Tunicates Blooming in Display Tank - Need Advice!

[Aiden22!]

Hey Reef2Reef fam,

I acquired a rock from an old head reef hobbyist about 7 months ago. This enthusiast used to collect rocks in Fiji and had some extra in his blacked out sump. To quickly cycle my new upgraded display I added the Fiji live rock to my sump. Recently, I've noticed a bloom in my tank, with tunicates appearing in small colonies in the sump. About a month ago, they started making their way into the display. Some have even began growing on the skeleton of my acanthophyllia!

I'm curious if it's okay for tunicates to grow in the display, and if the ones in the picture will be fine. Additionally, any insights on keeping them happy in the tank? Your expertise is much appreciated! #reeftank #Tunicates #AquariumAdvice

 

[EeyoreIsMySpiritAnimal]

I have no advice, but that's so cool!!

 

[Aiden22!]

I have no advice, but that's so cool!!

haha thanks! Reefing can be so rewarding sometimes.

 

[Reefing102]

My experience with tunicates is they come and go as food supplies vary. When I was feeding live phyto they lasted alot longer than they currently.

 

[Aiden22!]

My experience with tunicates is they come and go as food supplies vary. When I was feeding live phyto they lasted alot longer than they currently.

Great I’ll keep that in mind! Much appreciated!

 

[ISpeakForTheSeas]

I'm curious if it's okay for tunicates to grow in the display, and if the ones in the picture will be fine.

Yeah, tunicates (and sponges too, which at least some and probably all of the “colonies” in your pics are sponges) are generally perfectly fine to grow in your DT.

For tunicates, only highly invasive species (like Botryllus and Botrylloides species, which you definitely don’t have) should cause any issues at all, and that’s because they start growing over just about everything (including coral flesh/polyps [not just skeleton, which can be grown over without causing harm], macroalgae, etc.). They should be easy enough to scrape off as long as they’re relatively contained though.

For sponges, most sponges are completely harmless, but a few are invasive and/or harmful; the harmful ones can chemically harm nearby corals (causing them to be visibly unhappy) and/or grow over the flesh of the corals and smother them. That said, most invasive sponges are still harmless and won’t grow over/smother corals (though several will grow up and around the base/stalks and skeletons of corals - it’s generally only harmful if the sponge covers the polyp/flesh), but they’ll take up a lot of “real estate” in the tank. As I currently understand it, invasive sponges can be more difficult to get rid of then invasive tunicates, but most still aren’t too bad, and can be scraped off to make room for new frags as needed.

To clarify here - from what I can tell, the pink thing in the first pic a sponge, likely a Dysidea sp. such as D. avara. Dysidea species have a rather unique texture to their surface, so I’m fairly confident on this one, but a few other sponges have similar textures as well. The gray ones in the second pic are the ones that I’m the least sure on, but I’m still inclined to guess it’s a sponge - colonial tunicates are typically very uniform, with all of the in-current siphons being roughly the same size and shape and being distributed very uniformly as well; sponges tend to be less uniform and more haphazard with their in-current siphons; I can’t see the specimens clearly enough to say for sure, but they look a bit haphazard with shape and placement in some places. The pink and yellow ones in the third pic have growth patterns (like the spiky growths visible on the pink one at the top) that I’ve never seen on tunicates before, so I’m fairly confident they’re sponges too. I see a bunch of little gray blobs in the pic that I’m assuming are either sponges or tunicates as well, but I can’t see enough detail on them to say for certain.

Regardless, sponges or tunicates or both, I agree that it’s cool to see them doing well in your system!

Additionally, any insights on keeping them happy in the tank?

From what I recall at the moment of what I’ve been able to gather, tunicates really just need a proper flow and some phyto to do well; sponges are (somewhat ironically) a bit more complex with their diet, so maintaining good health in sponges can be difficult depending on the sponge and the tank. Since the specimens in your tank seem to be doing well and spreading, I’d assume your tank has the proper conditions for them to thrive (so keep doing what you’re doing, and they’ll probably be happy).

I am curious, are you doing anything special to keep these doing well? Dosing phyto or anything?

 

[Aiden22!]

Yeah, tunicates (and sponges too, which at least some and probably all of the “colonies” in your pics are sponges) are generally perfectly fine to grow in your DT.

For tunicates, only highly invasive species (like Botryllus and Botrylloides species, which you definitely don’t have) should cause any issues at all, and that’s because they start growing over just about everything (including coral flesh/polyps [not just skeleton, which can be grown over without causing harm], macroalgae, etc.). They should be easy enough to scrape off as long as they’re relatively contained though.

For sponges, most sponges are completely harmless, but a few are invasive and/or harmful; the harmful ones can chemically harm nearby corals (causing them to be visibly unhappy) and/or grow over the flesh of the corals and smother them. That said, most invasive sponges are still harmless and won’t grow over/smother corals (though several will grow up and around the base/stalks and skeletons of corals - it’s generally only harmful if the sponge covers the polyp/flesh), but they’ll take up a lot of “real estate” in the tank. As I currently understand it, invasive sponges can be more difficult to get rid of then invasive tunicates, but most still aren’t too bad, and can be scraped off to make room for new frags as needed.

To clarify here - from what I can tell, the pink thing in the first pic a sponge, likely a Dysidea sp. such as D. avara. Dysidea species have a rather unique texture to their surface, so I’m fairly confident on this one, but a few other sponges have similar textures as well. The gray ones in the second pic are the ones that I’m the least sure on, but I’m still inclined to guess it’s a sponge - colonial tunicates are typically very uniform, with all of the in-current siphons being roughly the same size and shape and being distributed very uniformly as well; sponges tend to be less uniform and more haphazard with their in-current siphons; I can’t see the specimens clearly enough to say for sure, but they look a bit haphazard with shape and placement in some places. The pink and yellow ones in the third pic have growth patterns (like the spiky growths visible on the pink one at the top) that I’ve never seen on tunicates before, so I’m fairly confident they’re sponges too. I see a bunch of little gray blobs in the pic that I’m assuming are either sponges or tunicates as well, but I can’t see enough detail on them to say for certain.

Regardless, sponges or tunicates or both, I agree that it’s cool to see them doing well in your system!

From what I recall at the moment of what I’ve been able to gather, tunicates really just need a proper flow and some phyto to do well; sponges are (somewhat ironically) a bit more complex with their diet, so maintaining good health in sponges can be difficult depending on the sponge and the tank. Since the specimens in your tank seem to be doing well and spreading, I’d assume your tank has the proper conditions for them to thrive (so keep doing what you’re doing, and they’ll probably be happy).

I am curious, are you doing anything special to keep these doing well? Dosing phyto or anything?

Impressive response! I'm aligned with the sponge theory and lean towards them not being tunicates upon further investigation. I've made a shift from spot feeding reef roids to regular dosing of ab+ and elevating nutrient levels with less frequent water changes—raising Nitrate from 10-20 ppm to 30-50 ppm and Phosphate from 0.15 to approximately 0.25. Honestly, this nutrient increase was driven by my frequent travels, leaving me with less time for maintenance. Notably, the sponges in my sump have flourished since I blacked out the sump after removing the macro algae section. Perhaps the reduced algae presence has contributed to their growth. Thanks for the reply your insight has been helpful and appreciated!

 

[ISpeakForTheSeas]

I've made a shift from spot feeding reef roids to regular dosing of ab+ and elevating nutrient levels with less frequent water changes—raising Nitrate from 10-20 ppm to 30-50 ppm and Phosphate from 0.15 to approximately 0.25.

Ah, yeah, that makes sense that they’d be doing well then - reef roids are too large to be sponge food, but ab+ has some phyto and (according to their site, though they don’t list micron sizes) DOM, so there’d be some good food there for them. That in combination with the high nutrients and infrequent water changes probably providing a good environment for bacterial growth would be a good a setup for a lot of sponges.