The First Megamouth Shark, Caught by US Navy Vessel AFB-14 off Kahuku Point, Oʻahu

The Naval Undersea Center ran a Hawaii Laboratory at Kāneʻohe Bay. In November 1976 its vessel, AFB-14, was holding position about 42 km northeast of Kahuku Point, Oʻahu. The bottom lay approximately 4600 m below. Two large parachutes served as sea anchors. Hugh Gallagher, a civilian contractor aboard, later said it was a classified Navy sonar operation. No official source confirms that.

15 November 1976. The crew winched the parachutes up. One of them was not empty. A huge shark was tangled inside, caught where the anchor hung at about 165 m. Gallagher said it had swallowed the parachute. Another account says its teeth snagged on the anchor. The crew saw at once that it was unusual. They brought it aboard "with much difficulty".

It was an adult male, 4.46 m long and 750 kg. Its body and fins were soft and flabby. Its head was long, wide and bulbous. The mouth was about 3 ft wide and held more than 400 tiny teeth. Fresh, it showed "a bright silvery lining punctuated by small circular porelike structures". The black irises nearly filled the eyes. Nobody saw it swim. The shark died.

The animal was taken to the Navy facility at Kāneʻohe Bay and tied alongside the dock overnight. A Navy crane lifted it by the tail. The caudal fin broke off, and divers had to recover the body from the water. Lt. Linda Hubble, John Hobbs and Rick Kahakini were credited with recovering it and recognising the find. Paul Meyers filmed its preservation on 16 mm.

Shark specialists across the country were consulted. None had seen or heard of such a shark. The press named it megamouth, and the Associated Press carried the story nationally.

Dr Leighton R. Taylor, director of the Waikiki Aquarium, was one of the first biologists on the scene. With Leonard J. V. Compagno and Paul J. Struhsaker, he published the formal description on 6 July 1983. They called it Megachasma pelagios, from the Greek for "yawning hole, open mouth" and "of the open sea". A new species. A new genus. A new family. It was only the third plankton-eating shark known, after the whale shark and the basking shark. The authors judged that "M. pelagios is a slow, weak swimmer", perhaps "slowly swimming through schools of euphausiid shrimp" when it met the anchor. They wondered whether the silvery spots were light organs. A 2020 study found the species does not produce light.

The long wait invited mischief. Richard Ellis and John McCosker reportedly assembled a fake Japanese journal article, salted with megamouth photos, a map and an English abstract. It made a rival team look ready to publish first. Taylor had it translated, found nothing about the shark, and finished his own paper.

The holotype, BPBM 22730, rests at the Bernice P. Bishop Museum in Honolulu. The second specimen came eight years later, off Catalina Island, California. By 25 March 2025 there were 296 records worldwide. On 30 November 2011 a cast of the 1976 animal went on display at Loren Coleman's International Cryptozoology Museum in Portland, Maine. Karl Shuker calls the shark "ethno-unknown" and argues that by strict convention "the megamouth shark was never a cryptid." Either way, an unknown giant came up from the deep. And it was real.