Reptiles are a class of vertebrates that include snakes, turtles, crocodilians, and lizards. Most reptiles have a key set of characteristics that separate them from other vertebrates. Typically, reptiles are oviparous, meaning they lay eggs as opposed to giving birth to live young. Reptiles are also ectothermic, meaning they cannot self-regulate their body temperatures and instead rely on the external environment. All reptiles breathe air with lungs. The last key feature of reptiles is their bodies are covered by either scales or scutes. Crocodilians and turtles have scutes, while snakes and lizards have scales. Marine reptiles have to be specially adapted to survive in their specific environments.

Sea turtles are a well-known marine reptile. There are seven living sea turtle species worldwide: the green (Chelonia mydas), loggerhead (Caretta caretta), Kemp’s ridley (Lepidochelys kempii), hawksbill (Eretmochelys imbricata), leatherback (Dermochelys coriacea), flatback (Natator depressus), and olive ridley (Lepidochelys olivacea). The first five can be found in the waters around Florida, and nest on Florida beaches. Sea turtles have true flippers, as opposed to their freshwater counterparts who have webbed feet. No species of sea turtle is able to retract in their shells. This is because sea turtles need to be hydrodynamic, and having openings along a shell hinders that ability.

Sea snakes are a group of venomous snakes that live in marine habitats for most of or all of their lives. Most species of sea snakes cannot survive out of water, as they are unable to move on land. Sea snakes have a body shape that resembles an eel, and also have a paddle-like tail. These adaptations make them adept swimmers. Sea snakes are usually three to four feet in length, but one species, the yellow sea snake (Hydrophis spiralis) can reach up to ten feet in length. Sea snakes are found primarily in the Indian and Pacific oceans.

Marine iguanas are an iguana species found in the Galapagos Islands in Ecuador. They live on the coast, but forage for algae in the ocean. The larger males dive deep to find food, while smaller males and females stick to intertidal zones to find their food. Marine iguanas actually have many symbiotic relationships with other species. Birds and crabs have been observed eating mites off of the iguanas’ skin and fish will clean off their molting skin by eating it when the iguana is underwater.