Friday, June 14, 2013

Bubbles in love

On a wide, flat beach, small animals seek shelter wherever they can get it. Under the eelgrass, in burrows, on the sides of waterlogged wood, under rocks; or in populated areas, under and around human artifacts, trash, boats, anchors, bottles. One favourite hiding place is an abandoned clam shell, the bigger and more solid, the better.

At low tide, I keep an eye peeled for large shells, especially the older, seaweed-encrusted, barnacle-thickened ones. I look inside each one; no telling what I may find. Sometimes it's a scale worm or two. A couple of weeks ago, it was a collection of those little, unidentified egg casings.

Scale worm, 1 cm. long.

Egg cases. I've seen them identified recently, but can't remember where. UPDATE: Possibly the Leafy Hornmouth, Ceratostoma foliatum.

On our last visit to Boundary Bay, 'way out near the bottom of the intertidal zone, a clamshell I collected had a live bubble shell snail inside. I didn't have a container big enough for the shell, and in a plastic bag, the critter would dry out, so I walked back towards shore, carrying this clam shell half full of water. But it leaked; there must have been a crack somewhere. So at every little pool, I stopped to fill the shell again. I needed some better way to keep it wet.

When we reached another tide pool full of eelgrass, I dug out several plants, roots, a handful of sand each, and all, and stuffed it all into a plastic bag. I carefully put the clamshell and bubble snail on top, and covered it with more eelgrass, dripping wet. That should hold it.

And my last handful of eelgrass roots and sand came up with a second bubble snail. Two in a day! It went into the bag to keep the first one company.

Hammy the second, at home in a plastic cup. Love the eyes!

They both made it home ok, and made themselves at home in the tank right away. They are not like the previous one I had, a Haminoea japonica (I think); it spent most of its time in the sand. This pair wanders around on the eelgrass, and often on the glass walls of the aquarium.

Belly view, just under the water surface. With a grazing snail. (See the little pink mouth.)

These two are a native species, Haminoea vesicula, the white bubble snail. They are eating the algae off the inside of the walls, and probably off the eelgrass. When they have been knocked off onto the sand, they usually head straight for a wall and go on up. They move quite rapidly, for a snail.

Hammy the Third (aka Sir Ham), the smaller of the pair, checking out the big world above the waterline. He looks like some fat owl in a waistcoat. The round "belly" is his shell, and the flesh folds over it.

I can always find one of these if they're somewhere on a wall, because they leave a slime trail behind themselves. It catches bubbles from moving water, marking their path for several hours.

A couple of inches of slime trail, with bubbles.

I had tracked Hammy II to a spot on the front wall, and went looking for Sir Ham. I found him at the beginning of Hammy's trail, hurrying along it, staying with it, like a bloodhound on a scent. When he ran into a gap where a snail had broken the string, he cast about, up and down, until he found it again.

When I checked back, the two were together, doing what snails do in the springtime.

Hammy II above, Sir Ham below. And an intrusive periwinkle. Ignore that; the bubble shells certainly are.

They twist around some. At one point, HII was floating free, except where he held onto Sir H. Slime swirled around. This I couldn't get on camera, but towards the end, a long, thick cord dangled down below them, several inches long. When they left to go about their separate ways, it stayed behind, and gradually dissipated in the current.

And the next morning, this is what I found on the eelgrass:

Ribbon of eggs. Thousands of eggs, it seems.

This helps to identify the bubble shell; each species makes a different egg mass.

And the next day, they mated again. This morning, there is a new egg ribbon. This afternoon, they were back together. Busy little beasties. I'll be looking for eggs again tomorrow. I wonder if any will survive to grow into new little Hammies.

These snails are hermaphrodites, so both can lay eggs. I don't know who is responsible for the eggs they've laid so far.

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