I was snorkeling in the channel between Deep Blue Resort and the lower lagoon trying to add a checkered puffer to my life list (which I got) when I saw this strange guy. His pectoral fins were long and flexible kind of like gummy arms. About 2-3 feet of water, 3-4 inches (7.5-10 cm) in length. Habitat brackish mangrove lagoon. He ducked down in the silt after I took the shot. Not the only strange and new fish I saw on this dive--but one I managed to get a pic of. Very rich and diverse fish down here.