Claudio Contreras / American crocodile (Crocodylus acutus) exhaling bubbles underwater, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico, May.

Claudio Contreras / American crocodile (Crocodylus acutus) split level with animal resting at surface in shallow water over seagrass bed, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Claudio Contreras / American crocodile (Crocodylus acutus) rear view of animal resting in shallow water, close up of tail, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Claudio Contreras / American crocodile (Crocodylus acutus) resting just above seagrass underwater, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Claudio Contreras / American crocodile (Crocodylus acutus) extreme close up with jaws open, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Neil Aldridge / Nile crocodile (Crocodylus niloticus) snatching a Mozambique tilapia (Oreochromis mossambicus) in its jaws, Shingwedzi River, Kruger National Park, South Africa.

Neil Aldridge / Nile crocodile (Crocodylus niloticus) resting in the sun on a grassy island in the middle of the Chobe River, northern Botswana.

Ingo Arndt / American Alligator (Alligator mississippiensis) in water, Everglades National Park, Florida

Claudio Contreras / Morelet's crocodile (Crocodylus moreletii) silhouetted in sinkhole, Cenote Carwash, near Tulum, Yucatan Peninsula, Mexico, January

Claudio Contreras / Morelet's crocodile (Crocodylus moreletii) in sinkhole, Cenote Carwash, near Tulum, Yucatan Peninsula, Mexico, January

Claudio Contreras / Morelet's crocodile (Crocodylus moreletii) in sinkhole, Cenote Carwash, near Tulum, Yucatan Peninsula, Mexico, January

Wim van den Heever / Nile crocodile (Crocodylus niloticus) still in the fast flowing water of the Mara River, taken with slow shutter speed. Masai Mara, Kenya.