The 'A'ama Crab is a rock crab that can stay under water for a long period of time.

'A'ama or Thin-Shelled Rock Crab
Grapsus tenuicrustatus

Description • The 'A'ama Crab is a greenish black and marked with faint striations and grows to about 3 inches. The dark color helps them to blend in well with the rocks. Their molted shells are often seen on the rocks and have turned bright red from the heat of the sun. Their legs are flat and long with little spikes for gripping to the rocks where the waves break.

Habitat • The A'ama Crab is widely found on rocky rocky shores along the splash zone. They quickly go into the water or into rocky crevices when they sense someone approaching.

Diet •. Feeds on algae found on the rocks in the splash zone.