Sea Turtles of Okinawa

© Hazel Cruzado

Sea Turtle Identification


Okinawa sea turtles - sea turtle ID

Green Sea Turtle

The green sea turtle is the most common species in Okinawa, they have a small head, with 4 lateral scutes and 5 central scutes that are of similar size, usually shiny with sunburst patterns, and they have 1 pair of prefrontal scales.

Okinawa sea turtles - sea turtle ID

4 lateral scutes & 5 central scutes

Okinawa sea turtles - sea turtle ID

Sunburst / radiating pattern on scutes on carapace

Okinawa sea turtles - sea turtle ID

The lateral scutes of the carapace are nearly the same size as the central scutes.

Okinawa sea turtles - sea turtle ID

One pair prefrontal scales (scales between eyes)

Okinawa sea turtles - sea turtle ID

Small head & round eyes

green-mouth

Rounded mouth area

green-dorsal-skull

Dorsal Skull

green-ventral-skull

Ventral Skull

green-lateral-skull

Lateral Skull

green-rhampotheca

Mouth: Greens sea turtles have a beak with finely serrated edges, like the teeth of a saw, which enable them to tear seagrasses and scrape algae off of hard surfaces.

Okinawa sea turtles - sea turtle ID

Flipper: One claw on front flipper

Okinawa sea turtles - sea turtle ID

As hatchlings Green Sea Turtles are omnivores, but as adults they are herbivores, similar to many other reptiles. Adult diet consists primarily of algae, seagrasses, and seaweed. They have a finely serrated (sawlike) beak that allows them to scrape algae off rocks and tear grasses and seaweeds.


loggerhead

Loggerhead Sea Turtle

The loggerhead sea turtle comes to Japan only to nest, so they are not as commonly seen as green sea turtles. They have a big head, with 5 lateral and 5 central scutes, and often have barnacles adhered to their carapace.

loggerhead-scutes

5 lateral scutes

5 central scutes

Reddish brown carapace, often with barnacles adhere onto it

More than one pair prefrontal scales

loggerhead-head

Big, fat head

loggerhead-dorsal-skull

Dorsal Skull

loggerhead-ventral-skull

Ventral Skull

loggerhead-mouth

Mouth: Loggerhead Sea Turtles have strong, big jaws that enable them to crush hard-shelled prey like conchs and whelks.

Flippers: Two claws on front flipper

Adult Loggerhead Sea Turtles are carnivorous, eating crabs, conchs, whelks, and horseshoe crabs. Hatchlings are omnivorous, eating both plant and animal material. They have a massive head and strong jaws which enable them to crush hard-shelled prey.


Hawksbill Sea Turtle

Hawksbill sea turtles are encountered every once in a while in Okinawa, more often on the smaller islands like Zamami. The central scutes are imbricated (overlapped) and the beak is “hooked”

4 lateral scutes

5 central scutes

hawksbill-scutes

Central scutes on carapace overlapping

hawksbill-serration

The rear edge of the carapace is deeply serrated.

Thick carapace scutes, with streaks of brown and black on an amber background

Two pairs of prefrontal scales

hawksbill-beak

Small, narrow head that tapers to a distinct hooked beak

Dorsal Skull

Ventral Skull

Often referred to as spongivores because of their specialized diet which consists almost exclusively of sponges. The hawksbill has a sharp, narrow “bird-like” beak that allows them to reach within crevices on the reef.