Giant Freshwater Prawn (Macrobrachium rosenbergii) Prawn Species Profile & Care Guide
Giant Freshwater prawns max out at nearly the size of a small lobster, with arms up to twice the length of their body so with their large size and active dispositions, this species is not suitable for the beginner aquarist.
Medium to large-sized Freshwater Prawns will also engage in predatory behaviours. Therefore choosing tankmates can be a tricky prospect and, for the most part, a species only tank is the safest bet.
Any inhabitants would have to be large enough to avoid the Giant Freshwater Shrimps predation but not big enough to eat the shrimp themselves. A well-armoured, herbivorous fish, such as a larger plecostomus, might be a better choice.
Keeping fish of equal size to the prawn is generally not advisable unless you're working with a very small species.
The Giant Freshwater Prawn are typically brownish in colour, but this can vary. Smaller individuals can be greenish in colour and present faint vertical stripes. The rostrum is very obvious and contains 8 to 11 ventral teeth and 11 to 14 dorsal teeth.
The first pair of pereiopods are elongated and very thin, ending in delicate claws which are used as feeding appendages. The second pair of pereiopods are much larger and more powerful, especially in males.
The adjustable claws of the second pair of pereiopods are distinctively covered in dense bristles that give it a velvety appearance. The colour of the claws in males varies according to their social dominance; however, blue seems to be the typical colour.
|Scientific Name||Macrobrachium rosenbergii|
|Other Names||Giant River Prawn, Malaysian Prawn, Freshwater Scampi, Cherabin|
|Aquarium Level||Bottom - Middle|
|Difficulty||Intermediate - Advanced|
|Best kept as||Trios|
|Lifespan||up to 3 years|
|Maximum Size||up to 30 cm|
|Temperature||57 - 82 ℉ (13.9 - 27.8 ℃)|
|PH||7.0 - 8.0|
|GH||2 - 9|
Origins of the Giant Freshwater Prawn
You can find the Giant Freshwater Prawn throughout the subtropical and tropical areas from Southeast Asia, India to Northern Australia.
Giant Freshwater Prawns have also been introduced to parts of China, Thailand, Africa, New Zealand, Japan and the Americas as well as the Caribbean. It is one of the largest Freshwater Prawns globally and is widely farmed in several countries for food.
These Prawns inhabit rivers, ponds, lakes and streams across every continent except Antarctica and Europe. Most species are amphidromous and require both freshwater and brackish water to complete their lifecycles.
Other Prawns of interest
Unlike other algae-eating and filter-feeding shrimp you can find in the hobby these days, Giant Freshwater Prawns are omnivores. Therefore, they require High quality dried foods such as granules, sinking pellets and wafers as well as meaty foods such as earthworm, bloodworms and brine shrimp in their diet.
Sexing the Giant Freshwater Prawn
It is Somewhat straight forward to distinguish male from female Giant Freshwater Prawns. Females tend to have broader abdomens and smaller second pereiopods than the males. Whereas males typically have more powerful and more extensive pereiopods than females.
Breeding the Giant Freshwater Prawn
It is very challenging to breed Giant Freshwater Shrimp in captivity because replicating the conditions they require requires a dedicated, scientific approach that, among other issues, amounts to a lot of hard work with limited yield.
In mating, the male coats spermatophores onto the female's thorax's underside, between the pereiopods. The female then expels eggs, which pass through the spermatophores. The female carries these fertilised eggs with her until they hatch. The time can vary but is generally less than three weeks. Females can lay up to 50,000 eggs five times per year.
The eggs hatch into zoeae, the first larval stage of crustaceans. They then go through several larval stages before metamorphosing into postlarvae, at which stage they resemble that of the adults.
This metamorphosis usually takes place around 32 to 35 days after hatching. These postlarvae then migrate back into freshwater.