Trading System, Demographic Parameters of Harvested Population and Habitat Characteristics of Asian soft-shell turtle (Amyda cartilaginea Boddaert, 1770) in Jambi Province

Abstract

Asian soft-shell turtle (Amyda cartilaginea Boddaert, 1770) has been recorded as the most harvested turtle species in Indonesia, mainly for consumption purpose in oriental countries. In order to prevent over-exploitation and the declining of the population, harvesting has been limited by quota. In practice, the harvesting still showed an enormous number and the determination of the quota itself was not yet based on the data of Amyda population. This research was aimed to identify mortality rate through identification of the trading system since for highly-valued species harvesting was the major cause of mortality. The demographyc and morphometric parameters were measured to characterize the harvested population by its size, sex ratio, age-class and range of bodymass and carapace length. Twenty dissected speciments were observed to study the reproduction condition of different size of Amyda, thus used to estimate potential lost caused by harvesting. Amyda’s habitat was characterized by measuring 9 biophysical variables of each of 90 fishing plots in 16 rivers and 3 lakes. The result showed that the size of harvested population of Amyda at the trader level was different from one to another, but showed similar trends of domination in sex and age class which were adult females and reaching the number of 58.28%. The people dealing with the harvesting activities of Amyda had no preference for size and sex of the harvested animal. Reproduction condition of the observed Amyda showed that at the size of five kilograms, the females were at the age of maturity. Kolmogorov-Smirnov test on the habitat biophysical variable on stream showed that Amyda had no habitat preference.