The Black Demon of the Sea of Cortez

6/9/2025

by M.P. Pellicer | Stranger Than Fiction Stories
What predator could claim as prey a fully-grown, great white shark? There is only one that comes to mind, but you see it's supposed to be extinct. It is a prehistoric fish known as Carcharodon Megalodon, or as the sailors frequenting the Sea of Cortez have named it, El Demonio Negro (The Black Demon), and according to them it is still very much alive.

Imagine Megalodon in a modern-day marine aquarium

The Gulf of California known as the Sea of Cortez lies between the Baja Peninsula and Sonora. Throughout the years, those who have traversed these waters, whether for business or pleasure tell the tale of sighting a shark that measures approximately 50 feet. The sun glints on its black skin when it surfaces, and its huge tail churns the sea. It is large enough to overturn boats, swallow a pod of sea lions and attack a whale.

The stories of the sightings have passed through word of mouth, with no tangible proof of their existence, except for half-eaten whale carcasses that wash up on shore.

Based on a sighting in 2008, in these waters by sport fisherman, Erick Mack, Monster Quest sent a film crew the following year to hopefully capture the creature that Mack described as being 50 feet long, with dark skin, and an enormous flipper. It rocked his boat, and with a splash from its tail dove rapidly into the depths. An alternative explanation for the sighting, is that it's a hypermelanistic great white shark grown to its full length. This creature would be the opposite of an albino with too much melanin causing its skin to appear dark.

Others suggest it might have been a whale shark, which can reach lengths in excess of 40 feet. They are darker than great whites, and churn the ocean surface with their tails. However they are not predators.

Fishermen based in Guaymas, Sonora, Mexico, brought in 20 ft. great white shark that got caught in their nets and died.

The Gulf of California has its fair share of very large sharks. In 2012, fishermen found a dead great white shark entangled in nets they had set for flounder. It measured almost 20 feet and weighed 2,000 pounds. Despite its great size, this specimen still falls short of the description given for the Black Demon.

Sightings of what might be a Megalodon come from other parts of the world. In his book, Sharks and Rays of the Australian Seas (1963), marine biologist David G. Stead recounts a story dating back to 1918. He was visiting Port Stephens, off the coast of New South Wales (NSW), and he met with local crayfish fishermen who were Greek immigrants. They were from Broughton Island, and they refused to fish in the area. They described to him where they encountered a shark measuring over 115 feet, who destroyed their equipment and ate their crayfish pots, which measured over 3 feet across. It also snapped their mooring lines, and took a bite out of one of their boats. Having fished these seas for generations they claimed it was unlike any creature they had seen before. It was totally white and made the water "boil" with the motion of its body. They were sure it was not a whale.

Story of the encounter with a huge shark in NSW told to David Stead c. Jan. 1918

Some have posited what the men saw was an albino whale shark which was not recorded in NSW until 1936, and not seen in the Mediterranean Sea until 2021. However the behavior does not belong to a whale shark, which are filter feeders. Also the fishermen were familiar with great white sharks, and would have identified it as such if this is what they encountered.

Another theory is that the fishermen lied about the attack, because they lost the equipment during a recent monsoon storm, and since they probably leased the equipment they wanted to offset the blame.

David Stead wrote about another sighting in his book that was told to him in 1939. The author was J.S. Elkington who was a ship's captain. He said that in 1894 off Townsville, Queensland, Australia (possibly off the Great Barrier Reef), he was sitting in a 35 foot launch that had broken down. A shark approached the boat and stayed about 10 feet away for about 30 minutes. Its length was a few feet longer than the boat and was yellowish white in color. He was certain it was a great white and ruled out a basking shark.

Some believe that Elkington's sighting was a whale shark, and that he might have been influenced by a story about a great white supposedly captured off Port Fairy, Victoria, Australia that measured 36.5 foot.

In 1890, a large shark was captured at Townsville and when opened was found to contain portions of a man's legs. It was believed these were part of Captain Fowler who disappeared on December 26, 1889 in a boating accident. No exact measurement of this shark was given, only that it was described as "enormous".

The ship Eclipse had shark's teeth removed that went through metal and were stuck in the wooden hull c.1897

Pierre Clostermann in his 1969 book Des Poissons Grands (Such Big Fish), described an attack by an enormous great white. The ship Rachel Cohen was off Timor in March 1954, when it was rocked by an unseen collision on a stormy night. The ship returned to Adelaide for repairs and 17 teeth were lodged in the wooden keel. The size of the teeth were 3.9 inches and 3.1 inches at the base. The bite was an arc near the propeller shaft, which was bent from the force. Using the bite it indicated the fish measured 78.7 feet.

However the last reference to the Rachel Cohen, which was part of the Royal Dutch Mail line, predated the incident by decades. The boat was used to carry food supplies from Darwin to the people in isolated districts. In January, 1924 a storm blew in, and the ship's anchors began to drag and moved her toward the creek. A few days later the 53-year-old boat burned down, after caretakers had started a fire in a tin to ward off sandflies and mosquitoes. They fell asleep and woke after the fire had a good hold.

Based on this information the story described by Clostermann is not accurate.

In 1897, the Eclipse was docked for refitting at Birkenhead when shark teeth were removed from the copper plating on the hull. There was no information as to how many teeth, their measurement and what species they belonged to. Some believe this incident was retold in 1926, in which the ship's name was changed to the Rachel Cohen, and Clostermann made up a tale using an amalgamation of all the stories.

In the 1960s along the outer edge of Australia’s Great Barrier Reef, an 85-foot ship experienced engine trouble, which forced it to weigh anchor for repairs. Although the men subsequently refused to openly report what they had seen for fear of public ridicule, the captain and his crew later told friends of sighting an immense shark as it moved slowly past their ship. Whitish in color, they were awed by its size. It was as long, if not longer, than their boat! Experienced men of the sea, they too were certain the creature was not a whale.. --- Let’s Go Fossil Shark Tooth Hunting (Cartnell, B.C.)

Zane Grey poses with a mako shark he landed. c.1926

During the 1920s, game-fishing novelist Zane Grey frequented New Zealand and broke several world fishing records, however he claimed to have an encounter with a "man-eating monster of the South Pacific."

He told of an encounter he had in June, 1928 in the Rangiroa atoll in the South Pacific. He was accompanied by his son Loren. Also accompanying him were several boats and crewmen. They were reeling in yellowfin tuna, when a large shark surfaced toward them. It passed under the boats, ignoring the tuna. It was yellowish-green with a few white spots, with a square head and large pectoral fins. The tail end of the body was thinner. Zane estimate it to be 8 feet wide and at least 35-40 feet long.

Loren wrote about it in the book Shark: The Killer of the Deep (1976). By then his father had passed away. In his retelling the year was 1933, and they were on board the S.S. Maunganui. He realized the spotting on the shark were barnacles. Its tail protruded out of the water, it had a round head that measured 10-12 feet in width and it was about 40-50 feet in length.

Neither Zane or Loren believed it was a Megalodon. They were not certain what the species was but they were certain it was not a whale shark.

Some have argued the fish's behavior is contradictory to a shark which would have gone after the hooked fishes.

Photographer Kimberly Jeffries with one of the biggest great white on record - Deep Blue who is about 20 feet long and weighs over 2 tons c.2019

In 2003, a 9 foot, female great white shark was tagged by researchers in Australia. Several months later the tag washed up on a shore 2.5 miles from where the shark was released. When they checked the tracking device, it showed the animal had suddenly plunged 1,900 feet down into the ocean. Then the instrumentation registered a spike in heat, equivalent to being inside a digestive system. It stayed at this temperature for several days. Then there was an occasional rise to the surface before descending again. Then the tracker washed onshore.

The researchers surmised this shark had been eaten by a larger great white shark, however its internal temperature puzzled them. It appeared too low for a killer whale, too high for another shark, unless it was "massive". A "colossal cannibal great white shark" is thought to be the culprit. It's estimated to be over 16 feet long and weigh two tons. Again this is just a theory.

In February 2024, a dead great white shark estimated at 15 feet in length washed up on a Navarre Beach in Florida's Panhandle. A necropsy found the great white was a 30-year-old female that measured 15.1 feet. She was not pregnant because she was too young. There were no signs of trauma on the carcass.

In January, 2025, a male, great white shark nicknamed "Contender" swimming off Florida's east coast was tagged by OCEARCH. He weighs 1,653 pounds and measures 13 feet and 9 inches. This is the largest male shark recorded by OCEARCH.

Sir John Hawkins introduced the word "shark" into English lexicon based on Maya dialect

In 1567, Sir John Hawkins an English naval commander, privateer and sea merchant sailed along the coast of the Yucatan Peninsula. It was in these waters that his crew saw large carnivorous fish unknown to them. They asked the indigenous Maya its name, and they were told, "xoc". Upon returning to England in 1569, they added the word "shark" to the English lexicon.

Sir John was born to a prominent family of ship builders and captains in the naval port of Plymouth in Devon. His father was the first man to sail to Brazil, and his cousin was Sir Francis Drake. This was a man who grew up in a household that was familiar with sightings of large fish, and this was something he had not seen before, or heard described.

Megalodon tooth

Stories of whales attacked and maimed by a predator also point to the existence of Megalodon since this was the type of prey it consumed, as well as seals, sea lions, giant sea turtles, dolphins, porpoises and sea cows. Whale fossils show the marks of very large shark teeth which belonged to Megalodon.

In 2019, a photographer and a cave expert discovered three different shark teeth in the Xoc cenote in Madeira, Mexico. This area was underwater millions of years ago. The teeth belong to the ancient megalodon, shortfin Mako and sawshark. The question is did megalodon survive millions of years beyond what is believed by most experts?

Megalodon teeth found by the HMS Challenger during an expedition (1872-1876) in the South Pacific, were dated in 1959 by the zoologist Wladimir Tschernezky to be around 11,000 to 24,000 years old. This would indicate this shark disappeared must more recently then believed.

Tales of enormous sharks that are considered monsters have existed for hundreds of years

There were other shark stories which could also lead to the belief in the demon shark.

In 1851, a 17 foot shark was caught off the Florida coast in Apalachicola by the ship Constantine. The ship's log did not specify what type of shark, however when they opened it up they found an entire thigh, leg, foot and part of the other thigh, the knee, a portion of the leg and one of the shoulder belonging to a man. It was undigested, which indicated the shark had recently eaten him.

That same year a shark was taken in the Sound, which was found to have the remains of two boys inside it. Two lads who had been swimming in the bay had gone missing, and it's believed this is what happened to them.

In 1932, a giant shark ripped the nets and broke a ship's rudder. It was a tuna clipper that left San Diego and had to be towed in. The captain of the California said the shark became entangled in sardine nets and ripped it to shreds. One fisherman said it was 50 feet long, but others scaled it down to 30 feet. After damaging the vessel, the fish disappeared.

In 1934, off Coquimbo, Chile a giant shark terrorized beach goers. It was believed he had "devoured" a soldier who fell into the sea accidentally. The shark attacked several boats and damaged them severely.

This has fueled claims that megalodon could remain elusive in the depths, similar to the megamouth shark which was discovered in 1976. This shark reaches a length of around 26–30 feet, and mostly eats plankton, and somehow had remained unknown well into the 20th century.

The majority of the earth's surface is made up of oceans, with depths that remain unexplored, including what swims in the inky darkness so many feet from the light of the sun. Considering our lack of knowledge, the possibility that this giant predator still exists is not beyond belief.