ID help!

Vitor · Sep 17, 2024

Just noticed this little guy on the glass. Anyone can help? Friend or foe?

ISpeakForTheSeas · Sep 17, 2024

That's a nudibranch that eats cnidarians of some kind - any chance you've been having issues with a specific kind of coral lately? SPS and softies are the typical prey.

vetteguy53081 · Sep 17, 2024

Vitor said:
Just noticed this little guy on the glass. Anyone can help? Friend or foe?

Non berghia and I would eliminate. Most will feed on coral tissue and algaes.
There is a special tank for them below:

Vitor · Sep 17, 2024

ISpeakForTheSeas said:
That's a nudibranch that eats cnidarians of some kind - any chance you've been having issues with a specific kind of coral lately? SPS and softies are the typical prey.

Man I have wondered why so many Zoas heads are closed a lot of the time. Could that be it? Sinularia also shrinks but I think that is normal as it always comes back stronger and is growing.
Tank is relatively recent. Is this one of those things that if you have one you likely have many?
Thanks!

Vitor · Sep 17, 2024

vetteguy53081 said:
Non berghia and I would eliminate. Most will feed on coral tissue and algaes.
There is a special tank for them below:

Thanks. Bah this makes me sad. Am I likely to have more of them?

twentyleagues · Sep 17, 2024

Vitor said:
Man I have wondered why so many Zoas heads are closed a lot of the time. Could that be it? Sinularia also shrinks but I think that is normal as it always comes back stronger and is growing.
Tank is relatively recent. Is this one of those things that if you have one you likely have many?
Thanks!

If its the zoa eating type yes they breed pretty prolifically.

ISpeakForTheSeas · Sep 17, 2024

Vitor said:
Man I have wondered why so many Zoas heads are closed a lot of the time. Could that be it?

Vitor said:
Is this one of those things that if you have one you likely have many?

Yes, and yes - the typical recommendation is dip the corals to get the adults off, then search for egg spirals on the corals and scrape off any you find (be sure to use personal protective equipment like gloves, chem goggles, and a well-ventilated area when doing this with zoas/palys).

ISpeakForTheSeas said:
my best guess would be Aeolidiopsis/Baeolidia harrietae (there's some dispute around what genus the critter should fall into).

Either way, if my guess is correct, it's a known zoanthid eater, and it takes the zooxanthellae from its prey and stores it for use in its own body.

ISpeakForTheSeas said:
My guess would be Baeolidia palythoae or Baeolidia harrietae - they eat zoantharians like palys.

Vitor · Sep 17, 2024

Well, I just found 3 more adults. So yup, we have a situation here. Unfortunately I don't have access to dips that are useful with pests I'm afraid. Only for bacteria and fungus it seems, like Seachem Reef Dip.
Would a freshwater dip help?

Vitor · Sep 17, 2024

ISpeakForTheSeas said:
Yes, and yes - the typical recommendation is dip the corals to get the adults off, then search for egg spirals on the corals and scrape off any you find (be sure to use personal protective equipment like gloves, chem goggles, and a well-ventilated area when doing this with zoas/palys).

Went to dip and noticed these as well. Any ideia?

twentyleagues · Sep 17, 2024

Vitor said:
Went to dip and noticed these as well. Any ideia?

Typical amphipods. Good guys.

Vitor · Sep 17, 2024

twentyleagues said:
Typical amphipods. Good guys.

Not all is lost

ISpeakForTheSeas · Sep 17, 2024

Vitor said:
Would a freshwater dip help?

I'm not sure what the best dip would be in this case - I've heard of using hydrogen peroxide dips before, but I don't know how safe/effective it would be.

In theory, you could just use a turkey baster or similar and remove any adults you see, but you'd want to be careful looking for them, as they can blend in pretty well.

And, yeah, those looked like amphipods.