What is it??

[sdascher]

Hello all,
I am still a novice....... less than one year of enjoying the reef tanks! - I recently noticed these slug/snail like creatures were on the glass in the mornings, after the lights are on for a few minutes they are in hiding. There seems to be around 30 of them so far that I can see. They are approx. 1/4" long, creamy white, they seem to have a fish like tail with a white spot in the center. Does anyone know what these critters are??? I do have a picture, but I'm having a hard time attaching it to this message, I have tried several times. If you'd like to see a pic, please email.
Thanks for any info......
sdascher

 

[jonthefb]

congrats my firend you have.......flatworms! these guys are still kind of a mystery in the hobby, there are a few that feed on soft corals, but at the same time, the majority of htem do no harm. however they do reproduce very rapidly in a captive env. and can quickly reach plague proportioins. the most common one is the red flatworm. if your cool with it keep it but just be aware that most produce a toxin that is harmful to fihs, and if you have a mass die off at any point, you could lose a large amount of your livestock. i personally try to remove them at first sign. you can do this either by siphoning them out into a bucket with vinyl tubing, or by trying a natural method of predation with an arrow crab, sixline wrasse, or mandarinfish, if your tank can support him. i personally have had good luck using all three of these biological controls, but it depends on the animal
good luck
jon

 

[nacl-h2o]

The flat worm pictured is a preditor of small crustaceans such as copepods and sometimes juvenal isopods or amphipods, it is harmless. They will not get out of hand or cause any problems. Their populations usually jump up in a new tank and then taper off to a low population in time without causing problems.

 

[sdascher]

Thanks Jon & Dan for your reply's. I do have a mandar1nfish in the tank, but not an arrowcrab. So.... I think I make try to remove some in the mornings and let the mandarin take care of the ones I miss!! I just wanted to make sure that I didn't have to go into the panic mode!!
Thanks Guys!!