The Longspine Urchin is a valued cleanupcrew addition sold instore here in Columbus, Ohio. It acts as a algaeeating urchin, even coralline, helping reduce maintenance and improve water quality. Stock 1 per 40 gal in a balanced reef or fishonly system for best results. Difficulty: EasyModerate. May topple loose coralssecure frags. Dripacclimate and maintain stable salinity for longterm health.