oarfish

The oarfish is a strange-looking deep-sea fish found in warm parts of the Atlantic, Pacific, and Indian oceans. It grows up to 9 m/30 ft long. Its silver body is compressed and the dorsal fin forms a manelike crest behind the head.

Any of a group of deep-sea bony fishes, found in warm parts of the Atlantic, Pacific, and Indian oceans. Oarfish are large, up to 9 m/30 ft long, elongated, and compressed, with a fin along the back and a manelike crest behind the head. They have a small mouth, no teeth or scales, and large eyes. They are often described as sea serpents. (Genus Regalecidae.)