Rusty Guard Crab

The Rusty Guard Crab (Trapezia bidentata) is a small marine crab that lives in a mutualistic relationship with corals of the Pocillopora and Acropora families. It is found in tropical and subtropical waters around the world, including the Indo-Pacific, 🌊 Red Sea, and 🌊 Caribbean Sea.

The Rusty Guard Crab is typically orange in color with red-brown markings on its legs and claws. It has a trapezoidal carapace (shell) and two large claws that it uses to defend its coral home from predators. The crab's eyes are reddish with black pupils.

The Rusty Guard Crab lives its entire life within the branches of its host coral. It provides a number of benefits to the coral, including:

• Defense from predators: The crab will aggressively defend its coral home from predators, such as the Crown-of-Thorns Starfish and Parrotfish.
• Cleaning: The crab will eat algae and other debris that can grow on the coral, helping to keep it healthy.
• Aeration: The crab's movements help to circulate water around the coral, which is important for its health.

In return, the coral provides the crab with a safe place to live and food in the form of algae and other organisms that grow on its branches.

The Rusty Guard Crab is a fascinating example of a mutualistic relationship between two different species. This relationship is important for the health of both the crab and the coral, and it plays a role in maintaining the biodiversity of coral reefs.