Two Tuxedo Urchins not doing well...

[niQo]

I have two Urchins since this last Fall and they have always done really well. Actually some of my favourite and most valuable critters in my tank. They have really kept my algae in check. One is a blue Tuxedo and the other one is similar in size but has white spines that stick in all kids of directions. I think it is a Pincushion Urchin.

The issue: About a week or so one of them was on his side. This had never happened before, so I flipped him over and didn't think much of it. Thursday after coming home from work, both of them were on their side/back. Now I know something is not right! One of them has also definitely shrunk and has not been using stuff to camouflage himself. After flipping them over I put them on a sheet of nori. The Pincushion seemed to stay and eat, but the Tuxedo moved on and started going on new frags. Since I think I have flipped both again. I highly doubt they are both starving at the same time, because they appear to still roam around the tank and eat, but they seem to not be healthy and weaker than usual.

Since November I had my tank fallow and did not do (m)any water changes (or much maintenance in general), but they continued to thrive. About a month ago I added chemiclean to get rid of cyano and started dosing some Seachem Flourish Nitrogen, because it tested at zero. I think this is when I started noticing the tuxedo shrinking and turf algae thriving more. It seemed the urchins were not able to keep up anymore as they used to. My rocks are no where near as clean as they used to be. It did also take me about two weeks to replace the carbon after the dose of chemiclean, so perhaps it stayed in the water column too long...

About a week and a half ago I did a 8 gallon water change (out of 55 gallon total).

Questions:
- Is chemiclean harmful to Urchins? Could this have caused the initial issue?
- Could the water change have caused the Urchins to do worse? I'm tempted to do another water change, but I'm worried it may cause more issues.

I've had much "bad luck" with this tank and if these two urchins die my tank will be overrun by algae...

Thanks for the help!

 

[mta_morrow]

I have always had urchins in my tanks and have had this happen as well. You have done all the right things as far as feeding.

I use chemiclean as well but have always had the carbon ready along with a 20% water change.

That may be the culprit, but hard to tell.

I know they don’t particularly like big swings in nutrients or alkalinity.

 

[hdsoftail1065]

My first pin cushion done the exact same thing, falling over, falling off the glass. It never dropped spines during this period until after it died and then dropped them. I never could figure out what and why. I hope yours pulls through whatever it may be that's causing them to act this way. Hopefully someone with more experience can shed some light and help you.

 

[niQo]

I have always had urchins in my tanks and have had this happen as well. You have done all the right things as far as feeding.

I use chemiclean as well but have always had the carbon ready along with a 20% water change.

That may be the culprit, but hard to tell.

I know they don’t particularly like big swings in nutrients or alkalinity.

Thanks for the reply. I realize things don't live forever, it is just strange they are both not doing well at the same time. I don't think there would have been a big swing in nutrients or alkalinity, but I can't rule it out as I don't test too often. I would guess it is a water chemistry/pollution issue, but it is near impossible to figure out what it would have been.

My first pin cushion done the exact same thing, falling over, falling off the glass. It never dropped spines during this period until after it died and then dropped them. I never could figure out what and why. I hope yours pulls through whatever it may be that's causing them to act this way. Hopefully someone with more experience can shed some light and help you.

Thanks! I'm hoping the same thing!

 

[Hermie]

I just went to the LFS today and was about to buy a tuxedo urchin but I am not so sure anymore... The ones they had were not really moving, although one was clung to the glass. I was worried they were starving, and asked how long they were in the store. The employee said 1 month. If it was fresher I would have probably gotten one... but 4 weeks without decent food is too long. 2 weeks would be the max IMO.

 

[niQo]

I just went to the LFS today and was about to buy a tuxedo urchin but I am not so sure anymore... The ones they had were not really moving, although one was clung to the glass. I was worried they were starving, and asked how long they were in the store. The employee said 1 month. If it was fresher I would have probably gotten one... but 4 weeks without decent food is too long. 2 weeks would be the max IMO.

And they didn’t feed them for four weeks?? It might be fine if you have enough algae in your tank, but it might not be worth the risk.

 

[Hermie]

And they didn’t feed them for four weeks?? It might be fine if you have enough algae in your tank, but it might not be worth the risk.

the employee said he put some nori in there, but he did not sound convincing, and there were "mobile" competitors in that little "tank" IIRC which would have likely eaten the nori before the urchin got to it. There was virtually zero algae on the glass IIRC. They also have some Spotted Puffers that I've watched slowly diminish through starvation to the point of severe discoloration. It's really sad but I think that store doesn't feed their fish (much if at all). I can tell the puffers were dying, from one week to the next.

 

[niQo]

Update: my two urchins are still alive. The smaller one still isn’t looking great and spends much time upside down. The other is doing better I think. Still no idea what the cause might be.

the employee said he put some nori in there, but he did not sound convincing, and there were "mobile" competitors in that little "tank" IIRC which would have likely eaten the nori before the urchin got to it. There was virtually zero algae on the glass IIRC. They also have some Spotted Puffers that I've watched slowly diminish through starvation to the point of severe discoloration. It's really sad but I think that store doesn't feed their fish (much if at all). I can tell the puffers were dying, from one week to the next.

That’s just really sad