Giant Oarfish

 Giant Oarfish

  • Scientific name: Regalecus glesne
  • Also know as: King of Herrings, Giant Ribbonfish, Earthquake Fish, Bank’s Ribbon-fish
  • Size: up to 60ft and 750lbs.
  • UK minimum size: N/a
  • UK shore caught record: N/a
  • IUCN Status
    • Global: LC (Least Concern)
    • Europe: LC (Least Concern)
  • Distribution: Has been recorded in all of the world’s seas and oceans, with the exception of the polar regions.
  • Feeds on: Although the mouth is toothless the giant oarfish can hunt and feed on fish, squid and jellyfish. Gills are adapted to also allow this species to filter-feed on plankton and tiny sea creatures.
  • Description: Long, slim, tapering scaleless body which is bright reflective silver, and sometimes flecked with black dots and marks. The pink dorsal fin runs the entire length of the body. Head consists of a toothless mouth and wide circular eyes. A bright pink crest of tendrils protrude from the top of the head and another two longer tendrils trail down from the gills.

The giant oarfish (or king of herrings as it is also known) is a very rare and unusual fish that is thought to exist in every major ocean and sea in the world. As this species lives most of its life at depths of 300 to 1000 metres it very rarely comes into contact with humans and as a result relatively little is known about its life-cycle or behaviour.


Giant oarfish has an extremely wide distribution, being found on a sporadic basis in temperate and tropical waters all around the world. They have been observed throughout the Pacific, Atlantic and Indian Oceans, and only appear to be absent from the cold arctic waters. In Europe they have been found as far north as the waters of Iceland and Norway, with their range continuing southwards into the Mediterranean and along the western coast of Africa.

A giant oarfish found in Tynemouth in June 2011. This oarfish was taken to a nearby Sea Life Centre.

Despite this wide distribution giant oarfish are a very rare species, with observations of this species being few and far between. Any sighting of a giant oarfish is likely to be of interest to marine biologists and the wider scientific community.

Size and Behaviour

Giant oarfish can grow to great lengths – in fact, they are the longest true fish in the world (but not the heaviest, that title belongs to the sunfish). Despite its size the giant oarfish is thought to be a passive fish and a relatively weak swimmer, plus its small, toothless mouth means it is harmless to humans. It feeds by hunting small fish, squid and possibly crustaceans, although it may also feed on plankton. It is thought that giant oarfish move by undulating their dorsal fin to provide propulsion, and the long tendrils that protrude from the gills may be used to sense for movement in the water, in a similar way to a lateral line. This YouTube video provides rare footage of a healthy and active giant oarfish in its natural environment. The fish appears to move through the water vertically, undulating its large dorsal fin as a means of propulsion. It is unknown why this creature moves in this way.

For reasons that still remain unknown to science giant oarfish sometimes wash up dead or dying onto shores. This can happen anywhere in the world with giant oarfish being found washed up in places as diverse as Kashiwajima, Japan, San Diego, USA and Seaham, North East England all finding dead oarfish washed up in recent years. Such is the rarity of giant oarfish that a washed up specimen is often reported in news outlets internationally.

Giant Oarfish
The 23 foot long, 300lb giant oarfish found by US Navy SEALS on the beach at Coronado, California.  This picture was used as the basis of a hoax to stir up anti-American sentiment around parts of Asia.

The above picture is from the pages of US Navy publication All Hands from 1997 and shows US Navy SEALS holding a 23 foot long, 300lb giant oarfish. The fish was found by Signalman 2nd Class Kevin Blake while conducting training exercises on the beach at Coronado, California. The fish was dead on discovery and, judging by its injuries, is thought to have been struck by the propeller of a ship. The remains of the fish were taken to the Scripp’s Institute of Oceanography at the University of California, San Diego for anatomical study. The head and a section of the giant oarfish’s body are still stored in preserving fluid at the Scripp’s Institute to this day. The photograph is also the basis of a hoax. Throughout south-east Asia there is the legend of the Phaya Nagá – a mythical sea serpent. This serpent is believed by locals to still rule the river and protect and look over those who earn their living from fishing or providing transport over the river. An unknown person took this 1997 photo, doctored the image to make it look older and conceal the injuries to the giant oarfish and wrote a caption in Vietnamese stating: Queen of Nagas seized by American Army at Mekhong River, Laos Military Base on June 27, 1973. This modified photo was then used to stir up anti-American feeling amongst the local people and copies of it can still be found in bars, restaurants and guesthouses in Laos and Vietnam.

The alternative name king of herrings comes from the fact that early sightings of this species in the 1700s observed the creature near to vast shoals of herring. The fishermen believed that the herrings were being led by this species and the tendrils on its head were a crown. In reality, the giant oarfish/king of herrings is not at all related to any herring or herring-like species and was probably preying on shoals of herring rather than leading them.

Human Interactions

Seaham Serpent - King of Herrings, Giant Oarfish
A man poses with a giant oarfish washed up on Seaham beach, County Durham in 2009. The fish was nicknamed the ‘Seaham Serpent’ by locals.

The vast majority of giant oarfish that are encountered by humans are washed up on beaches. It appears that this species comes into shallow water at the end of its life to die. Again the reasons for this are unknown. Since many of the giant oarfish washed up on British beaches are relatively small (by this species standards) others have speculated that these fish may be pushed into shallow water by tides and currents and become confused by the sudden changes in water pressure and end up beaching themselves. There have been several reports over the years of giant oarfish washing up on British beaches. In 1981 a giant oarfish washed up on the beach of Whitby in North Yorkshire, and in 2009 two were found on beaches in North East England, one in Tynemouth and one in Seaham (see picture). The only report of a giant oarfish being taken on a rod and line anywhere in the world also comes from near the North East, when Val Fletcher, 40, of Skinningrove, Cleveland, caught an 11ft, 140lb giant oarfish on a squid bait while fishing for cod at her local beach in February 2003. The fish was reeled in after a forty-minute battle. Scientists from the Natural History Museum in London hoped to preserve and display the giant oarfish, but unfortunately for them, Ms Fletcher tied the oarfish to a plank of wood to allow people to look at it and then chopped the oarfish into sections and put them in her freezer.

The International Union for the Conservation of Nature class giant oarfish as a species of Least Concern both in Europe and globally and state that there are no known major threats to this species.

Autotomy and Migration

Another mystery about the giant oarfish is why so many are found with the tail section apparently missing. At first it was thought that sharks or killer whales had attacked the giant oarfish, but this is now doubted. Assessment of a twelve-foot giant oarfish washed up in Sweden in 2010 (the first found in the country in 130 years) found that the snapped off tail section of the giant oarfish had no teeth marks in it, and the wound was old and the fish had clearly lived for a long time – possibly years – after losing its tail section. Additionally, all giant oarfish that have lost their tails appear to have been severed in the same section in the last third of the body, well clear of any internal organs, and a predators teeth marks have never been reported. Dr Tyson Roberts of the Smithsonian Tropical Research Institute, who is one of the world’s foremost experts on giant oarfish, believes that this species many have the ability to perform an act of autotomy – that is the ability to willingly cast off a body part (lizards are probably the most well-known species which do this when a predator has them caught by the tail). It is not known why giant oarfish cast off their tail section, but they seem able to happily live with their tail section missing and their spinal column exposed by losing this body part. Dr Roberts also put forward the theory that there were specific spawning grounds for the giant oarfish in the seas off Australia, New Zealand, South Africa and Florida. He went on to say that many giant oarfish which ended up dying in shallow water may in fact be trying to find their way to spawn and become lost and confused when they find a landmass in their way that they cannot get past. This would explain why the eastern coastline England and Scotland is something of a hotspot for giant oarfish sightings, as giant oarfish are possibly trying to find the most direct route to the Florida spawning ground but end up trapped in the North Sea and eventually become beached. Indeed, the first UK report of a giant oarfish was from Whitby in North Yorkshire in 1759 (see Historical Reports below).

Giant Oarfish Vienna
A model of a life-size giant oarfish at the Naturhistorisches (Natural History) Museum in Vienna, Austria.

‘Earthquake Fish’ and Recent Events

The giant oarfish is sometimes known as the earthquake fish as there is a long-standing belief in some parts of the world that finding a giant oarfish washed up on a beach is a sign that an earthquake is imminent. It is believed that underwater movement of tectonic plates (the precursor to an earthquake) leads to the death of oarfish, although there is little scientific evidence to back this up. In October 2013 an 18-foot giant oafish was washed up onto the beach of Santa Catalina Island, San Diego, California and six days later another 14-foot oarfish was washed up onto the beach of Oceanside, California – just 63 miles away. This incredibly rare event led to some local residents to believe that an earthquake may be on the way, but no significant earthquake was reported in the time immediately after the second oarfish was found. In 2016 a 16-foot giant oarfish was caught off the coast of Taiwan. Two small earthquakes had occurred earlier in the region, with local fishermen believing that the earthquakes had sent the oarfish into the upper levels of the sea where it was caught. In 2018 a number of giant oarfish washed up along the coastline of Japan, sparking fears that an earthquake could be imminent. However, no significant earthquakes were reported in the days and weeks after the oarfish was found.

Giant Oarfish
This giant oarfish was found washed up on a beach in Mexico.

In 2019 two Japanese universities produced research which they said definitively disproved the link between giant oarfish and earthquakes. Researchers from Tokai University and the University of Shizuoka looked at meteorological records going back to 1923 and matched instances of earthquakes to sightings and beachings of giant oarfish and similar species such as slender ribbonfish. They found that there was no correlation between earthquakes and the fish, and said that link between the two was down to nothing more than superstition.

Historical Reports of the Giant Oarfish

The giant oarfish was first described by the Norwegian biologist Peter Ascanius in 1772, after a giant oarfish was found near to the village of Glesvær in western Norway. However what is believed to be the first recorded sighting of a giant oarfish predates this, with the Annual Register recording a sea creature matching the description of a giant oarfish being found off the coast of Whitby in North Yorkshire in 1759. It is believed that many stories of sea serpents may in fact be accounted for by sightings of giant oarfish. In 1808 the body of a “serpent-like fish” was found washed onto the Scottish beach of Stronsay in the Orkney Islands after a storm. Reports from the time state that the ‘serpent’ was over fifty feet long, but as part of its tail was missing its true length may have been closer to seventy feet. It is highly likely that this was giant oarfish that had come into the shallow water to die. In 1859 the Victorian naturalist Albany Hancock and medical doctor Dennis Embleton provided a detailed description of a giant oarfish which had been found on the coast of Tyneside. The preserved body of this giant oarfish is reportedly still held in storage the archives of the Hancock Museum in Newcastle-upon-Tyne.

Giant Oarfish in Bermuda in 1860
A drawing of a ‘sea serpent’ – now through to be a giant oarfish – which washed up on a beach in Bermuda in 1860. The picture was published in Harper’s Weekly magazine.

The excerpt below is from a (reprinted) copy of the Proceedings of the Zoological Society of London from 1849 and describes scientists being baffled when the body of an unknown sea creature washed up on the beach at Filey Bay, North Yorkshire in 1796. From the diagram and description provided this was almost certainly a giant oarfish, which interestingly was also described as having “no tail”, adding further weight to the autotomy theory.

King of Herrings in the Proceedings of the Zoological Society of London

For further information on the giant oarfish click here for a short excerpt from a documentary, which includes footage of the first ever giant oarfish captured on tape.