The Black Sea Turtle

The Black Sea Turtle is found primarily in coastal waters, bays and estuaries in tropical and subtropical latitudes. In the eastern Pacific Ocean from southern California, USA to Chile, west to the Galapagos Islands, Hawaii and Papua New Guinea. The primary nesting beaches of Mexico include: Colola, Maruata, Mexiquillo, Chimapa, and Motin de Oro.
This turtle's common name is derived from the almost black coloration of it's shell. The upper shell (carapace) is dramatically tear-drop shaped and steep sided. The narrow part of the teardrop is toward the tail end of the turtle. The lower shell (plastron) is generally dark gray or gray-green. At one time, the black turtle was considered to be a race of the green sea turtle. Some experts continue to list it as such. Like green sea turtles, this species has a single pair of enlarged prefrontal scales on the head. The head size is comparatively smaller than that of green sea turtles. There are four costal scutes on the carapace. Adult black turtles weigh as much as 220 pounds (100 kg) and measure up to 39 inches (1 meter) in carapace length.

Present population estimates vary from 5,000 to 10,000 individuals. This turtle feeds primarily on marine algae.
Males and females mature between 16 and 25 years. The breeding season depends on the latitude. Internal fertilization takes place when the male and female copulate. This is the only time there is vocalization. Like many species, there is male competition. One male may try to bite another male who is copulating with a female. Mating occurs underwater or on the surface about one kilometer from the shore. Sometimes the female will retain enough sperm to nest several times that year. Nesting occurs every three to six years. When the female is ready to lay her eggs, she leaves the water, crawls onto the sand and starts digging for hour and hours until her flippers will not allow her to dig deeper. Likewise other sea turtles, this happens at night. She then lays approximately 70 eggs. This group of eggs is called a clutch. She covers them with sand to protect them from the sun, heat, and predators. The average female produces 2.5 nests per season. Renesting intervals range from 9-17 days. The eggs typically incubate from 50 to 55 days prior to hatching.