Grapsus
Grapsus
Classification
- Phylum: Arthropoda
- Subphylum: Crustacea
- Class: Malacostraca
- Superorder: Eucarida
- Order: Decapoda
- Infraorder: Brachyura
- Family: Grapsidae
- Genus: Grapsus
Pronunciation
How to pronounce Grapsus: /ˈɡræpsəs/
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Images
Summary
Grapsus grapsus, commonly known as the red rock crab, is a prevalent crab species along the western coast of the Americas and is known for its agility and variability in coloration.
Physical Characteristics
Typically shaped crab with five pairs of legs; front two legs have small, blocky chelae; broad and flat legs with only tips touching substrate; round, flat carapace slightly longer than 8 cm (3.1 in). Young crabs black or dark brown; adults variable in colour including muted brownish-red, mottled, or spotted brown, pink, or yellow.
Identification Tips
Identify by the claw shape and coloration; takes on different colours depending on maturity and habitat.
Habitat
Lives among rocks at windy shores just above the limit of sea spray.
Distribution
Found along the Pacific coast of Mexico, Central America, and South America as far south as northern Peru; also found on Galápagos Islands; present on Atlantic coast of South America but replaced by Grapsus adscensionis in the eastern Atlantic.
Diet
Primarily feeds on algae; also consumes plant matter, sponges, crustaceans, fishes, young sea turtles, bird eggs and droppings, bat guano, and dead animals; may resort to cannibalism under high population density or food scarcity; larvae feed on phytoplankton.
Predators
Preyed upon by chain moray eel (Echidna catenata) and octopuses.
Ecosystem Role
Involved in a cleaning symbiosis with marine iguanas on the Galápagos Islands, by feeding on ticks.
Economic Impact
Not considered very edible by humans; sometimes used as bait by fishermen.
Evolution
Was first described by Carl Linnaeus in 1758 as 'Cancer grapsus'; differentiation from G. adscensionis established in 1990 due to morphological differences despite some debate on their separation as species.
Similar Taxa
Misconceptions
[No misconceptions explicitly stated in the text.]
Tags
- Grapsus
- red rock crab
- crustacean
- Brachyura