Q: We found this unusual fish carcass floating several miles off Los Barriles in the Sea of Cortez. The dorsal fin had a tall, spine-like appearance and the pectoral fins were huge and strong, like flippers. The long, knife-like tail had a feathery fringe on top and bottom. The snout ended in a point and the skin was smooth and rubbery. None of the locals could identify this fish. Any ideas what it might be? - Ernest and Janine Newkirk, Montara, California A: Sure. It's a longnose chimaera (Harriotta raleighana), in the family Rhinochimaeridae. An ancient group of cartilaginous fishes, many chimaeras live at great depths, some over 7,000 feet. About 35 species of chimaeras exist around the world, but only three are known from your area, including the spotted ratfish and black ratfish. The longnose chimaera, with its long, spearlike snout, is known from Southern California, the Gulf of California and south Baja. Occasionally people catch chimaeras in sablefish traps set in very deep water or find their long, spindle-shaped egg cases off Southern California. Chimaeras are distinguished by their long, tapering tails, slippery, unscaled skin, two dorsal fins - the first with a spine and the second long and low - and gill flaps covering the gills. Their teeth - two upper plates and one lower plate - project from the mouth like rat's incisors. Weak swimmers, chimaeras feed on invertebrates and small fishes. Some species grow up to 5 feet long.