Pincushion Urchin

lefty · Jan 16, 2015

Hello all,

I have been trying to research these guys. I had a pincushion urchin for about 2 months. I believe it has just died. It hasn't moved in a day. When I touch it the spines react, and it will move a little, but that is about it. I have tried putting some Nori under it to try and get it to eat, but nothing. My question is can a temp change of about 2 degrees be a cause of death. My tank usually sits at 78 degrees, I did a water change and forgot to check my temp on the new water before putting in the display tank. After the change the temp was at 76. I checked all other parameters of the new water (RO/DI) and of my tank and they all check out ok. I have a 65 gallon tank with some polyps, a hammer, and a few fish. My CUC has had no ill effects.
Nitrite - 0ppm, Nitrate - <5ppm, Ammonia - 0ppm, Phosphate (hanna) 0, TDS - 0. Calcium - 450, Alk - 10Dk. I did have .001 change in salinity after changing the water, in the display tank using my refractometer. I'm really not sure what the cause could have been. Any help would be greatly appreciated.

Thank you, Dan.

reeflover · Jan 16, 2015

To see if an urchin is dead I usually look for spines falling off. Not sure what you mean by retracting but if it's spines are falling off it is a pretty good indicator that something isn't right.

Was the temperature change very quick? I know when I put new water in my tank for a water change I run a powerhead so that the water disperses immediate in case one of the parameters were off (temp, salinity) no one specific organism gets blasted with it

vic67 · Jan 16, 2015

If the water change wasn't huge (like 50%) I don't think the temperature difference would have been too stressful. If the spines are retracting/moving I think it's still alive. As mentioned the sure sign that it's dead would be the loss of spines.

lefty · Jan 16, 2015

It hasn't lost any spines at this point, but it doesn't move until I touch it. The water change was about 15% and the temp did drop fairly fast. I leave my power heads on as well when I do water changes.