Kurt_Nelson
Aquarium Advice Addict
OK... I've been trying to get a good picture of these things for months, and last night an asterina star and one of them made for a great photo opportunity.
Here's the picture, and then a description...
The white worm-like things live in one place in the sand. They don't seem to move around. They poke their "heads" out of the sand normally at night - or during the day if there's food in the tank, or an unlucky snail/star wanders too close - and lay their tentacles flat against the sand... kind of like a trap. The upper part of them are white and the lower part are kind of brownish. Of the few I've managed to grab with tweezers and yank out, the largest ones are only about 1/2" to 3/4" long. Hard to tell since they're just kind of a shriveled mass when they're out of the water.
The tentacles will retract into the "tube" when it's disturbed, and the whole tube will retract down in to the sand. Very very hard to grab the things. Only way I've gotten them before is when they're eating something hard and I can grab the whole thing, pinching the hard thing they're eating. Even though the things are at MOST 1/8" in diameter, then can "swallow" a small nassarius whole. I've witnessed it. I think that's why over the last 6 months or so I've had a hard time keeping them alive in my tank. When I add them, on average I lose two within the first hour after they crawl across one of these little land mines.
Sooo... after doing a bunch of research, I *think* I may be dealing with some type of hydroid, and not a worm. But the problem is I can't really find any pictures of hydroids that look like these. Tons of different hydroids, and tons of pictures... but I just keep coming up with nothing.
Now that I've gotten a good picture, hopefully someone here will be able to steer me in the right direction. Oh... and after I finally got the picture, I rescued the asterina star. It's doing fine now.
Here's the picture, and then a description...
The white worm-like things live in one place in the sand. They don't seem to move around. They poke their "heads" out of the sand normally at night - or during the day if there's food in the tank, or an unlucky snail/star wanders too close - and lay their tentacles flat against the sand... kind of like a trap. The upper part of them are white and the lower part are kind of brownish. Of the few I've managed to grab with tweezers and yank out, the largest ones are only about 1/2" to 3/4" long. Hard to tell since they're just kind of a shriveled mass when they're out of the water.
The tentacles will retract into the "tube" when it's disturbed, and the whole tube will retract down in to the sand. Very very hard to grab the things. Only way I've gotten them before is when they're eating something hard and I can grab the whole thing, pinching the hard thing they're eating. Even though the things are at MOST 1/8" in diameter, then can "swallow" a small nassarius whole. I've witnessed it. I think that's why over the last 6 months or so I've had a hard time keeping them alive in my tank. When I add them, on average I lose two within the first hour after they crawl across one of these little land mines.
Sooo... after doing a bunch of research, I *think* I may be dealing with some type of hydroid, and not a worm. But the problem is I can't really find any pictures of hydroids that look like these. Tons of different hydroids, and tons of pictures... but I just keep coming up with nothing.
Now that I've gotten a good picture, hopefully someone here will be able to steer me in the right direction. Oh... and after I finally got the picture, I rescued the asterina star. It's doing fine now.
