ID on brown slug with a red dot??

[DanH]

I seem to have a herd of these tiny brown slug like creatures on my glass. Any ideas? They only seem to be interested in algae (at the moment). I'm keeping a close eye on my corals just in case. Could they be baby versions of two larger slugs I have in my tank? Sorry no pic at the moment. I saw these two spitting out hundreds of tiny eggs about a week ago (Much to the delight of my fish - I would be suprised if any of these eggs made it.

 

[brandonberry]

It is commonly called a red planaria. It is a kind of flatworm. They can multiply quickly to plague proportions. They can be controlled with Flatworm Exit, made by Salifert, however they can release toxins which kill fish. Mandarins and six-line wrasses have been known to eat them, but if you have a large proportion of them, it is unlikely you will control them with with this method. I've heard some people say that they have used flatworm exit at night with no harm at all to their fish. Supposedly there is some evidence to suggest that the fish dieing has to do with the fish actually eating the flatworms when they fall off and float into the water column. By treating the tank while the fish are asleep you avoid this. When I have used it, I cleaned my skimmer first and made sure it was running at maximum efficiency before dosing the tank.