What the heck is this little creature?

[Sailor]

A few days ago I started noticing these little buggers clinging to the back wall of my tank. In just a short while there’s now about 30 or 40 of these guys, and most of them are gathered on one side of the overflow box, and there are a few in the sump.

Prior to posting my query I thought I had better do my own research, and sure enough, I found a similar photo and short description right here in the R2R sticky threads on the Hitchhiker forum. Evidently, this is a Pineapple Sponge, and it’s said to be a “very common good hitchhiker.” Really?

Right now most of these are no bigger than a grain of rice. But I understand they can grow much larger. And although they’re not supposed to be harmful, they’re not an attractive addition to the tank. I want them gone! I’m sure I can scrape them off the glass and scoop or suck them up one way or another, but why are they here in the first place? And how do I keep them from coming back?

One source tells me a nutrient issue could cause a pineapple sponge population explosion. I am battling a nutrient issue right now after recent efforts to mitigate a Cyano and Dino outbreak. My nitrates and phosphates have been zero for at least a week, maybe longer. Well, I finally got the PO4 off rock bottom a day ago. They’re at 0.02 today, but nitrates are still undetectable. I’ve been told I’m over-filtering, running the skimmer 24/7. I thought that was normal. Or maybe I’m not feeding enough. There are only 8 small fish in the 112g tank now, so that’s a very light bio load.

If this was your tank, what would you do about these critters?

 

[EricR]

Pineapple sponge. I think the consensus is they'll likely go away on their own once silicates dissipate but don't quote me on that.

I had to pull one cause it was in the middle of some zoas that had grown into a shady area and it was irritating them. If not bothering anything though, I think they look kinda cool.

 

[ying yang]

If my tank ,I would do nothing which is exactly what I do in my tank,I mainly only see them in sump where its darker,and occasionally inbetween rock crevices or under corals in dt but don't see many in dt at all tbh.
Maybe something eating them or displacing them in dt idk.
But just adds to the variety off life in my tank which I want unless detrimental to Any livestock which they aren't

 

[jabberwock]

I would individually hug each one of them. I like them.

 

[A Young Reefer]

Pineapple sponge. I think the consensus is they'll likely go away on their own once silicates dissipate but don't quote me on that.

I had to pull one cause it was in the middle of some zoas that had grown into a shady area and it was irritating them. If not bothering anything though, I think they look kinda cool.

^

 

[Biglew11]

I'd leave them, I had a small hand full and now can't find any.

 

[Sailor]

Thanks everyone for confirming the ID and sharing your thoughts on Pineapple Sponges. It’s reassuring to know they are harmless. And I can appreciate the concept of welcoming new, exotic aquatic life into one’s slice of the ocean in their home, but I’m somewhat surprised by how much you guys seem like, or at least accept these critters, as if they were fuzzy, cuddly little pets. But right here, right now in my tank they look like a splattering of maggots stuck on the wall — not very attractive! And I apologize for projecting that visual. But they stand out like a sore thumb — white blobs on a black background. Not good.

So, I’m hoping nature will take its course and they’ll eventually just disappear. Meanwhile, I’m going to try to expedite the process by figuring out why they’re here and then make the necessary environmental adjustments to eliminate them. Coincidently, I’m shipping a water sample to an ICP lab this week. That’ll help troubleshoot both Dino and sponge issues.

 

[Mikedawg]

Thanks everyone for confirming the ID and sharing your thoughts on Pineapple Sponges. It’s reassuring to know they are harmless. And I can appreciate the concept of welcoming new, exotic aquatic life into one’s slice of the ocean in their home, but I’m somewhat surprised by how much you guys seem like, or at least accept these critters, as if they were fuzzy, cuddly little pets. But right here, right now in my tank they look like a splattering of maggots stuck on the wall — not very attractive! And I apologize for projecting that visual. But they stand out like a sore thumb — white blobs on a black background. Not good.

So, I’m hoping nature will take its course and they’ll eventually just disappear. Meanwhile, I’m going to try to expedite the process by figuring out why they’re here and then make the necessary environmental adjustments to eliminate them. Coincidently, I’m shipping a water sample to an ICP lab this week. That’ll help troubleshoot both Dino and sponge issues.

Beauty is in the eye of the beholder, lol

 

[Biglew11]

Bottom line is they are there because you have enough dissolved organics in the tank to support them.

The only way way to expedite the process naturally is to stop feeding anything in the tank. Pretty drastic for a process that will happen on its own.

Now if you don't like the look of them where they are just scrape them off.

 

[Sailor]

Bottom line is they are there because you have enough dissolved organics in the tank to support them.

BigLew says I have enough dissolved organics in my tank to support the sponges. That’s a logical assumption, inline with conventional wisdom. But my Hanna Checkers show that I’ve had zero nitrates and zero phosphates for weeks now. Just the other day my PO4 came up off zero to 0.02. That’s why I’ve been battling Dinos, which we’re learning now that they thrive in low-nutrient environments.

So I’m between a rock and a hard place. On the one hand, I have sponges multiplying in my tank… because they can! Evidently, there’s enough nutrients to support them. And the appropriate action would be to cut back on feeding. On the other hand, I have dinoflagellates because they thrive in a low-nutrient environment, and my research (both here on R2R and elsewhere) tells me I’m over-filtering and should cut back on skimmer use and feed more (not less).

It’s a conundrum! The cure for one problem exacerbates the other.

Anti-Dino measures also include dosing beneficial bacteria, lowering the photoperiod and intensity of the lights, raising the temp a little and adding a UV sterilizer. I’ve already done all that. Some say I should proactively dose both NO3 and PO4. I have not done that. Not yet, anyway.

And I have not changed my feeding habits. I feed twice a day only what the fish eagerly chase after in about a two minute period. And although the skimmer runs 24/7, it makes frothy foam only when the water parameters and surface tension support it. I don’t actually track it but I see it making (usually wet) skimmate several hours at a time and not making foam at other times. And it’s random. I can’t spot a pattern.

 

[Biglew11]

nitrates and phosphates aren't the only organics in a tank just the two that are easily measured. these sponges are filter feeders meaning they feed on very small particles of organic carbon compounds, food, bacteria, etc. these sponges really aren't a problem. they may be ugly to you, but they are in no way a problem that needs to be addressed. if you don't like where they are just scrape them off.

 

[Erikhsf]

BigLew says I have enough dissolved organics in my tank to support the sponges. That’s a logical assumption, inline with conventional wisdom. But my Hanna Checkers show that I’ve had zero nitrates and zero phosphates for weeks now. Just the other day my PO4 came up off zero to 0.02. That’s why I’ve been battling Dinos, which we’re learning now that they thrive in low-nutrient environments.

So I’m between a rock and a hard place. On the one hand, I have sponges multiplying in my tank… because they can! Evidently, there’s enough nutrients to support them. And the appropriate action would be to cut back on feeding. On the other hand, I have dinoflagellates because they thrive in a low-nutrient environment, and my research (both here on R2R and elsewhere) tells me I’m over-filtering and should cut back on skimmer use and feed more (not less).

It’s a conundrum! The cure for one problem exacerbates the other.

Anti-Dino measures also include dosing beneficial bacteria, lowering the photoperiod and intensity of the lights, raising the temp a little and adding a UV sterilizer. I’ve already done all that. Some say I should proactively dose both NO3 and PO4. I have not done that. Not yet, anyway.

And I have not changed my feeding habits. I feed twice a day only what the fish eagerly chase after in about a two minute period. And although the skimmer runs 24/7, it makes frothy foam only when the water parameters and surface tension support it. I don’t actually track it but I see it making (usually wet) skimmate several hours at a time and not making foam at other times. And it’s random. I can’t spot a pattern.

How old is your tank? I had the same sponge’s in my tank around the same time as Dino’s I can’t remember which one came first or left first. But I didn’t lose any corals from either of them and are both gone now I believe it is just part of the bio diversity working it self out. My tank was only like 6 to 8 months when it happened the majority where in my sump too but there where plenty in my display. I believe they eat silicates but either way you can show 0 on your p04 and n03 but have higher levels it’s just everything in the tank is consuming it. But how about this why did you get a reef tank to enjoy the Reef right well this is part of the reef they are there doing a job just like everything else everyone calls pests. If you remove them your Dino’s could get way worse or throw something else out of wack there there for a reason and will disappear when there done. Enjoy your tank and all the amazing things the just appear out of know where. These things all help your tank in more ways then we know if you want a balance biomass in your tank then stop fighting all the little things.