I've had mine for 2 weeks now. He's a character. Very fun to watch. He's got attitude. He eats long hair as well as the flat algae. He likes to hang around and scope out the place until he's hungry then he'll start to graze. He goes at it until he's had enough. Then he perches on a rock and watches everything. I've not seen him bother anything else. He and my very agressive possesive maroon clown fish (Joker) have stand off's every now but it's only when he gets too close to Jokers den. I haven't found any teeth/bite marks on Joker, yet. He has teeth and that's how he scrapes the algae off the rocks. He also likes coralline algae when there isn't enough green. But he much prefers the green stuff. Between him, my emerald crab, hermits and snails my tanks algae is definately in check.