barrier called an epiphragm. For winter, they can also tuck in, close down, seal up, and nestle under some kind of shelter to survive the cold. Not so different, really, from some people I know….

More snails


I found this little specimen in North Andover, MA. I think it’s Oxyloma retusum, the blunt ambersnail.

This is a fairly similar animal, but I’m not sure it’s the same species since the shell is not glossy or amber. What do you think? I found this one on Nantucket, MA. Is that snail turd there?
Meanwhile, this is an operculum. It’s the door, essentially, to a snail, attached to the bottom of the foot so that when the snail draws inside the shell, it can seal itself in. Not all snails have these, but the mystery snails of Green-Wood Cemetery do. Something scarfs these snails up around the edges of the Valley Water, but the predator does not like the thin shells, which are usually shattered. A couple of these operculum were recently lying around as well. I still think these are Cipangopaludina chinensis, formerly known as Viviparus malleatus, but I’m happy to be schooled if I’m wrong.

Snail Tales, part III

For a change of pace, a fresh water gastropod, which means I did not find these in the Back 40. The species is a Brooklyn resident, however: I took this photo at the Valley Water in Green-Wood. I think the snail is Viviparus malleatus, the Chinese mystery snail, a.k.a. the Japanese trapdoor snail. (Like many of us, these come from somewhere else.) What you see above is, I think, only half the size of the shell of the living creature. I was lucky to find this much. Mostly, it’s all shards. The pond’s stone edge is littered with broken shells. Something eats these critters like no tomorrow. The shell is particularly thin, so it seems to be easy to crack, spear, smash.

Snail tales, part II

They leave a trail of slime and eat your plants, or at least some of them do, but gastropods, with their shells, love darts (!), and hermaphroditism, are as remarkable as any other life-form. (Until you’ve seen slugs mating, my friend, you have not lived. A future post will get sluggy. )
Last autumn, while cleaning up the Back 40 in preparation for winter, I found this snail underneath one of my pots. It’s posing on a glass topped table. 3/8ths inch long shell, with a deep umbilicus. I’m not sure what species it is.

This stripped specimen was also found in the Back 40.

Here it is surrounded by other examples of its species, Cepaea nemoralis, the rest of which were found at Dead Horse Bay or Jamaica Bay or here or there. The species is obviously pretty polymorphic in coloration, but all have the brown lip that gives them one of their common names, the brown-lipped snail. Except for that one on the unfocused right, which isn’t like the others:
This one I’m also not sure of. It doesn’t have a brown lip but definitely does have an umbilicus, which C. nemoralis lacks. (D’uh! and I also don’t remember where I found it.) Oh, well, it’s here for comparing and contrasting.

To recap: the unknown species in the first image above; the C. lubrica in the previous post; the stripped C. nemoralis; and the tiny D. rotundatus that I found last month, make for four different species of snail in the Back 40.


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