🧽 sponge

[Minireeftank]

I have a sponge that seems to have taken over my zoanthid, the colony started off very well and all the other corals are very happy, however the colony had now completely disappeared, strangely another colony of zoas on a different rock has also been disappearing despite their being no sponge on it, my only theory is that my hermits ate the dead zoas taken over by the sponge and got a taist for them and ate the others too- not sure if that’s even possible, a few months ago I got some nudibranches to try and keep the aiptasia from taking over but I thought they’d all died as after a couple of weeks the aiptasia came back and I stopped seeing them I know some types of nudis eat zoas but I’m sure they were eating the aiptasia in the beginning- I’d like to add more zoas, the rock that was taken over by the sponge is home to a pompom crab so I can’t get rid of it although it doesn’t look great now but I don’t want the sponge to take over them too - any ideas? I’ve lifted it out the water enough for the sponge to get air in it as I saw this suggested but it didn’t work and I don’t want to take the rock fully out as the little pompom crabs in it

I don’t have any good pictures of what the old colony looked like but you can see it in the background here and there were lots of polyps 

[seabass]

Berghia nudibranchs shouldn't be harming zoanthids.  I'm guessing that something besides the sponge is causing the decline (like zoanthid eating nudibranchs, sea spiders, sundial snails, Zoa Pox, etc).

 

Out of curiosity, what are your tank's phosphate and nitrate levels?

[BioBoy16]

How quickly are they disappearing? Did u wake up one morning and poof alot were gone or does a couple go missing each day? I've never had my hermits pick at any of my corals. They got so hungry one time I watched them chase my mandarin around the tank still didn't touch a coral or zoa. I'd look up zoas "melting" too. I've heard that thrown around but I'm not entirely familiar with the term.

[Minireeftank]

9 hours ago, seabass said:

Berghia nudibranchs shouldn't be harming zoanthids.  I'm guessing that something besides the sponge is causing the decline (like zoanthid eating nudibranchs, sea spiders, sundial snails, Zoa Pox, etc).

 

Out of curiosity, what are your tank's phosphate and nitrate levels?

I only have test strips at the moment so they give a vague reading but their on the lowest end 

7 hours ago, BioBoy16 said:

How quickly are they disappearing? Did u wake up one morning and poof alot were gone or does a couple go missing each day? I've never had my hermits pick at any of my corals. They got so hungry one time I watched them chase my mandarin around the tank still didn't touch a coral or zoa. I'd look up zoas "melting" too. I've heard that thrown around but I'm not entirely familiar with the term.

It has been a gradual decline but it started when the sponge appeared 

[seabass]

I asked, because low nutrients can be a problem for zoanthids.  However, it could be any number of things (or combinations of things).  As you implied, certain sponges can irritate zoanthids; although I'm not sure that this is what's happening here.

[Minireeftank]

10 hours ago, seabass said:

I asked, because low nutrients can be a problem for zoanthids.  However, it could be any number of things (or combinations of things).  As you implied, certain sponges can irritate zoanthids; although I'm not sure that this is what's happening here.

I have got a large number of bristleworms that May have bothered them- do you have any experience with bristleworm predators- I have looked into arrow crabs and coral banded shrimp but it seems they kill hermit crabs and snails, I have a 52L tank ?

[seabass]

Common bristle worms shouldn't cause problems for healthy corals.  They (and other scavengers) often get blamed for losses when they are most likely just cleaning up dying tissue.  Although I'm not sure about other fire worms, which seem to have a worse reputation.

[BioBoy16]

Huh interesting they're gradually disappearing. from the pics it kind of just looks like many are unhappy. They shrink up pretty good when they close up. You may have not lost as many as you think. Give it time they're pretty resilient and might bounce back.