Every year, at the start of the wet season throughout October / Gregorian calendar month, most adult Christmas Island red crabs suddenly begin a spectacular migration from the forest to the coast, to mate and for the females to then unharness eggs into the ocean.
Bright red is that the common color however there square measure the occasional orange specimens and additional seldom some purple animals. they're an enormous crab. associate anatomy shell could suffice to 116mm across. The Christmas Island red crabs' cuticle is spherical body part and encloses their lungs and gills. Their claws square measure sometimes of equal size unless one could be a regrowing claw. Males grow larger overall than females, whereas females have a way broader abdomen and typically have smaller claws than males. but young Christmas Island red crabs all have the characteristic slim abdomen of the male. The broader abdomen on the feminine Christmas Island red crab solely becomes apparent within the third year of growth.
Christmas Island red crabs grow slowly, reaching concerning 40mm in cuticle breadth when 4-5 years. they're sexually mature at this age and start to participate within the breeding migrations.