Cyclograpsus lavauxi: Difference between revisions

The smooth shore crab, Cyclograpsus lavauxi, is a marine large-eyed crab of the family Grapsidae, endemic to New Zealand. Their carapace width is up to 28 mm.

This species is easily confused with the northern smooth shore crab, Cyclograpsus insularum, which has a much smaller range in New Zealand (between North Cape and East Cape), but similar habitat and eating habits. The smooth shore crab is larger and has a smoothly graded colour from brown/purple at the front, distinctly speckled, whereas C. insularum does not have the speckles. Its underside is white.

The smooth shore crab is common on rocky shores all around new Zealand, also in estuaries and mud flats, hiding under boulders. It has a smooth, elegantly curved carapace, and the eye orbits (sockets) are curved. It spends a great deal of time out of the water.

This crab's diet is normally tough seaweeds, but it will also scavenge and predate on worms.

Females start breeding at around 11 mm in width. Their egg-carying period runs from September to January. Their eggs are 0.32 mm across, coloured dark purple, becoming paler as development proceeds. Incubation time is about 8 weeks. Some females can produce two clutches of eggs in a season. Most crabs die after 2 to 3 years but some may live up to 5 years.

A rare species exists, Cyclograpsus whitei, which looks the same, but does not have the curved eye sockets.

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