Hydroids to Flatworms Hi Guys, I have a cluster of little brown pom-pom like things in my reef. Using the google search on your site, I found out that they are "a fairly common nuisance hydroid, Myrionema". My question was answered. <Good> While I was on the Hydrozoans FAQ page I noticed a posting titled "Stranded Hydroid! Yikes! 4/7/05". Your staff answered the question and identified the animal as a hydroid. I had similar things in my tank growing on a finger leather coral. It turned out to be some kind of flatworm. It had the same tentacles in the posted picture. The worm would release the tentacle into the current and pull it back repeatedly. <Strange, interesting... have not heard of, seen this offered re flatworm behavior ever> The worms are very clear, so they almost disappear when they are spread out over the surface of the coral which makes it seem that the tentacle is coming from the coral itself. <Good plan, eh?> I used Salifert Flatworm Exit in a bag of tank water and dipped the coral in it. After approximately 45 minutes the flatworm came off by creating a current in the bag with my finger. It was a clear, slightly cloudy flatworm. Even sitting on the bottom of the bag, it released the tentacle and pulled it back. The tentacle was a long single strand which had smaller lines coming off one side. I actually got a few of them using the dip. Each worm only had one strand - so if you see more than one - chances are that there are several worms. Great Site. <Thank you for this input. Will try to find the bit you reference and couple it with yours here> Dave