I have 2 black long spine urchins in my tank. Both have been in the same tank for 2+yrs and there has been little added or taken away in that time. I got them both at the same time and both were appx 1 1/2 - 2 inches at the time. They grew to be around 8 inches at the tips of their spines and have been great at dealing with bubble algae.
The issue is that over the last 2-3 months one of them has lost almost all of its long spines, while the other is still as "spiny" as always. The one that has lost it's spines still moves around the tank foraging on algae and such, and shows no signs of disease or injury. It still tries to turn it's few remaining spines in defense if anything goes near it and, other than it's physical appearance, acts normal. Does anyone know what would cause this or where I could read more on the species in captivity?
The issue is that over the last 2-3 months one of them has lost almost all of its long spines, while the other is still as "spiny" as always. The one that has lost it's spines still moves around the tank foraging on algae and such, and shows no signs of disease or injury. It still tries to turn it's few remaining spines in defense if anything goes near it and, other than it's physical appearance, acts normal. Does anyone know what would cause this or where I could read more on the species in captivity?
