What the sources say
Gulper Eel (Pelican Eel)Eurypharynx pelecanoides
Every figure, record and mechanism on the Gulper Eel (Pelican Eel) profile was written from a source, and this is the working table behind it: 47 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.
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Source
01
FishBase
Eurypharynx pelecanoides. FishBase.
- The page saysa glowing tail tip
- The source says
Tail attenuated and ending in an expanded, luminous caudal organ.
- The page saysTropical and temperate oceans worldwide
- The source says
Circumglobal: In tropical to temperate waters.
- The page saysfrom about 500 to 7,625 meters deep and usually around 1,200 to 1,400 meters
- The source says
depth range 500 - 7625 m (Ref. 58426 ), usually 1200 - 1400 m (Ref. 559 )
- The page saysMainly crustaceans, plus fish, squid and their relatives, and other invertebrates
- The source says
Adults feed mainly on crustaceans, but also take fishes, cephalopods, and other invertebrates
Note: 'Squid and their relatives' renders 'cephalopods' for a young reader. - The page sayshas a mouth greatly enlarged by jaws that extend backward
- The source says
Mouth greatly enlarged by a backward extension of jaws, gape comprising half or more of preanal length; buccal cavity greatly distensible.
- The page saysIts gape is half or more of the length from its snout to its vent
- The source says
Mouth greatly enlarged by a backward extension of jaws, gape comprising half or more of preanal length; buccal cavity greatly distensible.
Note: FishBase's 'preanal length' is snout to anus (vent); 'its rear opening' defines the vent for a young reader. - The page saysthe inside of its mouth can stretch enormously
- The source says
Mouth greatly enlarged by a backward extension of jaws, gape comprising half or more of preanal length; buccal cavity greatly distensible.
Note: 'Buccal cavity greatly distensible' rendered for a young reader. - The page saysGulper eels live in tropical and temperate oceans worldwide
- The source says
Circumglobal: In tropical to temperate waters.
- The page saysbetween about 500 and 7,625 meters down, though they usually stay around 1,200 to 1,400 meters
- The source says
depth range 500 - 7625 m (Ref. 58426 ), usually 1200 - 1400 m (Ref. 559 )
- The page saysIn the eastern Pacific they range from northern California to Peru
- The source says
Eastern Pacific: ranges from northern California to Peru.
- The page saysInstead of pores, the gulper eel's lateral line has groups of raised tubes
- The source says
lateral line without pores, instead with groups of elevated tubules
- The page saysIts eggs hatch into drifting larvae called leptocephali
- The source says
Oviparous, planktonic eggs hatch into planktonic leptocephalus larvae
- The page saysIt can grow to 1 meter long, though 55 centimeters is a more common length
- The source says
Max length : 100.0 cm TL male/unsexed; (Ref. 27000 ); common length : 55.0 cm NG male/unsexed; (Ref. 5755 )
Note: 100 cm is 1 meter. - The page saysit is of no interest to fisheries
- The source says
Human uses Fisheries: of no interest
- The page saysThey have been recorded from about 500 to 7,625 meters down, though they usually stay around 1,200 to 1,400 meters
- The source says
depth range 500 - 7625 m (Ref. 58426 ), usually 1200 - 1400 m (Ref. 559 )
- The page saysGulper eels live across the world's tropical and temperate oceans, and in the eastern Pacific they range from northern California to Peru
- The source says
Circumglobal: In tropical to temperate waters. Eastern Pacific: ranges from northern California to Peru.
- The page saysIts tapering tail ends in an expanded organ that gives off light
- The source says
Tail attenuated and ending in an expanded, luminous caudal organ.
- The page saysThe IUCN assessed it as Least Concern in 2012
- The source says
Least Concern (LC) ; Date assessed: 24 May 2012
Note: FishBase's IUCN field (Red List version 2025-2) shows the 2012 assessment is still the current one. - The page saysit is of no interest to fisheries
- The source says
Human uses Fisheries: of no interest
- The page saysdangerLevel: Low
- The source says
Threat to humans Harmless
Source
02
Nielsen, Bertelsen & Jespersen 1989
Nielsen, Bertelsen & Jespersen (1989). The Biology of Eurypharynx pelecanoides (Pisces, Eurypharyngidae). Acta Zoologica.
- The page saysA huge gape
- The source says
The huge gape is unsuitable for suction feeding.
- The page saysprobably engulfed by a forward thrust of the head
- The source says
It is proposed that prey engulfing is accomplished by a forward thrust of the head by which the produced water pressure will expand the buccal cavity to a volume several times that of the fish itself.
Note: 'Probably' carries the source's 'It is proposed'. - The page saysresearchers propose can expand to several times the eel's own body volume
- The source says
It is proposed that prey engulfing is accomplished by a forward thrust of the head by which the produced water pressure will expand the buccal cavity to a volume several times that of the fish itself.
- The page saysA 1989 study of 760 Atlantic specimens
- The source says
This paper is based on 760 Atlantic specimens of pelican eels caught from off Iceland to 48°S in depths between 2750 and c. 500 m.
Note: 1989 is the reference's publication year. - The page saysjudged that huge gape unsuitable for sucking prey in
- The source says
The huge gape is unsuitable for suction feeding.
- The page saysthe researchers proposed, the eel thrusts its head forward, and the water pressure this creates expands its mouth to several times the volume of the eel itself
- The source says
It is proposed that prey engulfing is accomplished by a forward thrust of the head by which the produced water pressure will expand the buccal cavity to a volume several times that of the fish itself.
- The page saysIn the 1989 study, stomachs from 120 eels held a varied diet led by crustaceans, fish and squid
- The source says
Stomach contents from 120 specimens show a varied diet dominated by crustaceans, fish and squid.
Note: 1989 is the reference's publication year. - The page saysoften Sargasso weed too, which the researchers took as a sign that the eel does not pick and choose what it swallows
- The source says
The frequent occurrence of Sargasso weed consumed by Eurypharynx indicates a lack of prey-item discrimination.
- The page saysIts forward-facing eyes appear to give it depth vision for locating prey, possibly helped by its well developed lateral line
- The source says
The forward directed eyes appear to enable stereoscopic prey localization, possibly aided by the well developed lateral line.
Note: 'Depth vision for locating prey' renders 'stereoscopic prey localization'. The lateral line definition is general knowledge. - The page saysIn the 1989 study, ripening fish, males especially, changed in some body features, a sign of that single breeding
- The source says
When ripening, males especially show morphological changes in some characters, indicating that the pelican eel breeds only once
Note: 1989 is the reference's publication year. - The page saysBreeding only once seems to be the rule among eels in general
- The source says
a condition which seems to be the rule among eels
- The page saysNot by sucking it in
- The source says
The huge gape is unsuitable for suction feeding.
- The page saysa 1989 study of 760 Atlantic specimens judged the huge gape unsuitable for that
- The source says
This paper is based on 760 Atlantic specimens of pelican eels caught from off Iceland to 48°S in depths between 2750 and c. 500 m.
Note: 1989 is the reference's publication year; the verdict is the abstract's 'The huge gape is unsuitable for suction feeding.' - The page saysThe researchers proposed that the eel thrusts its head forward instead, and the water pressure this creates expands its mouth to several times the volume of the eel itself
- The source says
It is proposed that prey engulfing is accomplished by a forward thrust of the head by which the produced water pressure will expand the buccal cavity to a volume several times that of the fish itself.
Source
03
Kim et al. 2019
Kim et al. (2019). Bioinspired dual-morphing stretchable origami. Science Robotics.
- The page saysa mouth that first unfolds and then inflates
- The source says
which first unfolds and then inflates its mouth to maximize the probability of engulfing the prey
- The page saysA mouth that first unfolds and then inflates
- The source says
which first unfolds and then inflates its mouth to maximize the probability of engulfing the prey
- The page saysRobot designers have copied that mouth
- The source says
we built an artificial creature mimicking a pelican eel and reproduced biomimetic dual-morphing behavior
- The page saysTheir 2019 paper describes it changing shape in two steps: it first unfolds and then inflates, to give the eel the best chance of engulfing its prey
- The source says
the "dual-mode" morphing of Eurypharynx pelecanoides (commonly known as the pelican eel), which first unfolds and then inflates its mouth to maximize the probability of engulfing the prey
Note: 2019 is the reference's publication year (Science Robotics). - The page saysTheir design uses stretchable origami units that imitate the pelican eel's stretchable, foldable frames
- The source says
a set of entirely stretchable origami units that imitate the morphing principle of the pelican eel's stretchable and foldable frames
- The page saysthe team built an artificial pelican eel that reproduced the same two-step move
- The source says
we built an artificial creature mimicking a pelican eel and reproduced biomimetic dual-morphing behavior
- The page saysa mouth that first unfolds, then inflates to engulf its prey
- The source says
which first unfolds and then inflates its mouth to maximize the probability of engulfing the prey
Source
04
Poulsen et al. 2018
Poulsen et al. (2018). Resolving deep-sea pelagic saccopharyngiform eel mysteries: Identification of Neocyema and Monognathidae leptocephali and establishment of a new fish family "Neocyematidae" based on larvae, adults and mitogenomic gene orders. PLOS ONE.
- The page saysOne Shot Only
- The source says
All of the saccopharyngiforms are one-time spawners
- The page saysGulper eels and the related deep-sea eels in their group all spawn just once in their lives
- The source says
All of the saccopharyngiforms are one-time spawners
- The page saysMost vertebrates arrange the genes in their mitochondria, the energy-producing parts of cells, in the same order
- The source says
The vast majority of vertebrates show a particular mitochondrial gene order
Note: The mitochondria definition is general knowledge. - The page saysa 2018 study found that the gulper eel's family and four related deep-sea eel families each have an order of their own
- The source says
all five families show unique gene orders
Note: The five families are Cyematidae, Eurypharyngidae, Monognathidae, Saccopharyngidae and the new Neocyematidae; 2018 is the reference's year. - The page saysResearchers conclude that the species spawns in the Sargasso Sea, where its larvae are often caught, small ones included
- The source says
It is frequently collected as leptocephali in the Sargasso Sea where it spawns based on the presence of small larvae.
Source
05
Iwamoto 2015
Iwamoto (2015). Eurypharynx pelecanoides. The IUCN Red List of Threatened Species 2015: e.T18227119A42691734.
- The page saysThe IUCN rates it Least Concern
- The source says
IUCN Red List category: Least Concern (LC).
How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.