Nick Hawkins / Ocean sunfish (Mola mola) off Halifax, Nova Scotia, Canada. July.

Sue Daly / Ocean sunfish (Mola mola) , Sark, British Channel Islands, UK, September.

Franco Banfi,Franco Banfi / Ocean Sunfish (Mola Mola) with Longfinned bannerfish (Heniochus acuminatus) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Hiroya Minakuchi / Ocean Sunfish (Mola mola) swimming near surface, Portugal

Sergio Hanquet / Ocean sunfish (Mola mola) and Pilot fish (Naucrates sp). Tenerife, Canary Islands.

Sergio Hanquet / Ocean sunfish (Mola mola) and Pilot fish (Naucrates sp). Tenerife, Canary Islands.

Sergio Hanquet / Ocean sunfich (Mola mola) at sea with pilot fish. Sp: Pez Luna, Pejeluna - fr: Poisson lune.

Nick Hawkins / Ocean sunfish (Mola mola) and prey, moon jellyfish (Aurelia aurita) off Halifax, Nova Scotia, Canada. July.

Nick Hawkins / Ocean sunfish (Mola mola) and prey, moon jellyfish (Aurelia aurita) off Halifax, Nova Scotia, Canada. July.

Nick Hawkins / Ocean sunfish (Mola mola) off Halifax, Nova Scotia, Canada. July.

Nick Hawkins / Ocean sunfish (Mola mola) off Halifax, Nova Scotia, Canada. July.

Ralph Pace / California Sea Lion (Zalophus californianus) feeding on Ocean Sunfish (Mola mola), San Diego, California

Ralph Pace / Ocean Sunfish (Mola mola), San Diego, California

Chase Dekker / Ocean Sunfish (Mola mola) near surface, Monterey Bay, California

Richard Robinson / Bump-head sunfish (Mola alexandrini) offshore, Northern New Zealand.

Richard Robinson / Bump-head sunfish (Mola alexandrini) offshore, Northern New Zealand.

Nick Hawkins / Ocean sunfish (Mola mola) off Halifax, Nova Scotia, Canada. July.

Nick Hawkins / Ocean sunfish (Mola mola) off Halifax, Nova Scotia, Canada. July.

Tony Wu / Parasitic copepod in the Caligidae family (possibly Caligus sp. or Lepeoptheirus sp.),that was associated with a Ocean sunfish (Mola mola) ocean sunfish. The long appendage visible at the rear end is...

Tony Wu / Ocean sunfish (Mola mola) close up whilst relaxing at waters surface, South Africa, Atlantic Ocean.

Tony Wu / Ocean sunfish (Mola mola), basking at waters surface, South Africa, Atlantic Ocean.

Richard Herrmann / Bat Star (Asterina miniata) group and sea snails feeding on Ocean Sunfish (Mola mola) that was killed by California Sea Lion (Zalophus californianus), Monterey Bay, California

Sue Daly / Ocean sunfish (Mola mola) , Sark, British Channel Islands, UK, September.

Pete Oxford / Southern Ocean Sunfish (Mola ramsayi), Punta Vicente Roca, Isabela Island, Galapagos Islands, Ecuador

Alex Mustard / Diver encounters a large sunfish (Mola mola), the world's heaviest bony fish. Tulamben, Bali, Indonesia. Java Sea Model released

Chris & Monique Fallows / Sunfish (Mola mola) at Cape Point, South Africa.

Chris & Monique Fallows / Sunfish (Mola mola) at Cape Point, South Africa.

Chris & Monique Fallows / Sunfish (Mola mola) at Cape Point, South Africa.

Alex Mustard / Ocean sunfish (Mola mola) stranded on a British beach. Titchwell, Norfolk, England, United Kingdom. North Sea, December 2015.

Richard Herrmann / California Sea Lion (Zalophus californianus) feeding on Ocean Sunfish (Mola mola), Nine Mile Bank, San Diego, California. Sequence 3 of 4

Richard Herrmann / California Sea Lion (Zalophus californianus) feeding on Ocean Sunfish (Mola mola), Nine Mile Bank, San Diego, California. Sequence 2 of 4

Richard Herrmann / Ocean Sunfish (Mola mola) group gather under floating kelp paddy, Nine Mile Bank, San Diego, California

Alex Mustard / Sunfish (Mola mola) basking at the surface on summer's day. Penzance, Cornwall, England, British Isles, August. North East Atlantic Ocean.

Michael Pitts / Komodo Dragon (Varanus komodensis) on the seashore with washed up Oceanic sunfish (Mola mola) Komodo Island. Indonesia

Franco Banfi / Scuba diver with Ocean Sunfish (Mola mola) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Franco Banfi / Ocean Sunfish (Mola mola) with Longfin bannerfish (Heniochus acuminatus) cleaning the skin, Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Franco Banfi / Scuba divers with Ocean Sunfish (Mola mola) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Franco Banfi / Ocean Sunfish (Mola Mola) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Franco Banfi / Ocean Sunfish (Mola Mola) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Franco Banfi / Scuba diver photographing Ocean Sunfish (Mola Mola) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Franco Banfi / Ocean Sunfish (Mola Mola) swimming through a shoal of different fish including Longfin Bannerfish (Heniochus acuminatus) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Franco Banfi / Ocean Sunfish (Mola Mola) with Longfin bannerfish (Heniochus acuminatus) Crystal Bay, Nusa Penida, Bali Island, Indonesia, Pacific Ocean

Hiroya Minakuchi / Ocean Sunfish (Mola mola) swimming near water surface, Portugal

Nick Upton / Ocean sunfish (Mola mola) swimming just below Mediterrean sea surface near Marseille, France, May.

Suzi Eszterhas / Ocean Sunfish (Mola mola) near surface, Baja California, Mexico

Richard Herrmann / Ocean Sunfish (Mola mola) and Giant Kelp (Macrocystis pyrifera), San Diego, California

Richard Herrmann / Ocean Sunfish (Mola mola) and Giant Kelp (Macrocystis pyrifera) paddy, San Diego, California

Richard Herrmann / Ocean Sunfish (Mola mola) pair near kelp, San Diego, California

Richard Herrmann / Ocean Sunfish (Mola mola) under drifting Giant Kelp (Macrocystis pyrifera) paddy, San Diego, California

Richard Herrmann / Ocean Sunfish (Mola mola) under drifting Giant Kelp (Macrocystis pyrifera) paddy, San Diego, California

Fred Bavendam / Ocean Sunfish (Mola mola) swimming with smaller fish, Indonesia

Hiroya Minakuchi / Threadsail Filefish (Stephanolepis cirrhifer) cleaning Ocean Sunfish (Mola mola), Azores, Portugal

Hiroya Minakuchi / Ocean Sunfish (Mola mola) portrait, Portugal

Norbert Wu / Ocean Sunfish (Mola mola) larvae

Ralph Pace / Bat Star (Asterina miniata) feeding on juvenile Ocean Sunfish (Mola mola) carcass, Monterey, California

Ralph Pace / Ocean Sunfish (Mola mola), San Diego, California

Ralph Pace / California Sea Lion (Zalophus californianus) feeding on Ocean Sunfish (Mola mola), San Diego, California

Ralph Pace / Ocean Sunfish (Mola mola) with scar from gillnet, Hawaii

Ralph Pace / Ocean Sunfish (Mola mola), San Diego, California

Richard Herrmann / Bat Star (Asterina miniata) group and sea snails feeding on Ocean Sunfish (Mola mola) that was killed by California Sea Lion (Zalophus californianus), Monterey Bay, California

Richard Herrmann / California Sea Lion (Zalophus californianus) bull predating juvenile Ocean Sunfish (Mola mola) with gull looking to scavenge, Monterey Bay, California

Pete Oxford / Southern Ocean Sunfish (Mola ramsayi), Punta Vicente Roca, Isabela Island, Galapagos Islands, Ecuador

Pete Oxford / Southern Ocean Sunfish (Mola ramsayi), Punta Vicente Roca, Isabela Island, Galapagos Islands, Ecuador

Pete Oxford / Southern Ocean Sunfish (Mola ramsayi), Punta Vicente Roca, Isabela Island, Galapagos Islands, Ecuador

Richard Herrmann / Ocean Sunfish (Mola mola) predating By-the-wind Sailor (Velella velella), San Diego, California, sequence 4 of 4

Richard Herrmann / Ocean Sunfish (Mola mola) predating By-the-wind Sailor (Velella velella), San Diego, California, sequence 3 of 4

Richard Herrmann / Ocean Sunfish (Mola mola) predating By-the-wind Sailor (Velella velella), San Diego, California, sequence 2 of 4

Richard Herrmann / Ocean Sunfish (Mola mola) predating By-the-wind Sailor (Velella velella), San Diego, California, sequence 1 of 4

Richard Herrmann / California Sea Lion (Zalophus californianus) feeding on Ocean Sunfish (Mola mola), Nine Mile Bank, San Diego, California. Sequence 4 of 4

Richard Herrmann / California Sea Lion (Zalophus californianus) catching Ocean Sunfish (Mola mola), Nine Mile Bank, San Diego, California. Sequence 1 of 4

Hiroya Minakuchi / Threadsail Filefish (Stephanolepis cirrhifer) cleaning Ocean Sunfish (Mola mola), Azores, Portugal

Hiroya Minakuchi / Atlantic Spotted Dolphin (Stenella frontalis) pair, Bahamas, Caribbean Sea

Martin Camm / Carwardine / Illustration of Ocean Sunfish (Mola mola), Molidae; heaviest bony fish in world (Wildlife Art Company).

Alex Mustard / Ocean sunfish (Mola mola) swims beneath the surface of the English Channel with reflection. Penzance, Cornwall, England, United Kingdom. British Isles. North East Atlantic Ocean.

Chris Gomersall / Ocean sunfish (Mola mola) seen underwater, by the isle of Barra in the Western Isles, Scotland. A rare visitor to British waters.