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What the sources say

Ocean Sunfish (Mola Mola)Mola mola

Every figure, record and mechanism on the Ocean Sunfish (Mola Mola) profile was written from a source, and this is the working table behind it: 73 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

Animal Diversity Web, University of Michigan

Mola mola (Ocean Sunfish). Animal Diversity Web, University of Michigan.

The page saysLarge sharks often prey on sunfish
The source saysOcean sunfish are often preyed upon by large sharks and California sea lionsNote: ADW is dated 2011; its sea-lion half is narrowed by FishBase's current page (next claim)
The page sayscleaner fish such as wrasses and angelfish pick off its parasites when it occasionally visits kelp beds and reefs
The source saysoccasionally venture into kelp beds and deep coral reefs in order to be cleaned of parasites by fishes such as wrasses (Labroides dimidiatus and Thalasoma lunare) and Emperor Angelfish
The page saysThe clavus is the rudder-like structure at the rear of the fish
The source saysthey instead have a clavus, which is a truncated tail, used more like a rudder than for propulsion

Source
02

FishBase

Mola mola (Linnaeus, 1758), Ocean sunfish. FishBase.

The page saysUp to 1.3 tonnes
The source saysmax. published weight: 1.3 tNote: 1.3 t worded as 1.3 tonnes
The page saysthen floats flat at the surface between dives
The source saysIndividuals often drift at the surface while lying on its side
The page saysTemperate and tropical oceans worldwide
The source saysCircumglobal: tropical and temperate zones of all oceans.Note: backs stats.habitat
The page saysA body with no tail fin, steered by a stiff clavus rudder
The source saysThe caudal fin is replaced by a rudder-like structure calledNote: backs stats.superpower
The page saysThe ocean sunfish (Mola mola) can grow past 3 meters long and weigh up to 1.3 tonnes
The source saysMax length : 333 cm TL male/unsexed; ... max. published weight: 1.3 tNote: 333 cm TL is worded as 'past 3 meters'; a maximum, so 'can grow'
The page saysCalifornia sea lions go after the juveniles in Monterey Bay
The source saysJuveniles are victims of California sea lions in Monterey BayNote: 'go after' is the phrasal verb for hunting (the source's 'are victims of'), not a sequence; FishBase is current and narrows ADW 2011's general sea-lion line
The page saysA Mola mola can grow past 3 meters long and weigh up to 1.3 tonnes
The source saysMax length : 333 cm TL male/unsexed; ... max. published weight: 1.3 tNote: 333 cm TL is worded as 'past 3 meters'
The page saysIts name comes from the Latin for millstone
The source saysEtymology: Mola: Latin, mola, -ae = stone mill; because of the shape of this fish
The page saysOne 1.5-meter female was found carrying about 300 million eggs, the largest clutch estimate for the species
The source says300 million eggs found in a 1.5 m long female ... This is the largest clutch estimate for this speciesNote: was 'A female can carry roughly 300 million eggs in one spawning': the figure is one 1.5 m female, and FishBase calls the species a multiple spawner, so not one spawning

Source
03

Oceana

Ocean Sunfish. Oceana.

The page saysthen floats flat at the surface between dives
The source saysBecause they must sometimes dive into deep, cold waters to catch their prey, these fish will warm up by basking on their side at the waterNote: the 'between dives' half
The page saysjuveniles can pack on up to 0.82 kilograms a day
The source saysthey can grow up to 0.82 kilograms (1.8 pounds) every single day
The page saysconsistent with basking between dives to recover warmth
The source saysthese fish will warm up by basking on their side at the waterNote: backs 'basking'
The page saysThey are most likely warming back up after cold, deep dives
The source saysBecause they must sometimes dive into deep, cold waters to catch their prey, these fish will warm up by basking on their side at the waterNote: hedged 'most likely' because Nakamura et al. 2015 only 'suggest' it and the Australian Museum quotes Potter and Howell 2010 finding no evidence for it; reviewer cut 'not sunbathing for fun'

Source
04

Australian Museum

Ocean Sunfish, Mola mola. Australian Museum.

The page sayswith no tail fin
The source saysThese interesting fish are completely without a caudal finNote: reviewer: replaces 'finless'; sunfish have dorsal, anal and pectoral fins, only the caudal fin is missing
The page saystagged fish spent most of their time in the top 200 meters
The source saysover 80% of time in the top 200 mNote: backs stats.habitat; kept at the tagging study's scope; the Australian Museum page quotes this figure from Potter and Howell 2010
The page saysand one dived to 844 meters
The source saysThe maximum depth recorded by any fish was 844 m.Note: backs stats.habitat; the page quotes this from Potter and Howell 2010. Reviewer cut 'to feed', which no source ties to that dive
The page saysJellyfish, comb jellies and siphonophores
The source saysOcean Sunfish feed on jellyfish, salps, ctenophoresNote: backs stats.diet; 'comb jellies' is the common name for ctenophores; siphonophores backed by nakamura-2015 below. Reviewer dropped 'as adults': no source gives the adult diet as such
The page saysthe clavus, the sunfish's rudder-like rear end, has a wavy, frilled edge in Mola mola and a rounded one with no indent in M. alexandrini
The source saysMola mola can be identified from its wavy (frilly) clavus edge, 11-14 clavus fin rays ... (the clavus is round without an indent in Mola alexandrini and rounded with an indent in Mola tecta)Note: reviewer: 'smooth' replaced by the source's own 'without an indent'
The page saysSunfish have no tail fin
The source saysThese interesting fish are completely without a caudal fin
The page saysone tracking study logged a dive to 844 meters
The source saysThe maximum depth recorded by any fish was 844 m.Note: the page quotes this from Potter and Howell 2010
The page saysa nod to its rounded shape
The source saysthe name Mola comes from the Latin word for millstone and refers to the rounded shape of the fishNote: was 'round, flattened shape'; neither source says flattened
The page saysits family, Molidae, includes the largest bony fish in the world
The source saysSunfish are from the family Molidae and are the largest bony fish in the world.

Source
05

Jing et al. 2015

Jing et al. (2015). Mola mola. The IUCN Red List of Threatened Species 2015: e.T190422A1951231.

The page saysVulnerable
The source saysIUCN Red List category: Vulnerable (VU).Note: backs stats.conservationStatus; FishBase lists the same category under Red List version 2025-2 (assessed 07 June 2011), so it is current

Source
06

Sawai & Nyegaard 2022

Sawai & Nyegaard (2022). A review of giants: Examining the species identities of the world's heaviest extant bony fishes (ocean sunfishes, family Molidae). Journal of Fish Biology.

The page saysFor a long time it also carried a bigger title: the world's heaviest bony fish, at around 2,300 kilograms
The source saysThe world's heaviest extant bony fish has long been considered the ocean sunfish Mola mola (family Molidae). However, recent taxonomic research suggests the world record specimen (2300 kg) was actually a misidentified giant sunfish M. alexandrini.Note: 'for a long time' for the source's 'long been considered' (was 'for decades')
The page saysA 2022 review of giant-sunfish records found that the specimen behind that number wasn't Mola mola
The source sayswe confirm that the world's heaviest extant bony fish specimen actually weighed was a female M. alexandrini (2300 kg, 272 cm total length) captured from Kamogawa, Chiba Prefecture, Japan, on August 16, 1996.Note: 2022 is the paper's own publication year; 'wasn't Mola mola' reflects the paper's own confirmed finding, not the earlier hedged 'suggests' sentence
The page saysIt was a giant sunfish, Mola alexandrini, a separate species caught off Japan in 1996
The source saysthe world's heaviest extant bony fish specimen actually weighed was a female M. alexandrini (2300 kg, 272 cm total length) captured from Kamogawa, Chiba Prefecture, Japan, on August 16, 1996
The page saysthe same review concluded M. alexandrini is the only living bony fish researchers could confirm above 2,000 kilograms
The source sayswe conclude that M. alexandrini is the only extant bony fish species we could confirm that exceeds 2000 kgNote: 'living' restores the source's 'extant'; 'above' is the source's 'exceeds'
The page saysSo Mola mola is enormous, just not the outright record-holder its old reputation claims
The source sayswe confirm that the world's heaviest extant bony fish specimen actually weighed was a female M. alexandriniNote: follows from the confirmed record specimen being M. alexandrini; 'enormous' rests on the 1.3 t above
The page saysNo, though it was long thought to be
The source saysThe world's heaviest extant bony fish has long been considered the ocean sunfish Mola molaNote: was 'Not anymore', which implied the fish once held the record; the record fish was never Mola mola
The page saysThe title rested on a specimen weighed at about 2,300 kilograms
The source saysthe world record specimen (2300 kg) was actually a misidentified giant sunfish M. alexandrini
The page saysa 2022 review of giant-sunfish records found that fish had been misidentified
The source sayswe confirm that the world's heaviest extant bony fish specimen actually weighed was a female M. alexandrini (2300 kg, 272 cm total length) captured from Kamogawa, Chiba Prefecture, Japan, on August 16, 1996.Note: 2022 is the paper's own publication year; reflects the paper's own confirmed finding, not the earlier hedged 'suggests' sentence
The page saysit was actually a giant sunfish, Mola alexandrini, a separate species caught off Japan in 1996
The source sayscaptured from Kamogawa, Chiba Prefecture, Japan, on August 16, 1996
The page saysThe review concluded Mola alexandrini is the only living bony fish researchers could confirm above 2,000 kilograms
The source sayswe conclude that M. alexandrini is the only extant bony fish species we could confirm that exceeds 2000 kgNote: 'living' restores the source's 'extant'; 'above' is the source's 'exceeds'
The page saysso the true ocean sunfish is a very big fish, just not the outright record-holder its old reputation claims
The source sayswe confirm that the world's heaviest extant bony fish specimen actually weighed was a female M. alexandriniNote: follows from the confirmed record specimen being M. alexandrini

Source
07

Watanabe & Sato 2008

Watanabe & Sato (2008). Functional Dorsoventral Symmetry in Relation to Lift-Based Swimming in the Ocean Sunfish Mola mola. PLoS ONE.

The page sayscartilage-and-jelly fish
The source saysthey are neutrally buoyant independent of depth because of their subcutaneous gelatinous tissueNote: the 'jelly' half
The page saysdriven by synchronized, penguin-style dorsal and anal fin strokes
The source saysthey stroked their dorsal and anal fins synchronously ... to generate a lift-based thrust, as penguins do using two symmetrical flippersNote: backs stats.superpower
The page saysThe dorsal and anal fins do the work instead, beating side to side in sync
The source saysLateral acceleration oscillated regularly, showing that the fish stroked their dorsal and anal fins from side-to-side
The page saysthe way a penguin flaps both flippers together, to generate lift-based thrust rather than a drag-based push
The source saysdemonstrating that the thrust was lift-based rather than drag-based. This pattern of acceleration was previously reported in penguins [7] , which flap both flippers synchronously, indicating that ocean sunfish oscillate the dorsal and anal fins synchronously
The page saysTagged sunfish cruised at 0.4 to 0.7 meters per second, in the same range as salmon and marlin
The source sayssunfish indeed swam continuously with frequent vertical movements at speeds of 0.4-0.7 m s-1, which is similar to the records of other large fishes such as salmons, marlins, and pelagic sharksNote: kept at the tagged fish's scope; was 'That gets a sunfish cruising', which made the fin stroke the cause of the measured speed
The page saysThis is not the limp drifter its reputation suggests
The source saysContrary to the common view that ocean sunfish are planktonic fish at the mercy of oceanic currents, the sunfish tagged in this study swam actively
The page saysa thick gelatinous layer under the skin made up 44 percent of the weight of one 247-kilogram fish
The source saysThe proportion of the mass of the gelatinous tissue to body mass significantly increased with body size ... to 44% for a 247-kg individualNote: was 'can make up nearly half a large fish's weight', from one 247-kg individual
The page sayskeeping the whole fish neutrally buoyant without a swim bladder
The source sayssunfish lack a swimbladder, we found that they are neutrally buoyant independent of depth because of their subcutaneous gelatinous tissue that has low density and is incompressible
The page saysActual propulsion comes from those same dorsal and anal fins beating side to side in unison, generating lift-based thrust the way a penguin's two flippers do
The source saysthey stroked their dorsal and anal fins synchronously ... to generate a lift-based thrust, as penguins do using two symmetrical flippers
The page saysfor a fish with no tail fin that swims by stroking its dorsal and anal fins side to side in sync
The source saysthey stroked their dorsal and anal fins synchronously ... to generate a lift-based thrust, as penguins do using two symmetrical flippersNote: task #812, vibe.reason; 'no tail fin' is claimed elsewhere from australian-museum-mola-mola

Source
08

Sims et al. 2009

Sims et al. (2009). Long-Term GPS Tracking of Ocean Sunfish Mola mola Offers a New Direction in Fish Monitoring. PLoS ONE.

The page saysone GPS-tagged fish covered an estimated 1,819 kilometers over 92 days
The source saysSunfish 3, the largest of the fish tagged (1.0 m TL), was tracked for 92 days ... This fish covered an estimated distance of 1,819 km

Source
09

Nakamura, Goto & Sato 2015

Nakamura, Goto & Sato (2015). Ocean sunfish rewarm at the surface after deep excursions to forage for siphonophores. Journal of Animal Ecology.

The page saysIt dives for siphonophores
The source saysSiphonophores were the most abundant prey items captured by ocean sunfish
The page saysJellyfish, comb jellies and siphonophores
The source saysSiphonophores were the most abundant prey items captured by ocean sunfishNote: backs the 'siphonophores' part of stats.diet
The page saysCamera tags have caught sunfish hunting siphonophores on repeated daytime dives to roughly 100 to 200 meters, in water colder than 12°C
The source saysSiphonophores were the most abundant prey items captured by ocean sunfish and were typically located at a depth of 50-200 m where the water temperature was <12 °C ... foraged mainly at 100-200 m depths during the dayNote: 'colder than 12°C' is worded from the source's '<12 °C'; was 'caught adults', but the abstract gives no size or age for the tagged fish
The page saysDeep dives cost heat
The source saysThe body temperatures decreased during deep excursionsNote: was 'Every dive costs heat'; the source says deep excursions
The page saysA sunfish's body temperature drops on the way down
The source saysThe body temperatures decreased during deep excursions
The page saysresearchers found the rate of heat exchange runs 3 to 7 times greater at the surface than while cooling
The source saysthe whole-body heat-transfer coefficient between sunfish and the surrounding water during warming was 3-7 times greater than that during coolingNote: 'rate of heat exchange' is plain-English for the source's 'whole-body heat-transfer coefficient'; warming happens 'during subsequent surfacing periods'
The page saysconsistent with basking between dives to recover warmth
The source saysthese results suggest that the main function of surfacing is the recovery of body temperatureNote: 'consistent with' preserves the source's own hedge ('these results suggest'); reviewer cut 'rather than relax'
The page sayssunfish diving repeatedly to about 100 to 200 meters, into water colder than 12°C, to hunt siphonophores
The source saysSiphonophores were the most abundant prey items captured by ocean sunfish and were typically located at a depth of 50-200 m where the water temperature was <12 °C ... foraged mainly at 100-200 m depths during the dayNote: 'colder than 12°C' is worded from the source's '<12 °C'
The page saysEach deep dive drops their body temperature
The source saysThe body temperatures decreased during deep excursions
The page saysresearchers found the rate of heat exchange runs 3 to 7 times greater once the fish is back at the surface than it did while cooling
The source saysthe whole-body heat-transfer coefficient between sunfish and the surrounding water during warming was 3-7 times greater than that during coolingNote: 'rate of heat exchange' is plain-English for the source's 'whole-body heat-transfer coefficient'
The page saysconsistent with time at the surface being how it rewarms between hunting trips
The source saysthese results suggest that the main function of surfacing is the recovery of body temperatureNote: 'consistent with' preserves the source's own hedge ('these results suggest'); was 'lying flat in the sun', but the source says surfacing and warm surface water

Source
10

Sousa et al. 2016

Sousa et al. (2016). DNA barcoding identifies a cosmopolitan diet in the ocean sunfish. Scientific Reports.

The page sayssmaller sunfish eat mainly crustaceans and small fish
The source sayssmaller individuals feeding mainly on small crustaceans and teleost fishNote: backs stats.diet; keeps the source's 'mainly'
The page saysWhat a sunfish eats changes as it grows
The source sayswe found evidence for an ontogenetic shift in the diet, with smaller individuals feeding mainly on small crustaceans and teleost fish, whereas the diet of larger fish included more cnidarian species
The page saysIn a study of juveniles and sub-adults off southern Portugal, all 37 centimeters to 1.1 meters long
The source saysTotal length of the 100 sampled individuals ranged from 0.37 to 1.10 m, corresponding to juveniles and sub-adults ... sunfish captured in the tuna set-net off southern PortugalNote: reviewer: puts the diet study at its own scope; it sampled no adults
The page saysthe smaller fish ate mainly small crustaceans and fish from the seabed and coastal waters
The source sayssmaller individuals feeding mainly on small crustaceans and teleost fish ... smaller sunfish feed predominantly on benthic and on coastal pelagic speciesNote: 'from the seabed and coastal waters' is the source's 'benthic and ... coastal pelagic species'
The page sayswhile the larger ones relied on open-water prey and ate more kinds of jellyfish and their relatives
The source sayswhereas the diet of larger fish included more cnidarian species ... whereas larger fish depend on pelagic preyNote: 'jellyfish and their relatives' for cnidarians; 'more kinds' for 'more cnidarian species'. Was 'larger adults ... especially siphonophores': the study sampled no adults, and siphonophores come from a different study

Source
11

Sawai et al. 2017

Sawai et al. (2017). Redescription of the bump-head sunfish Mola alexandrini (Ranzani 1839), senior synonym of Mola ramsayi (Giglioli 1883), with designation of a neotype for Mola mola (Linnaeus 1758) (Tetraodontiformes: Molidae). Ichthyological Research.

The page saysThese species had long been confused for each other
The source saysas these two species have long been confused
The page saysa 2017 taxonomic study designated a fixed reference specimen for Mola mola to sort them out
The source saysA neotype of M. mola is designated for comparison with M. alexandrini, as these two species have long been confused.Note: 2017 is the paper's own publication year

Source
12

Johnson & Britz 2004

Johnson & Britz (2004). Leis' conundrum: Homology of the clavus of the ocean sunfishes. 2. Ontogeny of the median fins and axial skeleton of Ranzania laevis (Teleostei, Tetraodontiformes, Molidae). Journal of Morphology.

The page saysa study tracing its development in a related sunfish found it is formed from modified elements of the dorsal and anal fins, not a leftover tail fin: the caudal fin is lost in the sunfish family
The source saysthe molid clavus is unequivocally formed by modified elements of the dorsal and anal fin and that the caudal fin is lost in molidsNote: the study traced the slender sunfish Ranzania laevis (title) and concluded for the family Molidae

Source
13

Davenport et al. 2018

Davenport et al. (2018). The locomotor system of the ocean sunfish Mola mola (L.): role of gelatinous exoskeleton, horizontal septum, muscles and tendons. Journal of Anatomy.

The page saysThat gelatinous layer is roughly 90 percent water, threaded with a collagen and elastin meshwork
The source saysThe capsule is gelatinous (89.8% water) with a collagen and elastin meshwork.Note: 89.8% rounded to 'roughly 90 percent'
The page saysit houses the muscles that drive the dorsal and anal fins
The source saysIt provides two compartments, one for dorsal fin musculature and one for anal fin muscles

Source
14

Pan et al. 2016

Pan et al. (2016). The genome of the largest bony fish, ocean sunfish (Mola mola), provides insights into its fast growth rate. Gigascience.

The page sayscartilage-and-jelly fish
The source saysits endoskeleton is mainly composed of cartilageNote: the 'cartilage' half; the 'jelly' half is the subcutaneous gelatinous tissue, next claim
The page saysA body with no tail fin, steered by a stiff clavus rudder
The source saysits lack of a caudal fin, which is replaced by a broad and stiff lobeNote: backs 'stiff' (was 'rigid', which no source used)
The page saysThe skeleton is mostly cartilage
The source saysits endoskeleton is mainly composed of cartilageNote: reviewer cut the lead-in 'Most of that bulk isn't muscle or bone', which no source states
The page saysResearchers studying the sunfish genome found several genes tied to growth-hormone signaling showing signs of positive selection or sped-up evolution, which the study says might explain its fast growth rate
The source saysSeveral sunfish genes involved in the growth hormone and insulin-like growth factor 1 (GH/IGF1) axis signalling pathway were found to be under positive selection or accelerated evolution, which might explain its fast growth rate and large body sizeNote: was 'under unusually strong selection', which the source does not say

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.