1Ishigaki Tropical Station, Seikai National Fisheries Research Institute, Fisheries Research Agency, Ishigaki, Okinawa 907-0451, 2Graduate School of Science and Technology, Nagasaki University, Bunkyo, Nagasaki 852-8521, 3National Research Institute of Aquaculture, Fisheries Research Agency, Minami-ise, Mie 516-0193, 4Institute for East China Sea Research, Nagasaki University, Bunkyo, Nagasaki 851-2213, 5National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Hatsukaichi, Hiroshima 739-0452, Japan
In order to reveal the reproductive ecology of captive hawksbill caught from the wild, we investigated the mating and nesting behavior, clutch size, number of clutches and hatching rate from 2006 to 2009. We used a video camera system in order to determine the date and time of mating and nesting. Mean mating duration ranged from 50 to 150 minutes, and the period from mating to the 1st nesting was 29.6±3.4 days. As for nesting, 4 females nested a total of 16 times between 2006 and 2009. Mean clutch size and number of clutches were 135.9±25.2 eggs and 3.5±0.7 clutches, respectively. These results closely correlated with data from wild populations. Hatching rate of captive eggs was markedly lower compared to that of wild eggs. However, the straight carapace length and body weight of hatchlings in captivity were comparable to those of the wild ones.