Bottlenose dolphin and remora. View of a remora (family Echeneidae) attached to the underside of a swimming bottlenose dolphin (Tursiops truncatus). The bottlenose dolphin can reach a length of four metres, although females are smaller than males. They are highly intelligent, and in the wild they work in teams, plan hunting strategies and have an intricate social system. Remora, or suckerfish, have a symbiotic relationship with many large sea animals. They attached themselves to their host using a sucker on top of their head. The clean the host's skin of parasites and eats left-over scraps. The host in turn provides protection for the remora. Photographed in the Gulf of California, Mexico.