---
title: "What the sources say about the Giant Oarfish | AnimalTracks.wiki"
description: "46 claims from the Giant Oarfish profile, each beside the words of the source that backs it."
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# What the sources say about the Giant Oarfish (*Regalecus glesne*)

> 46 claims from the Giant Oarfish profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Giant Oarfish](https://animaltracks.wiki/animals/giant-oarfish/)

## Oarfish, Regalecus glesne. Australian Museum, 2021.

https://australian.museum/learn/animals/fishes/oarfish-regalecus-glesne/

| The page says | The source says |
| :--- | :--- |
| reliably documented to 8 meters | reliably documented to grow to 8 m in length |
| Open ocean in tropical and temperate seas worldwide | The Oarfish is found worldwide in all tropical and temperate marine waters. |
| reports of it eating other invertebrates and fish are yet to be validated | Reports that the species feeds on invertebrates and fishes are yet to be validated. |
| The giant oarfish has been reliably documented to 8 meters (26 feet) | It has a ribbon-like body that has been reliably documented to grow to 8 m in length (note: 26 feet, converted from 8 m) |
| Fish up to 17 meters have been reported | specimens up to 17 m in length have been reported |
| The giant oarfish is found worldwide in tropical and temperate seas | The Oarfish is found worldwide in all tropical and temperate marine waters. |
| Its confirmed diet is krill | All verified cases of stomach contents consisted of krill (euphausiid shrimps). |
| Reports of it also eating other invertebrates and fish have not been confirmed | Reports that the species feeds on invertebrates and fishes are yet to be validated. |
| The giant oarfish has been reliably documented to grow to 8 meters (26 feet) long, though specimens up to 17 meters (about 56 feet) have been reported | reliably documented to grow to 8 m in length, however specimens up to 17 m in length have been reported (note: 26 feet and 56 feet converted from 8 m and 17 m) |

## Regalecus glesne (Oarfish). Florida Museum of Natural History, Ichthyology, 2025.

https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/regalecus-glesne/

| The page says | The source says |
| :--- | :--- |
| with a red dorsal fin along its whole length | The dorsal fin originates just above the relatively small eyes, running the entire length of the fish. It is distinctly colored, ranging from pinkish to cardinal red. (note: "red" for the source's "pinkish to cardinal red") |
| seen swimming upright in the open ocean | An oceanic species ... It has also been observed swimming in a vertical position |
| more typically down to about 200 meters, though reported as deep as 1,000 meters | An oceanic species, the oarfish is found living at great depths to 3,280 feet (1,000 m) but more typically to depths of 656 feet (200 m). (note: "reported" is weaker than the source's "found" on purpose: five-2013 puts the deepest verified record at 463-492 m) |
| Krill, strained from the water with specially evolved gill rakers | Oarfish feed on plankton, crustaceans, and squid by straining them from the water column using specially evolved gill rakes located in the mouth. One specimen caught off the coast of California contained a large volume (10,000 individuals) of krill (euphausids). (note: krill is au-museum-oarfish's only verified stomach content, claimed below; gill "rakes" is the source's spelling of gill rakers) |
| Swims with its body held straight by rippling a dorsal fin that runs its whole length | The oarfish swims by undulating its long dorsal fin while its body remains straight ... The dorsal fin originates just above the relatively small eyes, running the entire length of the fish. |
| has been seen swimming upright, which is believed to be how it searches for prey | It has also been observed swimming in a vertical position in what is believed to be a method that the oarfish searches for prey items. |
| keeps its long body straight and swims by rippling its red dorsal fin | The oarfish swims by undulating its long dorsal fin while its body remains straight ... It is distinctly colored, ranging from pinkish to cardinal red. (note: "red" for the source's "pinkish to cardinal red") |
| an "amiiform" swimming style | which is knows as an amiiform mode of swimming |
| It has also been seen swimming upright, which is believed to be how it searches for prey | It has also been observed swimming in a vertical position in what is believed to be a method that the oarfish searches for prey items. |
| That dorsal fin runs the entire length of its body in roughly 400 rays, with the first ten to twelve stretched into a trailing, spotted crest | The dorsal fin originates just above the relatively small eyes, running the entire length of the fish ... Consisting of approximately 400 dorsal fin rays, the first 10-12 are elongated forming a trailing crest with reddish spots and flaps of skin on the tip of each ray. |
| the Guinness Book of World Records considers it the longest bony fish alive in modern times | It is considered the longest bony fish alive in modern times by the Guinness Book of World Records. |
| though it is more commonly seen at about 3 meters (10 feet) | more commonly observed at lengths of approximately 10 feet (300 cm) total length (note: 3 meters, converted from the source's 10 feet (300 cm)) |
| The maximum published weight for the species is 272 kilograms (600 pounds) | The maximum published weight of this species is 600 pounds (272.0 kg). |
| more typically down to about 200 meters, though it has been reported as deep as 1,000 meters | An oceanic species, the oarfish is found living at great depths to 3,280 feet (1,000 m) but more typically to depths of 656 feet (200 m). (note: "reported" is weaker than the source's "found" on purpose, since five-2013 puts the deepest verified record at 463-492 m) |
| It has no visible teeth | Oarfish have no visible teeth. |
| no swim bladder | This species has no swim bladder. |
| instead of scales its skin is coated in silvery guanine | The body is scaleless with the skin covered instead by silvery guanine. |
| strained from the water with specially evolved gill rakers | Oarfish feed on plankton, crustaceans, and squid by straining them from the water column using specially evolved gill rakes located in the mouth. (note: gill "rakes" is the source's spelling of gill rakers) |
| one fish caught off California contained 10,000 krill | One specimen caught off the coast of California contained a large volume (10,000 individuals) of krill (euphausids). |
| It is believed to live alone except when spawning | This species is believed to live solitary lives with the exception of spawning activities. |
| A close relative, the streamer fish, has been reported to give a mild electric shock when handled, though it is unclear whether the giant oarfish can too | A close relative of the oarfish, the streamer fish (Agrostichthys parkeri) has been reported to be electrogenic, producing a mild shock when handled by humans. It is unclear if the oarfish shares this capability. |
| Sharks and other large fish are its main potential predators, on account of its size | Due to its significant size, larger fish including sharks are the primary potential predators of the oarfish. |
| The maximum published weight for the species is 272 kilograms (600 pounds). It is more commonly seen at about 3 meters (10 feet) long. | The maximum reported length of the oarfish is 36 feet (1,100 cm) total length although it is more commonly observed at lengths of approximately 10 feet (300 cm) total length. ... The maximum published weight of this species is 600 pounds (272.0 kg). (note: 3 meters, converted from the source's 10 feet (300 cm)) |
| The giant oarfish keeps its body straight and swims by rippling its long dorsal fin, a style known as amiiform swimming. It has also been seen swimming upright, which is believed to be how it searches for prey. | The oarfish swims by undulating its long dorsal fin while its body remains straight which is knows as an amiiform mode of swimming. It has also been observed swimming in a vertical position in what is believed to be a method that the oarfish searches for prey items. |
| a fish that swims without bending: its body stays straight while a dorsal fin running its whole length undulates | The oarfish swims by undulating its long dorsal fin while its body remains straight ... The dorsal fin originates just above the relatively small eyes, running the entire length of the fish. (note: vibe.reason (task #211); replaces "majestic abyssal stillness", since the species typically lives above 200 m) |
| it has been seen swimming upright | It has also been observed swimming in a vertical position (note: vibe.reason (task #211)) |

## McClain et al. (2015). Sizing ocean giants: patterns of intraspecific size variation in marine megafauna. PeerJ.

https://doi.org/10.7717/peerj.715

| The page says | The source says |
| :--- | :--- |
| a detailed 2012 study found the largest museum specimens were just under 8 meters long, and no evidence that any oarfish grows longer | Roberts (2012) recent thorough description of Regalecus ... The largest specimens preserved in museum collections, of both R. russellii and R. glesne, are just under 8 m total length. I have not been able to find any evidence that Regalecus ever attain lengths greater than this. (note: "any oarfish" is the genus Regalecus, the source's scope) |
| A report of a 15 to 16 meter oarfish stranded on Stronsay Island in the Orkneys in 1808 was based on the rotting carcass of a large basking shark | The report of a 15–16 m (50–60 foot) long Regalecus stranded on Stronsay Island in the Orkneys in 1808 is based upon the rotting carcass of a large basking shark. |
| Records of 10 to 11 meters added an estimated length for the missing tail end | Records of oarfish 10, 10.7, or 11 m total length are based on addition of extrapolated lengths of the posterior part of the body lost at much smaller sizes. (note: "tail end" for "posterior part of the body") |

## Benfield et al. (2013). Five in situ observations of live oarfish Regalecus glesne (Regalecidae) by remotely operated vehicles in the oceanic waters of the northern Gulf of Mexico. Journal of Fish Biology.

https://doi.org/10.1111/jfb.12144

| The page says | The source says |
| :--- | :--- |
| Underwater robots in the Gulf of Mexico spotted it at 463 to 492 meters, the deepest verified record of the species as of 2013 | five observations of apparently healthy oarfish Regalecus glesne by remotely operated vehicles are reported from the northern Gulf of Mexico. ... These observations include the deepest verified record of R. glesne (463-492 m) (note: "underwater robots" for remotely operated vehicles; 2013 is the paper's publication year, dating the record) |

## Albano et al. (2022). Distribution of the Order Lampriformes in the Mediterranean Sea with Notes on Their Biology, Morphology, and Taxonomy.

https://doi.org/10.3390/biology11101534

| The page says | The source says |
| :--- | :--- |
| Researchers suggest that for long, thin fish like oarfish, an upright stance | more elongated species such as the oar-ribbon fishes usually orientate their body vertically (note: the review's scope is the elongate lampriforms, the oar-ribbon fishes among them; the mechanism is claimed separately below) |
| an upright stance may help them spot prey against light filtering down from above while making their own outline harder to see | the maintenance of a vertical position in the water column during predation, which was reported also for some Lampriformes species [ 7 , 8 ]. This feature may help these fish in the visualization of prey against downwelling light, and, at the same time, allow these elongate fish to minimize their appearance (note: "downwelling light" paraphrased as "light filtering down from above"; "may help" kept as the source's hedge, with "Researchers suggest" for its attribution) |

## Orihara et al. (2019). Is Japanese Folklore Concerning Deep‐Sea Fish Appearance a Real Precursor of Earthquakes? Bulletin of the Seismological Society of America.

https://doi.org/10.1785/0120190014

| The page says | The source says |
| :--- | :--- |
| In Japan, folklore says an unusual appearance of a deep-sea fish such as an oarfish warns of a coming earthquake | In Japan, folklore says that uncommon appearances of deep-sea fish are an earthquake precursor. ... fish species generally implicated in earthquakes, such as oarfish and slender ribbonfish, were the focus. |
| a statistical study built a database of newspaper and museum reports of these appearances, compared them against earthquake records, and found almost no link in place or time, calling the belief a superstition | However, a statistical survey has not been conducted on this subject because a database of such information had yet to be compiled. ... The authors constructed a database of reports from newspapers, academic articles, and the marine museum. ... the earthquake occurrence rate after deep-sea fish appearances can be evaluated. ... the spatiotemporal relationship between deep-sea fish appearances and earthquakes was hardly found. Hence, this Japanese folklore is deemed to be a superstition attributed to the illusory correlation between the two events. (note: "almost no link in place or time" for "the spatiotemporal relationship ... was hardly found") |
| Japanese folklore says an unusual appearance of a deep-sea fish such as an oarfish warns of a coming earthquake. A 2019 study built a database of newspaper, academic and museum reports of these appearances and compared them against earthquake records, finding almost no link in place or time between the two. The researchers concluded the belief is a superstition. | In Japan, folklore says that uncommon appearances of deep-sea fish are an earthquake precursor. ... The authors constructed a database of reports from newspapers, academic articles, and the marine museum. ... the earthquake occurrence rate after deep-sea fish appearances can be evaluated. ... the spatiotemporal relationship between deep-sea fish appearances and earthquakes was hardly found. Hence, this Japanese folklore is deemed to be a superstition attributed to the illusory correlation between the two events. (note: 2019 is the paper's publication year (metadata), not text in the abstract itself) |

## Smith-Vaniz (2015). Regalecus glesne. The IUCN Red List of Threatened Species 2015: e.T190378A115316206.

https://doi.org/10.2305/iucn.uk.2015-4.rlts.t190378a21911480.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN Red List category: Least Concern (LC). |

## Lozano-Cobo et al. (2021). Molecular Identification of Plerocercoids of Clistobothrium montaukensis (Cestoda: Phyllobothriidea) Parasitizing the King of Herrings Regalecus glesne. Acta Parasitologica.

https://doi.org/10.1007/s11686-021-00400-9

| The page says | The source says |
| :--- | :--- |
| Few parasites have been recorded in this fish, but scientists once pulled 63 tapeworm larvae from the intestine of an adult giant oarfish stranded in Mexico | there are few records of parasites from either Regalecus species. We report plerocercoid larvae of phyllobothriidean cestodes parasitizing an adult R. glesne stranded in Bahía de La Paz, Baja California Sur, Mexico ... Sixty-three plerocercoids were obtained from the intestine of R. glesne (note: "63" appears as "Sixty-three" in the source; plerocercoids of cestodes are tapeworm larvae) |