Tahitian Prawn
ExploreAnimal
Tahitian Prawn
macrobrachium lar
The Tahitian Prawn, scientifically known as Macrobrachium lar, is an impressive freshwater crustacean native to the tropical streams and rivers of the Indo-Pacific region. This resilient decapod is highly regarded for its fascinating amphidromous life cycle, starting its life as larvae in brackish estuaries or the ocean before embarking on a challenging upstream migration into pristine mountain streams. Known for their distinctively long claws and active behavior, these prawns are vital ecological contributors, helping clean riverbeds by scavenging and keeping aquatic insect populations in check. They are highly adaptable creatures, capable of scaling wet rock faces to bypass waterfalls during their migration, which makes them a true marvel of river ecosystems.
Habitat: Typically found in clear, fast-flowing freshwater streams and rivers with rocky substrates and overhanging vegetation throughout the Indo-Pacific islands.
Appearance
This large prawn is characterized by its robust, marbled dark brown to deep bluish-black body, often with subtle lighter patterning along the abdominal segments. Mature males are particularly striking, possessing an exceptionally long and robust second pair of walking legs modified into powerful claws, which are often uneven in size and display a blue-grey coloration. The carapace is smooth and tough, while its long, sensitive antennae extend forward to detect prey and predators. Fully grown specimens typically measure between 10 to 18 centimeters in length, excluding their claws.
KingdomAnimaliaPhylumArthropodaClassMalacostracaOrderDecapodaFamilyPalaemonidaeGenusMacrobrachium
Category
AnimalRarity
Common
Danger
1/5 · Very low
Snaps
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Interesting facts
Despite living in freshwater as adults, their larvae cannot survive without saltwater, requiring a journey to the ocean and back.
During upstream migration, juvenile Tahitian Prawns can climb vertical rock faces of waterfalls by gripping onto wet moss and algae.
Males have highly asymmetrical claws, with one often being much larger and stronger, used for defending territories and courting females.
Special abilities
Ability
Waterfall Climbing
They can crawl out of the water on wet rock surfaces to climb up steep waterfalls during upstream migration.
Ability
Amphidromous Migration
Larvae develop in saltwater before juveniles migrate back to freshwater rivers to mature.
Ability
Rapid Tail-Flip Escape
They rapidly flex their muscular abdomen to swim backward at high speeds when threatened.
Measurements & details
- Length
- 10-18 cm
- Weight
- 0.05-0.15 kg
- Lifespan
- 2-4 years
- Clutch Size
- 5000-20000
- Incubation
- 15-24 days
- Migration Distance
- 15 km
Diet & Feeding
A generalist feeder that consumes a mixture of detritus, aquatic insects, algae, and small invertebrates found on stream beds.
Age differences: Larvae feed primarily on marine plankton, whereas adults transition to scavenging and opportunistic predation in freshwater habitats.
Primary Foods
- Algae
- Aquatic insects
- Decaying leaf litter
- Small fish
- Snail larvae
Foraging Method
- Foraging
Ecological connections
eaten by
Giant Mottled Eel
Anguilla marmorata
Preyed upon by large eels inhabiting the same freshwater streams.
hunts
Red-rimmed Melania
Melanoides tuberculata
Feeds opportunistically on small freshwater snails along the riverbed.
competitor
Atyid Shrimp
Atyopsis spinipes
Competes for shelter and food sources in riverine rock crevices.
Traits
No trait badges are assigned for this object yet.
Also known as
No aliases listed yet.
Collections
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Safety
Danger
1/5 · Very low
No special safety notes yet.
Frequently Asked Questions
How to identify Tahitian Prawn?
The easiest way to identify Tahitian Prawn is to use the Snappit nature identifier app.
How long is Tahitian Prawn?
10-18 cm
How much does Tahitian Prawn weigh?
0.05-0.15 kg
How long does Tahitian Prawn live?
2-4 years
What does Tahitian Prawn eat?
A generalist feeder that consumes a mixture of detritus, aquatic insects, algae, and small invertebrates found on stream beds.
Where is Tahitian Prawn usually found?
Typically found in clear, fast-flowing freshwater streams and rivers with rocky substrates and overhanging vegetation throughout the Indo-Pacific islands.
How does Tahitian Prawn hunt?
Foraging
How many eggs does Tahitian Prawn lay?
5000-20000
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