mega-mouth shark (megachasma pelagios)
The megamouth shark is an extremely rare species of deepwater shark. Since being discovered in 1976, only a few megamouth sharks have been seen with 44 specimens known to have been caught or sighted as of 2009. Like the basking shark and whale shark, it is a filter feeder, and swims with its enormous mouth wide open, filtering water for plankton and jellyfish. It is distinctive for its large head with rubbery lips. It is so unlike any other type of shark that it is classified in its own family Megachasmidae. The appearance of the megamouth is distinctive, but little else is known about it. It has a generally brownish-blackish color on top and white underneath, and an asymmetrical tail with a long upper lobe, similar to the thresher shark. The interior of its gill slits are lined with finger-like gill rakers that capture its food. A relatively poor swimmer, the megamouth has a soft, flabby body and lacks keels. Megamouths are very large sharks, able to grow to 18 ft in length. Weights of up to 2,680 lb have been reported. As their name implies, megamouths have a large mouth with small teeth, and a broad, rounded snout, causing observers to occasionally mistake megamouth for a young orca. The mouth is surrounded by luminous photophores, which may act as a lure for plankton or small fish.
