Echeneidae - remoras

Remoras are slender fishes and can be easily recognized by the oval sucking disk on top of their heads, which is actually a modification of a spinous dorsal fin. Remoras attach themselves to other vertebrates and objects, such as whales and dolphins, sharks, rays, billfishes, jacks, sea turtles, boats, floating debris, to name a few. Some are host-specific while others will attach to a wide variety of fishes or objects. They feed on small fishes, leftovers from the host, or parasites on the host's body. They've also been known to enter the host's gill cavity to hide from danger or to eat on parasites. They are not considered an important food fish, but they are sometimes used by native fishermen as "live hooks" to aid in line fishing. A line is tied around the fish's tail, and the fish is released into the water. When the remora attaches to another fish, the line is slowly reeled in.