Giant river prawn (Macrobrachium rosenbergii)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Arthropoda · Class: Malacostraca · Order: Decapoda · Family: Palaemonidae · Genus: Macrobrachium.

Accepted name: Macrobrachium rosenbergii · Authority: (De Man, 1879) · Taxonomic status: accepted · AphiaID: 220137.

Synonyms and superseded combinations recorded for this taxon: Macrobrachium rosenbergii schenkeli Johnson, 1973; Palaemon d’acqueti Sunier, 1925; Palaemon rosenbergii De Man, 1879; Palaemon whitei Sharp, 1893.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=220137 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Macrobrachium rosenbergii. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 34 cm · Depth range: 0–2 m · Habitat zone: benthic · Vulnerability index: 24 of 100 · Fishery importance: commercial.

SeaLifeBase notes: Wild post larvae migrate to down-stream near to the sea to a higher elevation freshwater waters streams (Ref. 82055). The native range of Macrobrachium rosenbergii actually consists of two separate species differing in adult morphological features. The actual M. rosenbergii occurs in northern Australia, Papua New Guinea, eastern Indonesia (east of Huxley's line including Bali) and the Philippines (includes Palawan). The second species is discovered as M. dacqueti (Sunier, 1925) which is actually the species extensively commercially fished and cultured. This species occurs in Asian mainland from Pakistan, India, Sri Lanka and southern China and to the western border of Huxley's line excluding Palawan, up to Borneo and Java (Ref. 110598, 110593). Coastal freshwater and estuarine (Ref. 97531), found in a mangrove (Ref. 121467). Survival rate and growth high at 0-15 ppt (Ref. 111574).

Source: SeaLifeBase species summary (SpecCode 24538) — https://www.sealifebase.se/summary/Macrobrachium-rosenbergii.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

491 georeferenced occurrence records for Macrobrachium rosenbergii are published through GBIF from 27 countries or marine areas. The map above plots 20 distinct locations from a sample of 491 records, omitting 118 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Malaysia (117); Bangladesh (103); India (72); Chinese Taipei (43); Brazil (34); Thailand (25); Indonesia (18); Australia (13); Mexico (10); Myanmar (9); Philippines (8); Martinique (7); China (4); Sri Lanka (4); Viet Nam (4).

Marine regions with a valid WoRMS distribution record: New Zealand Exclusive Economic Zone; Gulf of Mexico; French Polynesian Exclusive Economic Zone; Dominica; China; India; Indonesia; Iran; Archipel malais; Mexico; Peruvian part of the South Pacific Ocean; Formosa; Thailand; United States part of the Gulf of Mexico; Brazilian part of the South Atlantic Ocean; Micronesian part of the North Pacific Ocean; Venezuelan part of the North Atlantic Ocean; Northern Mariana Islands and Guam part of the Philippine Sea; Puerto Rican part of the North Atlantic Ocean; Puerto Rican Exclusive Economic Zone; Martinique; French Polynesia; Tahiti; Lesser Antilles; Chinese part of the Eastern China Sea; Chinese part of the South China Sea; Brazilian part of the North Atlantic Ocean; Tanzanian part of the Indian Ocean; Kenyan part of the Indian Ocean.

Source: GBIF Occurrence Search (taxonKey 2224546) — https://www.gbif.org/occurrence/search?taxon_key=2224546&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=220137 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Macrobrachium rosenbergii (De Man, 1879) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 197873) — https://www.iucnredlist.org/species/197873/0; GBIF IUCN Red List category endpoint (taxonKey 2224546) — https://api.gbif.org/v1/species/2224546/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

It is also known as the Malaysian prawn, freshwater scampi (India), or cherabin (Australia). Locally, it is known as golda chingri () in Bangladesh and India, udang galah in Indonesia and Malaysia, uwáng or uláng in the Philippines, (กุ้งแม่น้ำ) or (กุ้งก้ามกราม) in Thailand, and Thailand prawn in Southern China and Taiwan (Chinese: Tàiguó xiā 泰國蝦).

It is one of the biggest freshwater prawns in the world, and is widely cultivated in several countries for food. Due to accidental releases, the giant freshwater prawn has also been introduced to parts of Africa, China, Japan, New Zealand, the Americas, and the Caribbean.

M. rosenbergii can grow to a length over 30 cm, with total lengths of 34 cm for males and 26 cm for females. Females can be distinguished from males by their wider abdomens and smaller second pereiopods (walking legs), which bear the chelae (pincers). The genital openings are found on the body segments containing the fifth pereiopods in males and the third pereiopods in females.

They are predominantly brownish in colour, but can vary. Smaller individuals may be greenish and display faint vertical stripes. The rostrum is very prominent and contains 11 to 14 dorsal teeth and 8 to 11 ventral teeth. The first pair of walking legs is elongated and very thin, ending in delicate claws (chelipeds), which are used as feeding appendages. The second pair of walking legs is much larger and more powerful, especially in males. The movable claws of the second pair of walking legs are distinctively covered in dense bristles (setae) that give them a velvety appearance. The colour of the claws in males varies according to their social dominance.

Three different morphotypes of males exist, which correspond to their social dominance. The first stage is called "small male" (SM); this smallest stage has short, nearly translucent claws. If conditions allow, small males grow and metamorphose into "orange claws" (OC), which have large orange claws on their second chelipeds, which may have a length of 0.8 to 1.4 times their body size. OC males later may transform into the third and final stage, the "blue claw" (BC) males. These have blue claws, and their second chelipeds may become twice as long as their bodies.

Males of M. rosenbergii have a strict hierarchy; the territorial BC males dominate the OCs, which in turn dominate the SMs. The presence of BC males inhibits the growth of SMs and delays the metamorphosis of OCs into BCs; an OC keeps growing until it is larger than the largest BC male in its locale before transforming. All three male stages are sexually active, and females that have undergone their premating moult cooperate with any male to reproduce. BC males protect the females until their shells have hardened; OCs and SMs show no such behaviour.

In mating, the male deposits spermatophores on the underside of the female's thorax, between the walking legs. The female then extrudes eggs, which pass through the spermatophores. The female carries the fertilised eggs with her until they hatch; the time may vary, but is generally less than 3 weeks. Females lay 10,000–50,000 eggs up to five times per year.

From these eggs hatch zoeae, the first larval stage of crustaceans. They go through several larval stages in brackish water before metamorphosing into post-larvae, at which stage they are 0.28 - 0.39 in long and resemble adults. This metamorphosis usually takes place about 32 to 35 days after hatching. These post-larvae then migrate back into fresh water.

M. rosenbergii is widely eaten in Southeast Asian countries, its native range. They are also commonly used in indoor shrimping venues. The species is aquacultured throughout the tropics.

Professor Amir Sagi and his research group from the Ben-Gurion University of the Negev have found the IAG physiological sexual switch, and its associated gene expression in decapods investigating multigenic functions in crustacean reproduction and growth and the establishment of genome editing in prawns using application of CRISPR.

His group established monosex biotechnologies in crustacean culture including the application of temporal RNA interference (RNAi) in the field of aquaculture for all-male culture. Crustacean monosex technologies are applied in Vietnam, Thailand, China, Malaysia, Israel. He is a co-founder of the all-female culture biotech company Enzootic Ltd.

Prawns are efficient predators thus might serve as sustainable and responsible biocontrol agents over various invasive and pest species. The Sagi lab development of monosex prawn biotechnologies enables the application of responsible, efficient, and non-invasive biocontrol agents in various parts of the world.

Source: Wikipedia: Macrobrachium rosenbergii — https://en.wikipedia.org/wiki/Macrobrachium_rosenbergii (CC BY-SA 4.0). Accessed 2026-09-23.