Alex Mustard / A fisherman swims down to touch the statue of Christ Of The Abyss (Cristo degli abissi) for good fortune, in the Marine Protected Area of Portofino (Area Marina Protetta, Portofino), Liguria, Italy. M...

Paul D Stewart / Illustration of Giant Octopus (Octopus dofleini) attacking a ship, 1815 copperplate engraving from Bertuch's 'Bilderbuch fur kinder' 16 plate 5. with contemporary colour. 'Colosal Polypus' (octopus) a...

Robert Smith / Diver exploring a freshwater Limestone sinkhole / Cenote called 'The Pit' - a traverse to 'The Blue Abyss' with stalactites and stalagmites, Tulum, Quintana Roo, Mexico, September 2008. Model released

Norbert Wu / Humpback Anglerfish (Melanocetus johnsoni) deep sea species showing bioluminescent fishing pole attracts deep sea prey, California

Norbert Wu / Devil Angler (Linophryne indica) fish, deep sea species showing large female with dwarf male attached

Norbert Wu / Humpback Anglerfish (Melanocetus johnsoni) deep sea species showing fishing pole with bioluminescent lure used to attract prey

Norbert Wu / Lavenberg's Gulper-eel (Saccopharynx lavenbergi) deep sea species with hinged mouth swings wide open to accommodate large prey, deep sea, Guadalupe Island

Norbert Wu / Viperfish (Chauliodus sp) attacking Mysids, luring prey with photophores, deep sea

Norbert Wu / Viperfish (Chauliodus sloani) light organs in mouth and all along body, southeastern Pacific, deep sea

Norbert Wu / California Bigeye Octopus (Octopus californicus) deep sea species swimming, California

Norbert Wu / Australian Ghost Shark (Callorhinchus milii) trunk-like snout detects prey in sea bottom, primitive fish relative to sharks, lives in the deep sea, New Zealand

Norbert Wu / Spotted Ratfish (Hydrolagus colliei) deep sea fish, Monterey, California