 During the day , the reticulate whipray is generally inactive and spends much time resting motionless on the sea floor , sometimes buried in sand . In Shark Bay , Western Australia , this ray can be found resting singly or in small groups in very shallow water during high tide . Its lateral line extends to the tip of its extremely long tail , giving it advance warning of approaching predators such as bottlenose dolphins ( Tursiops aduncus ) and hammerhead sharks ( Sphyrna ) . The cowtail stingray ( Pastinachus sephen ) prefers to rest with the reticulate whipray over others of its own species , because the whiprays ' longer tails grant them superior predator detection . These mixed @-@ species groups often settle into a " rosette " with their tails pointing radially outward for maximum predator awareness . 
