Sea Urchin Wipe Out

[WJ18]

I recently have had 6-7 sea urchins in my 120, all doing fine, active etc. 10 days ago, I impulse bought a short spined urchin from Petco. 3 days later he started losing spines and died the next day. Since then, all my urchins (except for 1 tuxedo) have done weird stuff like hanging off the glass sideways and partially upside down. (See pics) and have been dying. My tank parameters are stable,(temp, alk, ph) 78.5-79, 7-9 dkh, 1.025sal. I have a hydros and checked temp/ph for spikes. What do you guys think?

 

[WalkerLovesTheOcean]

Urchins are extremely sensitive inverts. I would say that the PetCo urchin was just a dud, and wasn't healthy from the get-go, or died due to improper acclimation. 6-7 urchins is way too many urchins for that sized tank, they are all probably starving. Do you see any algae in the tank, or have you been supplementing their diets at all?

 

[WJ18]

Urchins are extremely sensitive inverts. I would say that the PetCo urchin was just a dud, and wasn't healthy from the get-go, or died due to improper acclimation. 6-7 urchins is way too many urchins for that sized tank, they are all probably starving. Do you see any algae in the tank, or have you been supplementing their diets at all?

They all starved at the same time though?
Within 10 days of each other. Not trying to argue though, it’s possible.

 

[WalkerLovesTheOcean]

They all starved at the same time though?
Within 10 days of each other. Not trying to argue though, it’s possible.

Well, yeah... if you had an algae source, and then they ate it all, they would all starve at a relatively similar rate. Still, I'm not saying that starvation is the cause. There could have been some contaminant in your water, or even some disease. Starvation is just one of the possible causes.

 

[PR_nano]

Icp? Maybe some minor elements are off/depleted or pollutants. How about other inverts are they doing fine? Corals look good from the pictures.

 

[WJ18]

Icp? Maybe some minor elements are off/depleted or pollutants. How about other inverts are they doing fine? Corals look good from the pictures.

Other inverts are fine, couple fighting conchs, coral banded shrimp, snails.

 

[Gumbies R Us]

icp might be a good option, wondering if their is something in the water that could be bothering them.

 

[Dragen Fiend]

I've always used urchins as a reference to poor tank quality. They are always the first ones to show signs of problems and die.

I'm not to familiar with any sort of disease that could affect urchins only. Possibly you could have brought something in from that sick urchin. Or the other urchins were already showing signs from poor chemistry in the tank and you might have not noticed until the new one started to die.

6+ urchins is a lot for even a 120g tank. These can mow through algae. I had to supplement algae for a single one in a 20 gallon tank.

If you can visibly see algae available. Then maybe not starving but I suspect they are. Recheck all your parameters. I would be running activated carbon as well.

 

[kevgib67]

They all starved at the same time though?
Within 10 days of each other. Not trying to argue though, it’s possible.

First your tank is beautiful, well done! Walker makes a valid point, your tank looks very clean and I can’t see any algae, at least from the picture. You would need a lot for that many urchins. This is one of those cases where they did to good of a job. I would hang on to the tuxedo and supplement with nori or algae pellets as needed. Sorry for your loss, it’s always tough loosing animals that you care about.

 

[Tahoe61]

Did you get all the Urchins from Petco? If so I would suggest they were already compromised prior to your purchase.
My local Petco had a large shipment of Urchins recently. The holding tanks provided no supplemental algae to feed on.
I have fish, corals and inverts that I purchased from Petco, all are alive and well. With that said the water chemistry and husbandry at Petco is dismal at best.
I purchased the last remaining Urchin, all others had died. I feed the Urchin sheets of Nori.