Thursday, April 10, 2014

The lettuce eaters

Winter in the intertidal zone is difficult, even here where it barely gets cold. The water is often turbulent, the nights are long, the daylight dim. The plants and algae, the seaweeds and eelgrasses, die back, leaving no shelter from the flocking thousands of sandpipers foraging in the shallows.

We see little more than worm tubes and holes, snails, those everlasting invasive Asian mud snails mostly, and the hermit crabs that use their abandoned shells, fewer hermits than we would see in warmer weather. Many don't make it through to spring.

My tank residents have it easy. The temperature stays the same year-round. The current rarely changes, except when I'm cleaning the pump. There is daylight 16 hours a day, always bright, never clouded over. And there are no birds. No birds!

The one small bump in this easy road is the intermittent supply of greens. Often, on a trip to the beach, I manage to bring back only a few handfuls of skimpy eelgrass and a bit of half-dead kelp. It's rare that I find sea lettuce for them in the winter, or Turkish towel that isn't all torn and rotting. Sometimes their tank is almost empty of vegetation; when I then bring the hermits a mess of hydroid-covered eelgrass, they climb on it and never leave until it's bare.

This winter has been exceptionally hard for them; they have been getting a small taste of what their cousins on the beach go through every year. What with one thing and another, the weather, and the state of our health, and other time constraints, we haven't been down to the beach since mid-February. I did bring back a couple of pieces of fresh sea lettuce then, and I found a big leaf of fresh Turkish towel, which lasts well in the tank. But there was little eelgrass to go with it, and no replacements since then. The tank is bare; an underwater desert, decorated with small shreds of fading Turkish towel, stripped of any food value.

One of the smaller hermits, on a barnacle-covered stick.

I read somewhere that hermits will eat ordinary people-food lettuce. Worth a try; I tore off a bite-sized piece and anchored it in the sand. Within a minute, the largest hermit and the crab were having a tug-of-war over it, yanking and pulling and at the same time tearing off pieces and shoving them into their mouths. (It's handy having so many grabbing mouth parts.)

I added a few more pieces of lettuce for the rest of the crew. That was a couple of hours ago. They have eaten it all, leaving only a few floating shreds, as thin as soggy tissue paper.

Hermit on lettuce leaf, all stretched out to grab as much as possible before the rest get there.

Hermit on the far side of a scrap of lettuce. His shell is showing through the hole someone has already torn.

As far as I can tell, all the hermits got a chance at the lettuce. The largest one stuffed himself so much, finishing off one piece and going to the next, and the next, that I wonder how he fits into his shell now.

I saved a leaf for them tomorrow; I ate the rest.

Hurry, hurry! Dinner is served!

I wonder if they like cilantro? I've got a big, fresh bunch.

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3 comments:

Beth Niquette said...

How fun! I loved this set of photos--especially the one with the heart!

Happy Guest Heart Thursday!

Laura said...

what a wonderful observation, finding this little heart.

Clytie said...

I love when you post about your tank critters. The heart is awesome!!!