Worm food

It was feeding time in the aquarium again. I dropped in the usual Crab Cuisine pellets, about one per hermit crab. (One is too much for a tiny hermit, but the big guys collect two or three each.) As always, there was great excitement, as crabs and hermits and the one remaining shrimp raced around, trying to get to the table first. But when they'd all retired with their goodies to their preferred eating spots, one pellet had been missed, right up against the glass. And then the 15-scale scaleworm slid timidly out of hiding, tracking down that delicious scent of fish and corn.

Scale worm. Belly view; the edge  of some scales on his back are just barely visible.

Licking his lips already

"Look what I found! Oh, this looks good!"

These worms eat by everting their jaw some distance beyond the face, and biting down. I've watched them many times, but never actually seen the everted jaw. It all happens in a split second; the worm is there, looking at the food from a short distance away, then there's a moment of blur, and then all is as before, except that the food has moved.

This time, with the worm and his lunch so close to the glass, I set the camera down, focussed on the pellet, and tried to catch the action. The worm was biting at the edges of the pellet; it was too big for him to swallow. After each bite, he'd back off, rest a minute, and then, - snap! - take another bite.

Mostly, by the time my finger pressed the camera shutter, it was all over. I tried anticipating his moves, and finally got one blurry view of that speeding jaw.

Snap!

A few more bites, and the worm retreated into his seaweed hidey hole, leaving the rest of the pellet for midnight snackers.

Disappearing plates

I've been finding quite a few scale worms recently, in the eelgrass beds, and in my tank. I got one to sort of settle down in a tray for a minute.

Fifteen-scaled worm, Harmothoe imbricata

I've counted and counted: I can only find fourteen scales on either side, but the tail end has been damaged, so some may have fallen off.* The scales are like little round, overlapping plates that protect the whole worm, right up to the 4 eyes. They may help in swimming, which these critters do much more gracefully than other worms.

These are free-roaming worms, sometimes crawling, sometimes swimming. I find them on clamshells, on stones, on eelgrass, out hunting. They eat amphipods and anything else small enough to be subdued. The largest I have seen is about an inch long.

*There's a beautiful photo of one of these on Flickr. And this one has the same problem with disappearing plates: I count 15 on one side, 13 on the other.

Underwater textures

Cake decoration ripples:

Small trophon snail, on barnacles. About 1 cm. long.

Smooth and rounded:

Anemone and bubble. Also about 1 cm. tall.

Layered and prickly:

Scale worm on rock.