I never thought to mention that mine is in a brackish tank and has been in for about a year. Mine has no problems eating guppies and ghost shrimp. I hope I will not have long term problems in the future because I also have a Gymnothorax tile, toad fish, and a red scat. So far all are getting along. The moray and pinky are sharing the root ornament peacefully. To further add from guppy's reply mine does have a round fin at the end of his tail.