They do have only one appendage. I suppose the jellyfish looking part may be some tentacles, but it's really hard to tell because they're so small.
Edit: They don't look anything like the pictures of planaria I saw in a google search. They do look much smaller than the hydra I saw in pictures, and they seem to look different although it's hard to see them. Maybe they'll get bigger, and I'll be able to give a better description.
Yes, I did figure that the pleco may get too large for the tank eventually (the sign at the store said up to 24 inches, I think.) I'm hoping he'll stay reasonably small, but if he starts getting too big I won't hesitate to put him up for adoption. He may even get moved to a larger tank eventually, if I can afford to buy one by then.
He's technically my roommate's fish, since he was envious of all of my fish. Very shy, but warming up a bit; we see him waking up in the evening lately, before turning out the lights.
Edit: As a side note, I think a few of my neon tetras might be pregnant. Possibly from the change between the petstore water and my tank water? I did do an extra water change after moving them in, since I wanted Ray to keep some of the water he was used to. I don't expect any fry to make it, but it will be interesting to see if it happens.
Last edited by GamerGuy; 01-02-2012 at 04:54 AM.