I love these guys. The Blue Swimming Crab, with their pointy-edged carapace and brave defiant stance when approached make them appear invincible. Such bold little creatures. Then, if you are brave yourself and poke them, they get all flustered and with their rapidly rotating back pair of legs swim across the sea floor and bury themselves in a sand patch. The pictured crab was seen while snorkelling at night off the shores of Andros Island in the Bahamas where they are fairly common. Here in Anguilla they are not as abundant, although you can sometimes see them while standing on the wooden jetty at Sandy Ground. Paddlers watch your toes! (only joking, they would rather swim off than give you a nip).
The species present in the Caribbean Sea are different from the Blue Swimming Crab found in the Indian and West Pacific Ocean (as well as those who have recently arrived in the Mediterranean Sea through Lessepsian Migration). Those in the Caribbean are from the genera Callinectes which are smaller than their Pacific cousins, usually less obviously blue, and difficult to identify down to species level.
Originally posted on Instagram @sea_anguilla with the text: Blue Swimming Crab photographed at night. These little guys can often be seen swimming around the shallows in Sandy Ground, although their paler colour means they are likely a different species to that pictured.