First Report of an Association Between Planes cyaneus (Decapoda:Grapsidae) and Loggerhead Sea Turtles in the Southwestern Atlantic Ocean

Most grapsid crabs are common members of intertidal or subtidal habitats in marine and estuarine waters. However, other grapsid species, in particular those belonging to the genus Planes, show different life history traits. This genus comprises three species which occur primarily in oceanic, pelagic habitats: Planes minutus (Linnaeus 1758), Planes cyaneus (Dana 1851) and Planes marinus (Rathbun 1914). These crabs are often found living on a wide variety of floating substrata, such as drifting algae (Sargassum), scyphozoans (Velella), gastropods (Janthina sp.) and the shells of Spirula cephalopods (Chase 1951; Davenport 1992; Geiselman 1983). Planes are also found on small pieces of polyurethane foam, rope, logs and even from an old refrigerator (Dellinger et al. 1997; Spivak & Bas 1999).