A megamouth shark caught off the coast of Japan. - Photo courtesy of Sergei Boka (CCBY-SA 4.0).
GIVEN how vast and deep our oceans are, it is logical to deduce that many species remain undiscovered until chance and technological advancement leads to an encounter or two – and with the discovery of new lifeforms, tall tales often emerge about how they were discovered.
Ever since the mid-1970s, it has been claimed that a rare species of shark called the megamouth was discovered when it died trying to swallow an anchor of a US Navy research ship.
Is there any truth to this, or is it a salty seafarers story?
Verdict:
PARTIALLY TRUE
While no official accounts say that the shark was actually found trying to swallow the anchor, sources such as the Hawaii state government's Department of Land and Natural Resources do not deny that the anchor of a US Navy ship was in fact involved.
In a post on its official website, the department said that the ship in question was operating in deep waters off the northernmost spot on O‘ahu when the megamouth shark was discovered on November 15, 1976.
The Department said that the ship had lowered two large parachute-like anchors to a depth of 152m and found the 4.5m-long shark entangled around one of them when both were pulled back up, adding that the shark did not survive.
"The 1,500 pound (680kg) shark was finally brought aboard the ship and transported to a Navy lab at Kane‘ohe Bay.
"Local marine biologists were summoned to the site, and calls were made to shark specialists around the country.
"None had ever seen or heard of such a shark," it added.
The Department said that the shark was described and named by then-Waikiki Aquarium director Leighton Taylor as he was one of the first on the scene and added that the press immediately picked up on his nickname "megamouth", chosen because its mouth was almost a metre wide.
"It would take another seven years before the fish was formally described scientifically. It belonged to a new family (and therefore a new genus and species), and Taylor named it Megachasma pelagios, Greek for giant yawner of the open sea," added the Department.
As for what it eats to need such a mouth, one need not fear as it eats tiny shrimp and plankton like the whale shark and basking shark – not people.
"It was placed in the order Lamniformes, which includes the basking shark, but also the white shark, threshers, makos, and sand tigers," said the Department.
The Department added that scientists have since found that megamouth sharks seem to be a deep water species, possibly following the deep scattering layer of vertically migrating plankton which come closer to the surface at night.
"As of the end of 2003, 18 megamouths had been found, and there was an unconfirmed report of a May 26, 2003 sighting near Dana Point, CA. Megamouth I (the holotype, or first one described) is still held in the Bishop Museum icthyology collection in Honolulu," it said.
References:
1. https://dlnr.hawaii.gov/sharks/hawaii-sharks/discovering-megamouth/
2. https://www.wildlifeonline.me.uk/animals/species/the-megamouth-shark
3. https://ocean.si.edu/ocean-life/sharks-rays/original-megamouth