Japan is the main nesting ground for loggerhead turtles in the Northern Pacific. Egg laying takes place from Honshu down to the Ryukyu Islands, and is centered on Yakushima Island. The number of egg-laying loggerhead turtles has declined since 1990. They are threatened with extinction, and are therefore listed as an endangered species on the red list of the IUCN (International Union for Conservation of Nature).
Since 1994, the staff at Okinawa Churaumi Aquarium, have studied the reproduction and physiological ecology of loggerhead turtles through captive breeding, with the goal of conservation.
Discovering the age of sexual maturation in sea turtles is extremely difficult, and the most effective method is through captive breeding. At our facility, we are rearing a female loggerhead turtle that was born at the aquarium in 1995. Each year we conduct an ultrasound scan of her ovaries, and measure the length of her carapace. The results showed that a reared loggerhead turtle’s sextual maturation begins at around 18 – 22 years old. These results, including the successful breeding of a third successive generation of loggerhead turtle were published in the Herpetological Review, a journal published by the American Society for the Study of Amphibians and Reptiles.

Author

Shingo Fukada, Isao Kawazu, Ken Maeda, Takahiro Kobuchi, Masae Makabe, Masakatsu Kino, Konomi Maeda, Mariko Omata, Takahide Sasai( In bold: Foundation staff )

Title

Breeding Success of a Captive F2 Generation of Loggerhead Sea Turtle in Okinawa Churaumi Aquarium

Journal

Herpetological Review