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What the sources say

FangtoothAnoplogaster cornuta

Every figure, record and mechanism on the Fangtooth profile was written from a source, and this is the working table behind it: 50 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

Kierdorf et al. 2022

Kierdorf et al. (2022). Dental structure and tooth attachment modes in the common fangtooth Anoplogaster cornuta (Valenciennes, 1833) (Actinopterygii; Trachichthyiformes; Anoplogastridae). PLOS ONE.

The page saysreported to have the largest teeth of any marine fish for its head size
The source saysRelative to its head size, which accounts for about one-third of the maximum adult body length of about 16 to 17cm, Anoplogaster cornuta possesses the largest teeth of any marine fishNote: Kierdorf et al. attribute this to their ref [2], which is the ADW account (ADW puts it 'Relative to body size, they have the largest teeth of any marine species'), hence 'reported'
The page saysfangs so long an adult cannot fully close its mouth
The source saysThe long anterior fang teeth of the oral jaws prevent adult individuals from completely closing their mouth
The page saysFangs so long that the lower pair slide into pockets in the roof of its mouth
The source sayswith the fangs of the lower jaw sliding into pockets in the roof of the mouth when it is partially closed
The page saysreportedly the largest teeth of any marine fish for its head size
The source saysRelative to its head size, which accounts for about one-third of the maximum adult body length of about 16 to 17cm, Anoplogaster cornuta possesses the largest teeth of any marine fishNote: attributed by the authors to ADW, their ref [2]
The page saysAn adult fangtooth's head takes up about a third of its maximum body length of about 16 to 17 centimetres
The source saysRelative to its head size, which accounts for about one-third of the maximum adult body length of about 16 to 17cm
The page saysIts long front fangs stop an adult from closing its mouth completely: when the jaws are partly shut, the lower fangs slide into pockets in the roof of the mouth
The source saysThe long anterior fang teeth of the oral jaws prevent adult individuals from completely closing their mouth, with the fangs of the lower jaw sliding into pockets in the roof of the mouth when it is partially closed
The page saysA 2022 microscope study of two adults caught in the North Atlantic
The source saysTwo adult specimens of Anoplogaster cornuta (total length of 12.0 and 13.5 cm, respectively) were caught in 2002 at depths between 680 and 708 meters during an expedition (M244) to the Irmiger and Greenland Sea (North Atlantic Ocean)Note: 2022 is the publication year; microscopy from 'using light- and scanning-electron microscopic techniques'
The page saysfound every tooth made solely of orthodentin
The source saysAll teeth were monocuspid, composed solely of orthodentin, and lacked a covering enameloid cap
The page saysthe jaw teeth fused solid to the bone
The source saysThe oral jaw teeth were transparent, non-depressible and firmly ankylosed to their respective dentigerous bone
The page saysIt found no sign that the big jaw teeth had been replaced
The source saysNo evidence for replacement of the large oral jaw teeth was found in the analyzed adult specimens
The page saysThe teeth in the throat, by contrast, showed signs of replacement: empty sockets and small new teeth
The source saysIn contrast to the oral jaw teeth, the pharyngeal teeth of Anoplogaster cornuta are replaced as is indicated by the presence of empty tooth loci and small, newly established teeth
The page saysRelative to the size of its head, the common fangtooth is reported to have the largest teeth of any fish in the sea
The source saysRelative to its head size, which accounts for about one-third of the maximum adult body length of about 16 to 17cm, Anoplogaster cornuta possesses the largest teeth of any marine fishNote: attributed by the authors to ADW, their ref [2], hence 'reported'
The page saysThe genus holds two species, the common fangtooth (Anoplogaster cornuta) and the shorthorn fangtooth (Anoplogaster brachycera)
The source saysThe two species within the genus are the common or longhorn fangtooth (or sabretooth) (Anoplogaster cornuta) and the shorthorn fangtooth (or sabretooth) (Anoplogaster brachycera)
The page saysTwo Species, and a Case of Mistaken Identity
The source saysThe two species within the genus are the common or longhorn fangtooth (or sabretooth) (Anoplogaster cornuta) and the shorthorn fangtooth (or sabretooth) (Anoplogaster brachycera)Note: 'mistaken identity' is the juveniles-as-separate-species history, claimed below from ADW
The page saysYoung common fangtooths carry long spines on the head and gill cover that shorthorns lack
The source saysJuveniles of the former species possess long temporal and preopercular spines that are missing in the latter
The page saysThe lower jaw's fangs do not start growing until a young fish reaches about 2 centimetres long, the upper fangs wait until 5.3 centimetres, and only around 8 centimetres does a fangtooth begin to look like the adult it will become
The source saysThe large anterior fang-like teeth start to develop in the lower jaw when the animals reach about 2 cm body length, and in the upper jaw at about 5.3 cm body length, and juveniles begin to resemble adults when attaining a body length of about 8 cmNote: 'until' and 'only' paraphrase 'start to develop ... when the animals reach'
The page saysAdults feed mainly on fish and shrimp, typically swallowed whole, and prey can reach a third of their own body size
The source saysAdult individuals mainly feed on fish and shrimps that are typically swallowed whole. Prey size of adults can reach one-third of their body size
The page saysIn the two adults a 2022 study examined, fourteen: three on each side of the upper jaw and four on each side of the lower
The source saysFourteen teeth were present in the oral jaws, with three teeth each on the left and right premaxilla and four teeth each on the left and right dentary
The page sayswith the front tooth on each bone much larger than the rest
The source saysThe anteriormost premaxillary and dentary teeth were considerably larger than the more posteriorly located ones
The page saysEach is fused to the bone and cannot fold back
The source saysThe oral jaw teeth were transparent, non-depressible and firmly ankylosed to their respective dentigerous bone
The page saysNumerous small teeth on the gill arches presumably help hold on to small prey in a habitat where food is sparse
The source saysa firm ankylosis was observed in numerous small teeth located on the branchial arches. The function of these teeth is presumably to increase the tightness of the pharyngeal basket and thereby the retention of small prey items in a species living in a habitat with only sparse food supply
The page saysA fangtooth's fangs are so long that an adult cannot fully close its mouth: when the jaws partly shut, the lower pair slide into pockets in the roof
The source saysThe long anterior fang teeth of the oral jaws prevent adult individuals from completely closing their mouth, with the fangs of the lower jaw sliding into pockets in the roof of the mouth when it is partially closed

Source
02

Portner et al. 2023

Portner et al. (2023). Harnessing a mesopelagic predator as a biological sampler reveals taxonomic and vertical resource partitioning among three poorly known deep-sea fishes. Scientific Reports.

The page saysYoung A. cornuta start out silvery gray
The source saysThis size correlates with an ontogenetic change in coloration from the silvery gray of juveniles to the black or dark brown of adults
The page saysA 2023 study examined 91 juvenile fangtooth, weighing 0.6 to 22 grams, recovered from the stomachs of longnose lancetfish
The source saysWe examined specimens sampled from the stomachs of longnose lancetfish, Alepisaurus ferox, to describe the diets and foraging behaviors of three common, but poorly known deep-sea fishes: the hammerjaw (Omosudis lowii, n = 79, 0.3-92 g), juvenile common fangtooth (Anoplogaster cornuta, n = 91, 0.6-22 g)Note: 2023 is the publication year
The page sayscaught on Hawaii-based longlines in the central North Pacific
The source saysLancetfish stomachs were collected by federal fisheries observers in the Hawaiʻi-based longline fisheryNote: central North Pacific (CNP) is the study area named throughout the paper
The page saysThey specialized on tiny crustaceans called hyperiid amphipods
The source saysJuvenile Anoplogaster specialize on hyperiid amphipods
The page saysone family, Phrosinidae, turned up in 86 percent of stomachs
The source saysexhibited a high degree of specialization on Phrosinidae (65% M ¯ ps , 86% FO )Note: FO is 'the percent frequency of occurrence per predator'; the 65% figure the writer used is %M̄ps, mass computed only over stomachs that held Phrosinidae, so it was cut
The page saysTheir estimated mean foraging depth, about 200 metres, was the shallowest of the three species studied
The source saysAnoplogaster cornuta had the shallowest mean estimated foraging depth (GAM, intercept = 202.38 m, 95% CI [135.37, 269.39], p < 0.001)Note: 202.38 m rounded; the three species are A. cornuta, Alepisaurus ferox and Omosudis lowii
The page saysYoung fangtooth also end up in the stomachs of longnose lancetfish
The source saysWe examined specimens sampled from the stomachs of longnose lancetfish, Alepisaurus ferox, to describe the diets and foraging behaviors of three common, but poorly known deep-sea fishes

Source
03

Animal Diversity Web, University of Michigan

Anoplogaster cornuta (common sabertooth). Animal Diversity Web, University of Michigan.

The page saysBathypelagic and mesopelagic open ocean worldwide, mostly 500 to 2,000 meters down, to a maximum of about 5,000 meters
The source saysis an exclusively marine species and exists from bathypelagic to mesopalagic depths ranging from 2 m to 4992 m below sea level; however, it is most common between 500 m and 2000 m. Adults are commonly captured at depths ranging from 75 to 5000 m
The page saysFish and shrimp as adults, tiny drifting crustaceans as juveniles
The source saysJuveniles feed on crustaceans, while adults feed primarily on fish and shrimpNote: 'drifting' (epipelagic hyperiid amphipods) is from portner-2023: 'Many stomachs were full of epipelagic crustaceans'
The page sayslarge-eyed and spiny-headed
The source saysJuveniles have a long cephalic and preopercular spine. Their eyes are large
The page saysadults turn small-eyed, spineless and black or dark brown
The source saysadults do not have cephalic or preopercular spines. Their eyes are comparatively smallNote: colour from portner-2023: 'to the black or dark brown of adults'
The page saysJuveniles and adults look so different that in the 1800s they were believed to be separate species
The source saysAdult and juvenile fangtooths are so morphologically dissimilar that they were believed to be separate species in the 1800s
The page saysWith a full mouth, a fangtooth cannot pump water over its gills efficiently
The source saysWhen fangtooth’s have a full mouth, they are prohibited from efficiently pumping water over the gills for respiration
The page saysInstead it bulges out the opercula, the bony gill covers, exposing the gill arches
The source saysits opercula are greatly distended, which visibly exposes all of the gill arches
The page saysfans water over them from behind with its pectoral fins until the prey has been swallowed
The source saysit subsequently uses its pectoral fins to fan seawater over the gills from behindNote: 'until the prey has been swallowed' from 'This species maintains opercular distension while handling its prey, ceasing only after prey has been swallowed'
The page saysAnoplogaster cornuta lives worldwide in tropical, temperate and subarctic seas
The source saysfound worldwide in tropical to temperate and subartctic seas
The page saysmost often between 500 and 2,000 metres down, though adults have been caught as deep as 5,000 metres
The source saysit is most common between 500 m and 2000 m. Adults are commonly captured at depths ranging from 75 to 5000 m
The page saysIt is stenothermic, adapted to a narrow band of 4 to 6°C
The source saysAnoplogaster cornuta is stenothermic and is adapted to temperatures between 4°C and 6ºC
The page saysIts dark brown to black colouring likely lowers the risk of being eaten where little or no sunlight reaches
The source saysTheir dark brown to black color likely reduces predation risk at depths with little to no sunlight penetration
The page saysFangtooth are not bioluminescent, so they make no light of their own. Adults can live deeper than sunlight reaches
The source saysSunlight does not penetrate to bathypelagic depths at which adults may be found, and they are not bioluminescent
The page saystheir eyes are comparatively small
The source saysTheir eyes are comparatively small
The page saysat those depths the eyes are unlikely to be of much use
The source saysThus, it is unlikely that their eyes are of much necessity at greater depths
The page saysThey are thought to spawn from June to August
The source saysFangtooths are thought to breed from June to August
The page sayslaying eggs that hatch into planktonic (drifting) larvae, and the parents give no care
The source saysFangtooths are oviparous and have planktonic larvae. There is no parental care
The page saysLittle else is known of how the species reproduces
The source saysLittle else is known of reproduction in this species
The page saysTuna, including albacore, and marlin are listed as major predators
The source saysMajor predators of Anoplogaster cornuta include tuna (e.g., albacore), and marlin
The page saysdangerLevel: Low
The source saysThere are no known adverse effects of Anoplogaster cornuta on humans.

Source
04

Iwamoto 2015

Iwamoto (2015). Anoplogaster cornuta. The IUCN Red List of Threatened Species 2015: e.T18123960A21910070.

The page saysThe IUCN lists the species as Least Concern
The source saysIUCN Red List category: Least Concern (LC)Note: category read through GBIF's copy of the Red List, since iucnredlist.org refuses scripts

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.