male...3.5".... have not seen today... hope is still alive... i do have lots of rock... guess he is still hiding said:When I put mine in last night, watched him for about a minute, he seemed fine, checking the place out, I turned my back for 5 seconds, then I didnt see him again for the rest of the night. I was getting worried he had jumped and a cat made a snack of him. Today when I got home from work, he was out and about and having a grand time swimming in the current.