Giant Freshwater Prawn

Macrobrachium rosenbergii

The giant freshwater prawn (Macrobrachium rosenbergii) is one of the largest freshwater prawns in the world, reaching up to 32 cm body length with males developing enormously elongated blue claws that can exceed the body length. It has a semi-transparent body with blue-grey coloring and distinctive long, toothed rostrum. Native to the Indo-Pacific region from Pakistan to northern Australia, it inhabits freshwater rivers, lakes, and estuarine waters at depths of 0 to 20 meters. Males exhibit dramatic claw development with dominance hierarchies based on claw size. This species is commercially important in aquaculture throughout Southeast Asia. Divers exploring freshwater springs, rivers, and cenotes in Southeast Asia regularly encounter these impressive prawns, whose large blue claws and territorial displays make them engaging subjects for underwater photography.