Alex Mustard / Suwanee freshwater turtle (Pseudemys concinna suwanniensis) swimming beneath trees in a freshwater spring. Devil Spring, Ginnie Springs, High Springs, Florida, USA

Pete Oxford / American alligator (Alligator mississippiensis) half submerged, Okefenokee National Wildlife Refuge, Florida, USA

John Cancalosi / Snapping turtles (Chelydra serpentina) with Red-eared sliders (Pseudemys rubriventris) and River cooter (Pseudemys concinna) and Bluegills (Lepomis macrochirus), Maryland, USA, June.

Alex Mustard / Portrait of a Suwanee cooter (Pseudemys concinna suwanniensis) in a freshwater spring. Gilchrist Blue Springs State Park, High Springs, Florida, USA

Alex Mustard / Portrait of a Suwanee cooter (Pseudemys concinna suwanniensis) in a freshwater spring. Gilchrist Blue Springs State Park, High Springs, Florida, USA

Alex Mustard / Suwanee freshwater turtle (Pseudemys concinna suwanniensis) swimming beneath trees in a freshwater spring. Devil Spring, Ginnie Springs, High Springs, Florida, USA

Alex Mustard / Suwanee freshwater turtle (Pseudemys concinna suwanniensis) swimming beneath trees in a freshwater spring. Devil Spring, Ginnie Springs, High Springs, Florida, USA

Michel Roggo / Striped mullet (Mugil cephalus) at boundary of clear water of Fanning Springs and red water of the Suwannee River, Fanning Springs State Park, Florida, USA. March 2011. Photographed for The Freshwater...

Roger Powell / American black vulture (Coragyps atratus) perched in a tree, Lower Suwannee, Levy County, Florida, USA, April

Roger Powell / North American river otters (Lontra canadensis) family group with one of which has just caught a crab, Lower Suwannee River, Levy County, Florida, USA April

Tim Fitzharris / Oak (Quercus sp) trees along river, Suwannee River, Suwannee River State Park, Florida

John Cancalosi / Eastern river cooter (Pseudemys concinna concinna) Louisiana, USA, July.