Doug Perrine / Tiger shark (Galeocerdo cuvier) with remora or suckerfish clinging to flank, Bluefin trevally (Caranx melampygus), Racoon butterflyfish (Chaetodon lunula), Threadfin butterflyfish (Chaetodon auriga),...

David Fleetham / Lemon shark (Negaprion brevirostris) swimming with Remoras (Echeneidae), West End, Grand Bahamas, Atlantic Ocean.

David Fleetham / Spinner dolphin (Stenella longirostris) leaping out of the water, possibly to dislodge the Remora (Remora sp.) attached to its underside, Hawaii, Pacific Ocean.

David Fleetham / Lemon shark (Negaprion brevirostris) with Remora (Remora sp.) swimming underneath, West End, Grand Bahama, Atlantic Ocean.

Sirachai Arunrugstichai / Whale shark (Rhincodon typus), an endangered species, feeding on zooplankton in nutrient-rich murky water, being followed by a school of Cobia (Rachycentron canadum), Adang-Rawi Archipelago, Satun, An...

Doug Perrine / Oceanic whitetip shark (Carcharhinus longimanus) accompanied by Pilot fish (Naucrates ductor), and small Remora (Remora sp.) fish, Big Island, Hawaii, Pacific Ocean.

David Fleetham / Atlantic spotted dolphin (Stenella frontalis) two, one dolphin with Remora (Remora sp.) attached to its side, Western Atlantic Ocean, Bahamas, Caribbean.

Shane Gross / A large, pregnant Bull shark (Carcharhinus leucas) cruising over sandy seabed off Playa Del Carmen, Mexico. December.

Noemie Stroh / Green turtle (Chelonia mydas) feeding on a seagrass bed, with Remora (Echeneidae), Marsa Alam, Red Sea, Egypt.