Abstract:
Ecological and morphological data of green water dragon, Physignathus cocincinus were collected from August 1997 to July 1998. In Thailand, it distributed in central, eastern and northeastern parts and inhabited near the streams or the riverine habitat. It occurred either on a small or medium tree at the average height of 2.27 meter. Teh analysis of microhabitat showed that the juvenile located at the level which was significantly lower than those of the sub-adult and the adult at p<0.05. According to physical environmental factors of P.cocincinus, the average temperature, the relative humidity and the average rainfall were 28 ํC, 74.47% and 160.74 mm/month, respectively. From the study, the temperature in each area of occurrence was not significantly different from one another at p<0.05. Mean comparison of parameters of morphological characters were compared in each age groups. The result showed the differences in 8 characters, e.g. labial length, head depth and tail base length, which significant at p<0.05. In addition, sexual dimorphism was studied by using t-test and simple linear regression analysis in which 8 characters, e.g. head width, forelimb length and height of nuchal crest, were significantly different between sexes at p<0.05. From the data obtained, it revealed the ontogenic change and sexual dimorphism in P.cocincinus. The activity period of P.cocincinus was approximately between 6.00-18.00 hr. The duration of the juvenile daily activity was significantly longer than those of the sub-adult and the adult at p<0.05.