Giant freshwater stingray
Fish · Last reviewed 2026-08-10
One of the largest freshwater fish in the world, an Endangered Mekong and Southeast Asian river ray with a serrated venomous barb capable of severe injury.
Safety
Venomous and spined species — Can cause serious injury or death
The tail barb is long, serrated and venomous, and can penetrate deeply. Injuries from large freshwater stingrays have been fatal, and the serrations cause severe tissue damage on withdrawal.
What reduces it: Keep the tail controlled and never position yourself over it. Handle the fish in the water with experienced help, and treat any sting as a medical emergency requiring immediate professional care.
The giant freshwater stingray is among the largest freshwater fish on earth — a broad, disc-shaped ray of the great rivers of Southeast Asia and parts of South Asia, reaching sizes measured in hundreds of kilograms.
It is Endangered. Its rivers — the Mekong, Chao Phraya, Mahakam and others — are among the most heavily dammed, fished and polluted large river systems in the world, and the species is slow-growing, late-maturing and produces very few young. It is a textbook case of a large freshwater animal that cannot absorb pressure.
It carries a long serrated barb near the base of the tail. This is the one species in this catalogue whose sting has caused human fatalities, and the handling section is not a formality.
Identification
FishingHQ holds no photograph of this species whose identity and licensing it can vouch for, so it is not showing one. Misidentified fish photographs teach identification wrongly, and a picture with an unchecked caption would be worse than none. The identification points below are what to look at instead.
- Scientific name
- Urogymnus polylepis
- Family
- Dasyatidae
- Water
- Freshwater, Brackish
- Conservation status
- Endangered
- Regions
- South-East Asia, South Asia
- Very large oval to circular disc, plain grey-brown above and white below with a broad dark margin.
- A long whip-like tail without a caudal fin, carrying a serrated barb near its base.
- Fine denticles over the upper surface giving a rough texture.
- Eyes small relative to the disc, with spiracles immediately behind them.
Size
- Typical
- Most rod-caught fish 30–100 kg (66–220 lb)
- Large
- 150–300 kg (330–660 lb)
Exceptional: FishBase records a maximum of 240 cm and 600 kg
Lifecycle and reproduction
Very slow-growing, late-maturing and long-lived, producing very small numbers of live young. Reproductive output is among the lowest of any large freshwater fish, which is why the species cannot recover quickly from decline.
Viviparous, with the female nourishing a small number of embryos internally and giving birth to live young. Litters are very small and gestation is long, so each adult female matters disproportionately.
Feeding and senses
Takes bottom-dwelling fish, crustaceans and molluscs from soft river substrate, locating buried prey and pinning it beneath the disc.
Locates prey by electroreception and smell over soft riverbed, since the eyes are on top of the disc and the mouth beneath. Vision plays almost no part in feeding.
Through the year
Moves within river systems with seasonal water levels, using deep pools in low water. Some populations move into estuarine conditions.
Distribution
Asia and Oceania: Mekong and Chao Phraya basins; also from eastern Borneo, New Guinea and northern Australia
This is a biological range — where the species occurs, not a prediction that you will catch one. To browse the fishing geography FishingHQ holds, start at fishing places.
Why anglers care
A specialist target in Thailand and neighbouring countries, fished with heavy tackle and bait on the bottom in deep river pools, largely through managed fisheries operating on a strict release basis. Its significance is as one of the largest freshwater fish an angler can encounter and as a serious conservation concern. FishingHQ does not state what any rule is; access, permits and handling requirements vary and must be checked locally.
Handling and returning
The barb is the primary hazard and can cause fatal injury. Fish of this size should be handled in the water by people who know the species, with the tail controlled at all times. Never stand over the tail, never attempt to lift the fish by the tail, and keep the ray in water throughout unhooking. Release requires supporting the disc and allowing the fish to swim off under its own power.
A barbed tail on a very large animal, and the only correct answer is distance
This is the most dangerous animal in the freshwater part of this catalogue and the handling advice is genuinely different in kind: the objective is not to handle it well but to handle it as little as physically possible.
THE WEAPON. A serrated venomous barb on the tail, which on a large individual is a substantial spine capable of penetrating deeply. The tail is flexible and the strike is a whipping motion over the back — which means the danger zone is above and behind the animal, exactly where somebody leaning over to unhook it is standing. Stingray injuries are frequently to the leg, the abdomen or the chest rather than the hand, and they are serious: deep, envenomated, and in the worst cases penetrating.
SO THE PROCEDURE IS FIXED AND IT IS NOT NEGOTIABLE. Never lift one. Never stand over the tail. Never allow the animal onto a boat. Work from the side or from in front, in the water, with the animal kept in the shallows and the tail attended to by somebody whose only job is watching it. Experienced operations for this species restrain the tail specifically before anyone approaches the head.
USE LONG TOOLS AND CUT THE TRACE if there is any doubt. A hook is a much smaller problem than a barb.
IF SOMEBODY IS BARBED: this is a medical emergency, not a first-aid matter. Hot water immersion is the standard field measure for the venom's pain, the wound is likely to retain barb fragments and sheath material, and penetrating trunk injuries need a hospital immediately. Fishing for this species in remote water without a plan for that is the actual risk being taken.
AND THE ANIMAL IS THREATENED. Large individuals are old, the species is in decline across its range, and it should be released with the minimum possible intervention — which happily is the same thing that keeps people safe.
Authoritative guidance
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
- The IUCN Red List of Threatened Species — International Union for Conservation of Nature (Conservation authority)Relied on for: Conservation status and population decline for this species, supporting minimal-intervention release.States this directlyCitation checked — the work exists and is described correctly
Where to go next
How it is caught
What these connections rest on (1)
Practitioner consensus — 1 connection
Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.
Ledgering
A practitioner claim about how Urogymnus polylepis is commonly fished, following from where and how it feeds.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated practitioner accounts of fishing for giant freshwater stingray.Citation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Practitioner treatment of the methods used for giant freshwater stingray and comparable species.Citation checked — the work exists and is described correctly
Where it lives
What these connections rest on (1)
Scientific evidence — 1 connection
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
Lowland rivers
A habitat association for Urogymnus polylepis taken from the environment and distribution data on its FishBase summary.
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: The environment, depth range and habitat description recorded for Urogymnus polylepis.States this directlyPassage read and verified
Where you will find it
What these connections rest on (1)
Scientific evidence — 1 connection
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
The Mekong system
A distribution association between an animal and a described water body, which is what the `inhabits` predicate is for — the kind of water rather than a named mark.
- The IUCN Red List of Threatened Species — International Union for Conservation of Nature (Conservation authority)Relied on for: Assessment and habitat account for the species, including the river or lake system it occupies and the pressures acting on it.States this directlyCitation checked — the work exists and is described correctly
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Distribution, habitat association, size and life history recorded for the species in the system concerned.States this directlyPassage read and verified
More fish
Not related to this page — just the rest of the section, because this record connects to very little and a short page should still lead somewhere.
Sources for this page
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Family, maximum size, depth and environment, distribution and the IUCN assessment for Urogymnus polylepis.States this directlyPassage read and verified
- The IUCN Red List of Threatened Species — International Union for Conservation of Nature (Conservation authority)Relied on for: The Endangered assessment for Urogymnus polylepis, assessed 25 January 2021.States this directlyCitation checked — the work exists and is described correctly
How FishingHQ labels evidence is explained in the evidence policy.