help id a hitch hiker


ill try to get a pic in a few mins but i got 2 things that look like porkupines sorry for bad spelling, 1 is a perpect circle and other is about 1 1/2 inch oblong any ideals?


most urchins grow pertty big (like more than 3 inch diameter) and they move like a bulldozer, will knock over small rock part (same size as them, maybe a little bigger than them) they will most likely not harm corals if they are those algae eating type, but they may munch on your corals when they are bored (hungry, and no more algae in the tank)