Captive breeding of the Siamese narrow-headed softshell turtle Chitra chitra Nutphand, 1986 (Testudines: Trionychidae)

摘要

A captive breeding program of a critically endangered species, the Siamese narrow-headed softshell turtle Chitra chitra Nutphand, 1986, was conducted in two 400 m~2 ponds at Kanchanaburi Inland Fisheries Development Center (KIFDC), Kanchanaburi Province, Thailand from 2000 to 2002. Copulations were observed during September to February. Two females laid eggs during February to April in artificial sandbanks. Each captive female produced 3 or 4 clutches/year with 40-88 eggs/ clutch. Egg sizes (n=220)were 31.94 +- 1.57 mm in width (range 26.89-34.37 mm), 33.16 +- 1.54 mm in length (range 29.39-40.49 mm) and 19.00 +- 1.67 g in weight (range 15.31-21.60 g). The mean incubation time of C. chitra eggs was 59 +- 3 days (n = 255) with a range of 55-65 days at 24-42 deg C air temperature and 24-39 deg C sand temperature. Hatchling sizes (n=297) were 38.46 +- 1.52 mm in carapace width (range 32.00-4l.67 mm), 42.97 +- 1.59 mm in carapace length (range 36.27-46.66 mm) and 13.10 +- 1.03 g in weight (range 9.09-14.89 g). The hatching success in each clutch varied from 3 to 94 percent. The hatchlings were fed with fry fishes of Labeo rohita and Oreochromis niloticus. After 14 weeks, mean hatchling size was 86.70 +- 5.17 mm carapace width, 91.72 +- 5.75 mm carapace length and 103.97 +- 18.08 g weight, respectively. The survival rate of juveniles was 90.64 percent.