Long considered to be a subspecies of the green sea turtle (Chelonia mydas), black sea turtles tend to inhabit bays and protected shores and aren’t commonly observed in the open ocean. A black sea turtle’s upper shell (carapace) is steep sided, tear shaped and blackish with brown and yellow mottles. Its lower shell (plastron) is dark gray or gray green. Sea turtles can’t draw their arms, legs and heads into their shells, but their large size and scaly, tough neck skin also help protect them from predators.