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Giant IsopodBathynomus giganteus

Every figure, record and mechanism on the Giant Isopod profile was written from a source, and this is the working table behind it: 43 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

McClain et al. 2015

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

The page sayshas been reported to survive eight weeks between meals in an aquarium
The source saysSpecimens in aquaria have survived 8 weeks between feedings ( Cocke, 1986 )Note: The figure comes from Cocke (1986), an article in the hobby magazine Tropical Fish Hobbyist, cited by McClain et al.; 'has been reported' carries that attribution.
The page saysContinental slopes of the Gulf of Mexico and Caribbean Sea, typically 310 to 1,800 meters down, less commonly the US Atlantic coast as far north as Georgia
The source saysBathynomus giganteus are abundant scavengers distributed throughout the Gulf of Mexico and Caribbean Sea on upper- and mid-continental slopes at depths typically ranging from 310 to 1800 m ... Though less abundant, giant isopods are also found along the eastern coast of the United States as far north as Georgia ( Lowry & Dempsey, 2006 ).
The page saysA scavenger that can also hunt live prey
The source saysBathynomus giganteus is a scavenger ( Holthuis & Mikulka, 1972 ; Cocke, 1986 ; Briones-Fourzán & Lozano-Álvarez, 1991 ) or facultative predator ( Holthuis & Mikulka, 1972 ; Briones-Fourzán & Lozano-Álvarez, 1991 ).Note: 'facultative predator' rendered as 'can also hunt live prey'.
The page saysA big body that can hold large fat reserves, which may help it fast when food is scarce and sporadic.
The source saysThus, the large size of B. giganteus may serve as an adaptation to low and sporadic food availability by increasing fasting potential because greater fat reserves can be maintained
The page saysNot Evaluated
The source saysThe giant deep-sea isopod Bathynomus giganteus is the largest known isopod species.Note: No IUCN Red List assessment exists for Bathynomus giganteus: GBIF's copy of the Red List has no category for the name and Crossref has no assessment DOI, checked 2026-09-16. Boos et al. (2021) assessed its extinction risk as Least Concern, but that is the authors' own assessment, not a Red List one.
The page saysA 2015 study of ocean giants called it the largest known isopod species.
The source saysThe giant deep-sea isopod Bathynomus giganteus is the largest known isopod species.
The page saysIt lives on the continental slopes of the Gulf of Mexico and the Caribbean Sea, typically 310 to 1,800 meters down
The source saysBathynomus giganteus are abundant scavengers distributed throughout the Gulf of Mexico and Caribbean Sea on upper- and mid-continental slopes at depths typically ranging from 310 to 1800 m ... Though less abundant, giant isopods are also found along the eastern coast of the United States as far north as Georgia ( Lowry & Dempsey, 2006 ).Note: The closing clause 'where the seafloor drops away from the edge of the land' defines a continental slope and states nothing about the species.
The page saysIt is less common along the US Atlantic coast, as far north as Georgia.
The source saysBathynomus giganteus are abundant scavengers distributed throughout the Gulf of Mexico and Caribbean Sea on upper- and mid-continental slopes at depths typically ranging from 310 to 1800 m ... Though less abundant, giant isopods are also found along the eastern coast of the United States as far north as Georgia ( Lowry & Dempsey, 2006 ).
The page saysAs of that 2015 study, the largest giant isopod documented in the scientific literature measured 50 centimeters (about 20 inches).
The source saysThe largest giant isopod documented in the scientific literature is a more conservative 50 cm ( Lowry & Dempsey, 2006 ).Note: 50 cm converted to about 20 inches (19.7 in). Dated to the study because it is a record.
The page saysA 76-centimeter giant was reported in the popular media, but it could not be confirmed with an actual measurement.
The source saysAn individual measuring 76 cm in length was reported in the popular media but cannot be confirmed with actual measurements ( Daily Mail Reporter, 2010 ).
The page saysGiant isopods kept in aquariums have survived eight weeks between feedings
The source saysSpecimens in aquaria have survived 8 weeks between feedings ( Cocke, 1986 )
The page saysaccording to a 1986 aquarium magazine article.
The source saysCocke (1986) Cocke BT. Deep-sea isopods in aquaria. Tropical Fish Hobbyist.Note: Cocke (1986), the source McClain et al. cite for the 8-week figure, is an article in Tropical Fish Hobbyist, an aquarium hobby magazine.
The page saysScientists think their large size may be an adaptation to food that is scarce and sporadic: a bigger body can hold bigger fat reserves, so it can fast for longer.
The source saysThus, the large size of B. giganteus may serve as an adaptation to low and sporadic food availability by increasing fasting potential because greater fat reserves can be maintained
The page saysGiant isopods do store large amounts of fat in their hepatopancreas
The source saysFurther support for this hypothesis is the large quantities of lipid reserves in the hepatopancreas ( Steves, 1969 ) and fat bodies ( Biesot et al., 1999 ) of this isopod.Note: 'lipid' rendered as 'fat'. 'a digestive gland' glosses the term; Biesot et al. (1999) in the same reference list call it the midgut gland.
The page saysA bigger body also lets an animal search a larger area for food, which matters to scavengers and predators alike.
The source saysLarger size also confers a greater foraging area, which is important for both scavengers and predators.
The page saysGiant isopods are scavengers, feeding on animals that are already dead, and facultative predators, which means they can hunt live prey but do not depend on it.
The source saysBathynomus giganteus is a scavenger ( Holthuis & Mikulka, 1972 ; Cocke, 1986 ; Briones-Fourzán & Lozano-Álvarez, 1991 ) or facultative predator ( Holthuis & Mikulka, 1972 ; Briones-Fourzán & Lozano-Álvarez, 1991 ).Note: 'feeding on animals that are already dead' and 'can hunt live prey but do not depend on it' define scavenger and facultative predator.
The page saysGiant isopods (Bathynomus giganteus) kept in aquariums have survived eight weeks between feedings
The source saysSpecimens in aquaria have survived 8 weeks between feedings ( Cocke, 1986 )
The page saysaccording to a 1986 aquarium magazine article.
The source saysCocke (1986) Cocke BT. Deep-sea isopods in aquaria. Tropical Fish Hobbyist.Note: Cocke (1986), the source McClain et al. cite for the 8-week figure, is an article in Tropical Fish Hobbyist, an aquarium hobby magazine.
The page saysScientists think their large size may help them fast when food is scarce and sporadic, because a bigger body can hold bigger fat reserves.
The source saysThus, the large size of B. giganteus may serve as an adaptation to low and sporadic food availability by increasing fasting potential because greater fat reserves can be maintained
The page saysAs of a 2015 study, the largest giant isopod documented in the scientific literature measured 50 centimeters (about 20 inches).
The source saysThe largest giant isopod documented in the scientific literature is a more conservative 50 cm ( Lowry & Dempsey, 2006 ).Note: 50 cm converted to about 20 inches (19.7 in).
The page saysA 76-centimeter giant was reported in the popular media, but it could not be confirmed with an actual measurement.
The source saysAn individual measuring 76 cm in length was reported in the popular media but cannot be confirmed with actual measurements ( Daily Mail Reporter, 2010 ).
The page saysGiant isopods are scavengers, which means they feed on animals that are already dead.
The source saysBathynomus giganteus is a scavenger ( Holthuis & Mikulka, 1972 ; Cocke, 1986 ; Briones-Fourzán & Lozano-Álvarez, 1991 ) or facultative predator ( Holthuis & Mikulka, 1972 ; Briones-Fourzán & Lozano-Álvarez, 1991 ).Note: The second clause defines scavenger.
The page saysThey are also facultative predators: they can hunt live prey, but they do not depend on it.
The source saysBathynomus giganteus is a scavenger ( Holthuis & Mikulka, 1972 ; Cocke, 1986 ; Briones-Fourzán & Lozano-Álvarez, 1991 ) or facultative predator ( Holthuis & Mikulka, 1972 ; Briones-Fourzán & Lozano-Álvarez, 1991 ).Note: The clause after the colon defines facultative predator.
The page sayssaid to last eight weeks between meals in aquariums
The source saysSpecimens in aquaria have survived 8 weeks between feedings ( Cocke, 1986 )Note: From Cocke (1986), a hobby-magazine article cited by McClain et al.; 'said to' carries that attribution.

Source
02

Boos, Scalco & Araujo 2021

Boos, Scalco & Araujo (2021). Biological and ecological traits of Bathynomus giganteus and Bathynomus miyarei (Crustacea: Isopoda): Contribution to the conservation of deep-sea in southern Brazil. Aquatic Conservation: Marine and Freshwater Ecosystems.

The page saysdeep water off southern Brazil
The source saysBathynomus giganteus (663 specimens) and B. miyarei (649 specimens) were collected during five research cruises involving 265 h of sampling effort during 32 fishing operations of circular pots, baited traps, ranging from 400 and 1,000 m deep, between 26 and 29°S adjacent to the Brazilian coast. ... Bathynomus giganteus were collected between 600 m and 1,000 m depth
The page saysA 2021 study caught 663 giant isopods in baited traps off southern Brazil, between 600 and 1,000 meters deep.
The source saysBathynomus giganteus (663 specimens) and B. miyarei (649 specimens) were collected during five research cruises involving 265 h of sampling effort during 32 fishing operations of circular pots, baited traps, ranging from 400 and 1,000 m deep, between 26 and 29°S adjacent to the Brazilian coast. ... Bathynomus giganteus were collected between 600 m and 1,000 m depth
The page saysIt estimated that males there mature at about 34 centimeters long and live about 6 years
The source saysThe sexual maturity of B. giganteus was estimated at 340–345 mm total length for males and between 280–290 mm for females. ... The longevity of B. giganteus was estimated at 6 years for males and 7.7 years for females.Note: 340-345 mm rounded to about 34 cm. Scope kept to the southern Brazil sample the study estimated from.
The page sayswhile females mature at 28 to 29 centimeters and live about 7.7 years
The source saysThe sexual maturity of B. giganteus was estimated at 340–345 mm total length for males and between 280–290 mm for females. ... The longevity of B. giganteus was estimated at 6 years for males and 7.7 years for females.Note: 280-290 mm converted to 28 to 29 cm. 'estimated' in the preceding clause governs this one.

Source
03

Chamberlain, Meyer-Rochow & Dossert 1986

Chamberlain, Meyer-Rochow & Dossert (1986). Morphology of the compound eye of the giant deep-sea isopod Bathynomus giganteus. Journal of Morphology.

The page sayswith about 3,500 lenses in each eye
The source saysEach eye contains about 3,500 ommatidia in animals of body lengths from 22.5 cm to 37.5 cm. ... The dioptric elements in each ommatidium consist of a laminar corneaNote: An ommatidium's dioptric (light-focusing) elements, its cornea and crystalline cone, rendered as a lens. Measured in animals 22.5 to 37.5 cm long.
The page saysA 1986 study described the eyes of four giant isopods kept alive in a lab.
The source saysThe structural organization of the compound eye of the largest known isopod, Bathynomus giganteus, is described from four specimens maintained in the laboratory for as long as two months.
The page saysIn animals 22.5 to 37.5 centimeters long, each of the two compound eyes held about 3,500 ommatidia
The source saysEach eye contains about 3,500 ommatidia in animals of body lengths from 22.5 cm to 37.5 cm.
The page saystiny units that each have their own lens and light-sensing cells
The source saysThe dioptric elements in each ommatidium consist of a laminar cornea, which is flat externally and convex internally, and a bipartite crystalline cone. Sometimes seven and sometimes eight retinular cells closely appose the proximal tip of the cone and bear the microvilli of the rhabdom.Note: The cornea and cone (dioptric elements) rendered as a lens; the retinular cells are the photoreceptors the abstract's last sentence names.
The page saysBeing brought up from the deep into daylight appeared to cause permanent damage to the light-sensing cells of these animals.
The source saysAnimals were fixed both in light within a week of being brought from depth into daylight ... Exposure to natural daylight appears to cause irreversible structural damage to the photoreceptors of these animals.Note: 'photoreceptors' rendered as 'light-sensing cells', 'irreversible' as 'permanent'.

Source
04

Pless et al. 2003

Pless et al. (2003). Latent phenoloxidase activity and N-terminal amino acid sequence of hemocyanin from Bathynomus giganteus, a primitive crustacean. Archives of Biochemistry and Biophysics.

The page saysHemocyanin is the protein that carries oxygen in a giant isopod's blood.
The source saysThe hemocyanin of this primitive crustacean may fulfill dual functions, both as oxygen carrier and as the phenoloxidase crucial for host defense.Note: The abstract's hedge ('may') applies to the dual role; hemocyanin as oxygen carrier is the premise. 'blood' stands for hemolymph.
The page saysIn a 2003 lab study, purified hemocyanin from giant isopods worked as phenoloxidase, an enzyme, once a chemical was added to switch it on.
The source sayspurified hemocyanin from B. giganteus exhibited phenoloxidase activity in the presence of sodium dodecyl sulfate. Although a natural activator has not yet been identifiedNote: Sodium dodecyl sulfate rendered as 'a chemical ... to switch it on', since the abstract contrasts it with a natural activator.
The page saysEarly measurements of the enzyme were consistent with an important role in the animal's immune system, though the natural switch had not been found.
The source saysAlthough a natural activator has not yet been identified, a preliminary study of the enzyme indicated a K(m) of 5mM for dopamine and an initial rate of 0.1 micromol per min per mg protein, values consistent with a significant role for this enzyme in the innate immune system of B. giganteus.
The page saysThe researchers suggested one molecule may do two jobs: carrying oxygen and defending the body.
The source saysThe hemocyanin of this primitive crustacean may fulfill dual functions, both as oxygen carrier and as the phenoloxidase crucial for host defense.
The page saysOne Molecule, Maybe Two Jobs
The source saysThe hemocyanin of this primitive crustacean may fulfill dual functions, both as oxygen carrier and as the phenoloxidase crucial for host defense.

Source
05

Chaves-Aguilar et al. 2025

Chaves-Aguilar et al. (2025). Caracterización biológica del isópodo gigante (Bathynomus giganteus) en aguas profundas del Caribe colombiano. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales.

The page saystags: benthic
The source saysEste isópodo habita fondos blandos ... El cuerpo de B. giganteus es aplanado dorsoventralmente, lo que le permite moverse con facilidad sobre el sedimento del fondo marino y enterrarse en él.Note: Benthic is "living on the bottom of aquatic bodies, crawling over sediments": the source has B. giganteus living on soft bottoms and moving over seafloor sediment. Replaces the abyssal tag removed in #470, which the 310-1,800 m continental-slope range contradicted.

Source
06

NOAA Ocean Exploration

Giant Isopod. NOAA Ocean Exploration.

The page saysone was seen snacking on a fish head
The source saysThe other giant isopod we encountered was observed snacking on a fish head .
The page saysis a deep-sea scavenger and a close relative of the pill bugs, roly-polies and sowbugs found in houses and gardens, but much, much larger
The source saysThese deep-sea scavengers are close relatives of the pill bugs, rolly pollies, and sowbugs found in houses and gardens, but Bathynomus giganteus is much, much larger
The page saysA NOAA expedition about 65 kilometers southeast of Key West, Florida, saw one snacking on a fish head in 2019.
The source saysThis was one of two giant isopods ( Bathynomous giganteus ) seen while exploring a site about 65 kilometers (40 miles) southeast of Key West, Florida, as part of the 2019 Southeastern U.S. Deep-sea Exploration . The other giant isopod we encountered was observed snacking on a fish head .
The page saysGiant isopods are deep-sea scavengers and close relatives of the pill bugs, roly-polies and sowbugs found in houses and gardens, but much, much larger.
The source saysThese deep-sea scavengers are close relatives of the pill bugs, rolly pollies, and sowbugs found in houses and gardens, but Bathynomus giganteus is much, much larger

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.