I'd Really Love To Know What This Is

I'm amazed that my camera could catch such detail of these guys.


They are the most recent additions to my glass, and sand, and to a lesser extent, LR. I don't know what way is up or down with these guys, and for all I know, they might not either.




They don't seem to be a nuisance or threat to any of my corals or fish. I have two banggai cardinals, a zoa-covered rock, a very healthy green star polyp, a beautiful mushroom-covered rock (which has gone from 15 to 20 polyps), and a yellow polyp that's doing great.



These honestly look just like cannoli shells but they're green. They have a rich red nodule towards the "top" center. They also have what appears to be a feeder/siphon that slowly whips back and forth at the head.

I should mention they're soft and fleshy and have pretty good ability to move on the glass. They can turn in a complete circle inside of a second when they want. At first there were a few, then lots, dozens, now hundreds. The population growth is maybe two months in time.
As far as size goes, they're almost as large as the date on a dime.



Anyone ever see these?

 

looks like some kind of baby snail or nudi maybe but hard to tell

 

+2 sure is hard to say I hope they are freindly thou.

 

Its flat worm!! Start perpearing to remove them from your tank - or get a 6 line wrasse.
My lfs also uses dragonets to remove them.

 

+1 on flatworms, yellowtail damsels work great on destroying them. if you have a lot of them, flatworm exit should be your next purchase.

 

That's why I love this site! It seems they are flatworms. I searched and found an earlier thread where amcarrig correctly identifies these as red planaria. I found some info on melev's site, and read about flatworm exit.

Being somewhat adverse to chemicals in my tank, I'm going to try to siphon out as many as I can first, and maybe employ a sixline wrasse or dragonet.

 

Im with you, I almost bought the flatworm exit, but after reading the instructions, OMG, you HAVE to make sure that you siphon EVERY single dead FW or they release toxins in your tank. SIPHON? Good luck with that, Thats highly impossible to get every single one out. My sixline doesnt do a damn thing b/c he gets all the food that he needs from the other fish foods. Luna

 

Wish you luck in your endeavors to get rid of them. I too have fought with AEFW and Monti eating Nudi's so I know how you feel. Get a six line and he will help keep the population in check.

 

Thats actually a acoel worm, Convolutriloba retrogemma. They are harmless aslong as their numbers are kept in check, but can easily get out of hand and smother corals and other sessile inverts.

 

Thanks Luna. As far as siphoning them, I'm going less for anihilation and more for simply thinning their numbers. Less parents, less kids. I'm reading that they dislike water flow, so I'm sticking a koralia 2 on the side opposite my vortech.

I've read too that their populations can be fleeting--many today, none in a month.

I'd love some more opinions from my friends here!