Stowaway

I had forgotten about a snail shell in my pocket. Snapped into a plastic vial yesterday and brought home to be photographed—let this laggard, my forgetfulness, fill in for today’s observation, I thought, especially as the weather had turned cold and rainy. As I tipped the shell from the vial a tiny black speck moved on the outside of the shell. It was so small I couldn’t tell what it was. Appearing to fly from place to place, my first guess was a small fly or wasp. But then I noticed the splayed legs and recognized it as a spider, a minum member of the Salticidae, a jumper.

First, though, I set about documenting the snail shell. The spiral is not maintained for long, just one or two twists and the shell widens majestically, the tight beginnings a small knot opposite the large fragile globe. There are a number of land snails that look like this spread across several genera but all given the common name of Ambersnail because of their translucent, amber-colored shells. The shell is very thin, fragile as baked phyllo dough, and already some of the rim of the aperture has crumbled away.

After documenting the shell, attention turned to the stowaway. Because of its small size, I added an extension tube to the macro lens on the camera, gaining some magnification, giving away some depth-of-field. Now the spider could be viewed quite clearly, even the eyes, and jumping spiders have astonishing eyes. I always get the impression that they must be inquisitive creatures, especially when they look in your direction, huge eyes wide open. Their look is one of perpetual astonishment, philosophers or explorers, the poets of the spider world. (And, somewhat fittingly, this tiny jumping spider escaped in the vicinity of my typewriter.)

Jumpers often retreat at night and in cool weather to silk shelters in hidden places, in this instance the spider ensconced itself inside an empty shell. Spiders will use other hollow objects as well, empty seed pods, folded and curled leaves, even the cast off skins left behind by emerging dragonflies get co-opted as temporary dwellings.

Since we’re on the subject of interesting spider feats, I recently learned of a species of spider in Madagascar that commandeers empty snail shells and, instead of simply occupying them, the spider hoists them off the ground to an overhanging branch by using its silk as a kind of block and tackle, creating a suspended abode that looks something like an ornament hanging from a Christmas tree branch.

Posted on March 30, 2017 02:47 AM by