Branching or Colonial hydroids?

PR_nano · Jul 3, 2020

Trying to confirm if these are colonial hydroid (Obelia longissima or Obelia dichotoma) or something else also is it safe to pluck away? That's what I been doing but have heard mix reviewed due to they being asexual. Lastly anyone knows a natural predator? I read some types of hydroid sting to protect from predators but haven't found out what is this predator that gets mentioned.

tsouth · Jul 3, 2020

These are branching. With them being on the plug - I would advise removing the frag outside of the water,l and scrubbing or peroxiding them away if you can, and then rinsing them in sw before placing them back.

There are sea hares that will eat hydroids, but I do not have first hand experience with them - and have only found that they're hard to find in the aquarium trade - Dolabella auricularia aka Wedge/Blunt edge sea hare.

Lastly, if worst comes to worse, fenbendazole has been tested to remove hydroids.

I've found that reducing broadcast feeding and removing foods like reefroids or benepets or phyto from your menu will help starve them out.

Good luck

PR_nano · Jul 4, 2020

@tsouth thanks, I really appreciate the info. I will keep plucking away and look into peroxide dipping. LiveAquaria currently have the sea hare in stock but it sounds to risky. For food I combine oyster feast and amino/omega with the mysis and/or reef riot fish food.

Pkunk35 · Apr 6, 2021

OP how was your battle with these hydroids? I have been scrubbing away at these for a couple weeks and have them under control but can’t eradicate them totally. Did you attempt to starve them out at all? I have been doing only manual removal and siphon but just can’t get the last 5% out. Thinking about removing all plankton foods for a week and continuing manual removal seeing if that does the trick.

Also, is it verified that peroxide dips work on these critters? It would be helpful on the zoas which seem to attract these things more readily for me than other coral.

Brad Vaughn · Dec 20, 2023

Pkunk35 said:
OP how was your battle with these hydroids? I have been scrubbing away at these for a couple weeks and have them under control but can’t eradicate them totally. Did you attempt to starve them out at all? I have been doing only manual removal and siphon but just can’t get the last 5% out. Thinking about removing all plankton foods for a week and continuing manual removal seeing if that does the trick.

Also, is it verified that peroxide dips work on these critters? It would be helpful on the zoas which seem to attract these things more readily for me than other coral.

Hey did you get rid of yours? I have them ... again. =(