Four new-to-science crab species have been discovered in The Philippines, on the island of Palawan, and one of them has a beautiful purple shell.

 

 

 

 

 

 

 

 

 

The so-called Insulamon palawanese crab may use its uniquely colored shell to help identify its own kind.

 

 

 

 

 

 

 

 

 

Crabs can discriminate colors. Therefore, it seems likely that the purple coloration is a function for their social behaviour, like when choosing mates.  Though the particular violet coloration might just have evolved by chance, and may not necessarily have a very specific function or reason aside from being a general visual signal for recognition, for other crabs of the species.

 

 

 

 

http://weeklyworldnews.com/headlines/47195/purple-crab/

http://news.yahoo.com/blogs/sideshow/species-purple-crab-discovered-philippines-223744176.html