David Fleetham / Remora (Echeneis naucrates) free swimming, Beqa Lagoon, Fiji

David Fleetham / Remora (Echeneis naucrates) free swimming shoal, Beqa Lagoon, Fiji

David Fleetham / Sharks' teeth are not attached to the jaw, but embedded in the flesh. Lemon Shark (Negaprion brevirostris) shedding a front tooth, with remora fish. West End, Grand Bahamas, Atlantic Ocean.

David Fleetham / Tiger Shark (Galeocerdo cuvier) with attendant remora fish. Bahamas, Atlantic Ocean.

David Fleetham / Photographer / diver watching lemon shark (Negaprion brevirostris) with remoras. West End, Grand Bahamas, Atlantic Ocean. Model released.

David Fleetham / Nurse shark (Ginglymostoma cirratum) with a school of juvenile jacks and remora, Bahamas.

Alex Mustard / Reef manta (Mobula alfredi) swimming with Remoras (Remora remora). South Ari Atoll, Maldives. Indian Ocean.

Alex Mustard / Remora (Remora remora) schooling beneath dive boat on a coral reef. North Male Atoll, Maldives. Indian Ocean.

Doug Perrine / Humpback whale (Megaptera novaeangliae) mother supporting her calf at the water surface, Vava'u, Kingdom of Tonga, South Pacific. September. Both mother and baby have remora fish attached to their und...

Doug Perrine / Humpback whale (Megaptera novaeangliae) mother supporting her calf at the water surface, Vava'u, Kingdom of Tonga, South Pacific. September. Both mother and baby have remora fish attached to their und...

Frederique Olivier / Close-up of a Whale shark (Rhincodon typus) swimming near the surface, with Remora (Echeneis), Ningaloo Reef, Western Australia, 2014.

Claudio Contreras / Giant Manta Ray (Manta birostris), with Remoras (Echeneididae) Socorro Island, Revillagigedo Archipelago Biosphere Reserve (Socorro Islands), Pacific Ocean, Western Mexico, March