Rock Crab

Rock Crab

Scientific name: Cancer irroratus

Phylum: Arthropoda

Subphylum: Crustacea

Class : Malacostraca

Order: Decapoda

Description: The shell of rock crab is broadly oval, with nine wide smooth marginal teeth. Its color is usually yellowish freckled with reddish or purplish brown. Rock crabs can reach the size of 131mm.

Distribution: Rock crabs live in inter-tidal and mostly sub-tidal, extending to 780m on all types of bottoms.

Locomotion: Rock crabs primarily move forward by flexion and extension of limbs.

Food gathering: Rock crabs are predatory. They grasp their prey with enlarged front claws followed by tearing, grinding or shearing with various mouth parts. They eat live prey but also scavenge on dead animals.

Gas exchange: Rock Crabs have gills in branchial chambers for gas exchange. They use gill bailers (elongate exopods) that vibrate to create ventilating currents.

Reproduction: Scattered individuals find one another during mating season using same environmental cue. Sperm deposited directly into oviduct and females brood eggs until hatching occurs.

Interesting facts: Crabs have tails that are folded underneath their body. Males have pointed triangular tails, where as females have spade shaped tails. The spade shape helps the female carry eggs around during the spawning season.


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