PREDATION HABIT OF TRIONYX SINENSIS ON JUVENILE MISGURNUS ANGUILLICAUDATUS
YUAN Xiang-Yang;ZOU Li-Chang;SHENTU Yan;ZHU Wei-Dong;WANG Zhi-Zheng;Zhejiang Ocean University;Fishery Technology Extension Center of Yuyao;
A method concerning was used to study the predatory efficiencies of Trionyx sinensis(the Chinese softshell turtle) juvenile Misgurnus anguillicaudatus(the pond loach, dojo loach), we studied the predation-pray relationship in two groups in snout-vent length at A [(37.53±7.72)mm] and B [(63.13±12.95)mm] of the juveniles cultured in indoor cement tanks(6m×4m×1.2m). The results show that:(1) The hunting time of T. sinensis concentrated in 00:00 to 4:00, and its preferential predation on M. anguillicaudatus in group A has no relationship to the initial proportion of the juveniles from A and B groups.(2) The type of predatory functional response of T. sinensis to M. anguillicaudatus is of Holling-Ⅱ model, and the theoretical maximal preying quantity were 16.13(Group A) and 9.06 ind(Group B).(3) The intraspecific interference and interspecific interference models could be expressed in exponential equations for each group case to describe statistically the relationships between turtle and fish of different groups, involving parameters of the number of fish initially fed, number of the fish preyed during the experiment, and number of the turtle farmed. These models or equations can be used to determine best economic practice and provide guidance for the maximum profit to favor turtle farmers.