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title: "What the sources say about the Giant Freshwater Stingray | AnimalTracks.wiki"
description: "40 claims from the Giant Freshwater Stingray profile, each beside the words of the source that backs it."
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# What the sources say about the Giant Freshwater Stingray (*Urogymnus polylepis*)

> 40 claims from the Giant Freshwater Stingray profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Giant Freshwater Stingray](https://animaltracks.wiki/animals/giant-freshwater-stingray/)

## Campbell et al. (2023). A Review of the Conservation Status and Ecology of the Giant Freshwater Whipray (Urogymnus polylepis) across Its Known Distribution.

https://doi.org/10.3390/w15132487

| The page says | The source says |
| :--- | :--- |
| The 300-kilogram Mekong river phantom with a barbed tail spine and the record for the largest freshwater fish ever caught and officially recorded. | as of June 2022, a specimen from Cambodia became the largest freshwater fish ever caught and officially recorded ... a weight of 300 kg (Figure 1a) [2]. ... Near the base of the tail is a long, barbed spine [1] (note: 'Mekong river phantom' is a flourish) |
| A World-Record Weighed on the Mekong | a specimen from Cambodia became the largest freshwater fish ever caught and officially recorded |
| In June 2022, a female giant freshwater stingray (Urogymnus polylepis) was caught in the Mekong River in Stung Treng, Cambodia, with a disc width of 220 centimeters (7.2 feet), a total length of 398 centimeters (13 feet), and a weight of 300 kilograms (661 pounds) | Female caught in the Mekong River in Stung Treng, Cambodia, on 14 June 2022. Measurements: 220 cm disc width (DW), 220 cm disc length (DL), 398 cm total length (TL), 300 kg. (note: 220 cm = 7.2 ft, 398 cm = 13 ft, 300 kg = 661 lb) |
| A 2023 review of the species calls her the largest freshwater fish ever caught and officially recorded | as of June 2022, a specimen from Cambodia became the largest freshwater fish ever caught and officially recorded (note: the review is Campbell et al. 2023 itself; the Figure 1a caption identifies the record holder as the Stung Treng female) |
| Fishers from the Chao Phraya and Mekong basins have reported rays as large as 500 to 600 kilograms, but the largest one reliably measured, weighed, and documented is the Stung Treng female | The largest individual to be reliably measured, weighed, and documented has a disc width of 220 cm, a total length of 398 cm, and a weight of 300 kg (Figure 1a) [2]. Fishers from the Chao Phraya and Mekong basins reported individuals reaching even greater sizes, as large as 500–600 kg [1]. (note: Figure 1a is the Stung Treng female (see the claim above)) |
| The species is thought to reach a maximum age of 12 or more years and to mature at around three years old and 110 centimeters across the disc, with a generation length of 8 to 22 years | the giant freshwater whipray is thought to reach a maximum age of 12 or more years, have a generation length of 8–22 years, and mature at approximately three years and 110 cm disc width [9] (note: cites [9], the IUCN assessment; the 'thought to' hedge covers all three figures) |
| In India, the gut contents of ten individuals showed a preference for bony fish, shrimp, and crabs | Sen et al. [7] investigated 13 giant freshwater whiprays landed in Odisha and West Bengal between 2018 and 2021 ... Gut content analysis of ten individuals showed a preference for bony fishes, shrimps, and crabs [7]. |
| It's known from ten countries and several major river basins across eastern India and Southeast Asia, including the Ganges, the Mekong, and the Chao Phraya | The giant freshwater whipray is patchily distributed across eastern India and Southeast Asia [5]. ... The giant freshwater whipray is known in ten countries and several major river basins, including the Mekong, Chao Phraya, and Ganges [9]. |
| estuaries across ten countries in eastern India and Southeast Asia, including the Mekong, Chao Phraya, and Ganges basins | The species has been documented from inland rivers, estuaries, and coastal marine habitats [9]. ... The giant freshwater whipray is patchily distributed across eastern India and Southeast Asia [5]. ... The giant freshwater whipray is known in ten countries and several major river basins, including the Mekong, Chao Phraya, and Ganges [9]. |
| 2.2-meter disc width, a 300-kilogram record catch, and a long, barbed tail spine | The largest individual to be reliably measured, weighed, and documented has a disc width of 220 cm, a total length of 398 cm, and a weight of 300 kg (Figure 1a) [2]. ... Near the base of the tail is a long, barbed spine [1] (note: 220 cm = 2.2 m) |
| Some fishers track it in the sand. | some fishers target the species when they notice the whipray's tracks in the sand on sandbars |
| A 2021 survey in Khong District, Laos, found that some fishers target the ray when they spot its tracks in the sand on sandbars, or see one coming to shore to eat earthworms early in the rainy season | 2.5. Lao PDR ... a survey of fishers in Khong District in 2021 revealed that some fishers target the species when they notice the whipray's tracks in the sand on sandbars or individuals coming to shore to eat earthworms in the early rainy season. |
| Giving Birth When Caught | because of capture-induced parturition |
| Females give birth to live pups, with one to three considered a typical litter, and each pup is about 30 centimeters across the disc at birth | A viviparous species, females give birth to live pups, with litter sizes of 1–3 pups considered typical. Pups are approximately 30 cm in disc width at birth [9]. |
| Of 13 rays landed in Odisha and West Bengal, India, between 2018 and 2021, three pregnant females carried four to 15 developed embryos, considerably more than the litter size previously thought typical | Sen et al. [7] investigated 13 giant freshwater whiprays landed in Odisha and West Bengal between 2018 and 2021 ... three of the females were pregnant with pups. Pregnant females had a range of four to 15 developed embryos, which is considerably higher than what was previously thought to be the typical litter size for this species (1–2 pups) [9]. |
| Being caught can make a pregnant female give birth, a phenomenon called capture-induced parturition that has been documented several times in this species | because of capture-induced parturition, the population-level impact from fishing is likely higher than would be expected from the number of catches alone. This phenomenon has been documented multiple times for giant freshwater whipray [1,59]. (note: the first clause glosses the term capture-induced parturition (birth brought on by capture)) |
| Because of it, the population-level impact of fishing is likely higher than the number of catches alone would suggest | Adams et al. [59] noted that, because of capture-induced parturition, the population-level impact from fishing is likely higher than would be expected from the number of catches alone. |
| A Barbed Spine and a Falling Population | Near the base of the tail is a long, barbed spine [1] that can inflict painful wounds. (note: Heading; the falling population is the section's Red List claim ("population declines as high as 79%").) |
| Near the base of its long, whiplike tail sits a long, barbed spine that can inflict painful wounds | a broad, nearly circular body shape with a long, thin, whiplike tail [5]. Near the base of the tail is a long, barbed spine [1] that can inflict painful wounds. |
| because of population declines as high as 79 percent over the last century | The International Union for Conservation of Nature (IUCN) has assessed the giant freshwater whipray as endangered due to population declines as high as 79% over the last century [9]. (note: 'because of' renders the source's 'due to') |
| Key threats include high fishing pressure, bottom trawls, pollution, habitat degradation, and dams | Key threats to giant freshwater whipray across its range were identified as high fishing pressure, unmanaged artisanal fisheries, lack of legal protection, habitat degradation, pollution, dams, and bottom trawls, among others |
| The aquarium trade is a threat too: the species does not survive well in aquariums, so the trade requires a continual harvest from the wild | The aquarium trade has also been identified as a threat to this species, especially because it does not survive well in aquaria and thus requires continual harvest from the wild [9]. (note: 'so' renders the source's 'thus') |
| No. Until the early 2000s, scientists thought its range reached northern Australia and New Guinea, but molecular and body-shape work showed that the rays living there were a separate species, the freshwater whipray (Urogymnus dalyensis) | Until the early 2000s, its range was thought to include northern Australia and New Guinea, but molecular and morphometric work by Last and Manjaji-Matsumoto [3] showed that individuals in this region were a separate species, the freshwater whipray Urogymnus dalyensis. |
| weightKg: 200 | weights ranging from 95–300 kg (note: task #799; midpoint, rounded, of the 13 mature rays landed in India 2018-2021, the only adult weight sample on record. Heavy class (100 to 1000 kg) where the name guess gave Medium. Not in a curated matchup) |

## Himantura chaophraya (freshwater whipray). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Himantura_chaophraya/

| The page says | The source says |
| :--- | :--- |
| The Riverbed Buffet | Giant freshwater stingrays generally feed on river bottoms. |
| The giant freshwater stingray generally feeds on river bottoms, mainly on fish and invertebrates such as mollusks | Giant freshwater stingrays generally feed on river bottoms. ... Their diet consists mainly of benthic fishes and invertebrates. ... Animal Foods fish mollusks |
| Its two jaws act like crushing plates, with small teeth that keep chewing the food | Their mouth contains two jaws that act like crushing plates, and small teeth to continue chewing up food. |
| Mainly bottom-dwelling fish and invertebrates, including mollusks, shrimp, and crabs | Their diet consists mainly of benthic fishes and invertebrates. ... Animal Foods fish mollusks aquatic or marine worms aquatic crustaceans (note: shrimp and crabs are crustaceans; Campbell's gut-content study names them (claim above)) |
| it's typically found over sandy bottoms 5 to 20 meters down in large rivers | This species is typically found over sandy bottoms in large rivers, at depths of 5 to 20 meters. |
| Sandy river bottoms | This species is typically found over sandy bottoms in large rivers |
| Animal Diversity Web adds that the spine is serrated and has a venom gland | the ventral side has a spine with saw-like serrations and an associated venom gland |
| Animal Diversity Web reports no unprovoked attacks | There have been no reports of unprovoked attacks. |
| The ray can use its venomous tail spine in self-defense, and when fishers try to catch one, it whips that tail to get away | This species also has a strong, serrated, venomous spine on its tail, which can be used in self defense. ... When fishermen try to catch giant freshwater stingrays, they will whip their tail (bearing its large, serrated, venomous spine) to try and get away. |
| The same source says the spines have been reported to be strong enough to go through wooden boats | These spines have been reported to be strong enough to go through wooden boats. |
| Its dark back keeps predators swimming above from seeing it against the sand, while its pale belly hides its outline from predators below against the incoming sunlight | The dorsum is darkly colored, preventing predators swimming above them from seeing them against the sand, while the lighter colored belly obscures an individuals body outline from predators below, due to incoming sunlight. |
| Animal Diversity Web says this countershading and a sedentary lifestyle let even small rays blend in with the river bottom | Their countershaded color pattern and sedentary lifestyle offer even small individuals protection from larger predators, as they are able to blend in with the river bottom. |
| By blending in. | they are able to blend in with the river bottom |
| dangerLevel: High | When fishermen try to catch giant freshwater stingrays, they will whip their tail (bearing its large, serrated, venomous spine) to try and get away. (note: task #799; ADW also: "There have been no reports of unprovoked attacks." Dangerous when provoked, not on contact.) |
| a ray whose countershading and sedentary life let it vanish against the river bottom | Their countershaded color pattern and sedentary lifestyle offer even small individuals protection from larger predators, as they are able to blend in with the river bottom. (note: task #799, vibe.reason) |

## Grant et al. (2021). Urogymnus polylepis. The IUCN Red List of Threatened Species 2021: e.T195320A104294071.

https://doi.org/10.2305/iucn.uk.2021-2.rlts.t195320a104294071.en

| The page says | The source says |
| :--- | :--- |
| The species is Endangered on the IUCN Red List, assessed in 2021 | IUCN Red List category: Endangered (EN). Urogymnus polylepis (Bleeker, 1852), IUCN taxon 195320. (note: the category comes from GBIF's copy of the assessment; the 2021 date is the assessment's own year, in its DOI (iucn.uk.2021-2) and its title) |