I'm planning on getting my rescue diver certification in about a month, and I was thinking that I'd like to take something from the local coastline while diving for my tank. I recently got a pencil urchin to help mow down some algae and it is clearly the best member of my CUC so far. So I want to try and collect a purple urchin (Strongylocentrotus purpuratus) from the coast and put it my tank. I figure this won't be an environmental issue because ever since we hunted the sea otter population to near extinction, the urchins have been growing out of control and damaging out kelp forests, so it shouldn't hurt anything to take one for my aquarium. However, I'm not sure if an urchin that lives in 50F water can survive at 75F. I know that local anemones and crabs can survive at 70F because one of the teaching labs at UC Berkeley has a room temp aquarium that has kept these creatures alive for years. Does anyone have any thoughts about this? Of course I will be careful to test whether these urchins are reef safe before dropping one in my display.