Uchida et al. (2000) AES Abstract

UCHIDA, S.;TODA, M;KAMEI, Y.;TERUYA, H. Okinawa Expo Aquarium, Okinawa, 905-0206 Japan. The husbandry of 16 whale sharks Rhincodon typus, from 1980 to 1998 at the Okinawa expo aquarium From 1980 to 1998 16 whale sharks, Rhincodon typus , were kept in captivity at Okinawa Expo Aquarium, Okinawa, Japan. They were captured around Okinawa Is. by set-nets the center of which is located at 26¡23«N, 127¡41«E from March to September. The sea water temperature of the time captured were 21.1 to 29.0¡C at the depth of 20 m. Only two of 16 sharks were females and 14 were males, The mean value and range in total length and body mass were 4.8 m and 3.1 to 6.3 m, and 814 kg and 290 to 1750 kg respectively. They were kept in the Kurosio tank which is 27 m long, 12 m wide and 3.5 m deep 1,100 m3 in volume. Water parameters of the tank in mean and range were as follows : Water temperature (deg C) was 24.6 and 19.8 to 29.6, ph 8.2 and 7.9 to 8.35, and salinity (o/oo) 35.79 and 33.04 to 37.36. Mean and range of survival time in the tank were 502 days and 3 to 2056 days (ca. 5y 8m). The Whale sharks were fed on Euphausia pacifica, E. superba, Sergia lucens, Loligo japonica and Spratelloides gracilis once a day 6 days week. Mean feeding rates (food quantity / body mass / week x 100) of a 3.65 m female were 11.0 % in the first year of keeping, 8.5 % in the second year and 8.0 % in the third year. Mean growth per year of this shark was 29.5 cm in total length ( survival time : 2056 days) , 4.5 m male shark 21.6 cm (1040 days) and 4.85 m male 25.5 cm (458 days) respectively. Feeding and other behaviors in tank are reported.