شناسايي سيستماتيكي د وگونه مار آبي Natrix natrix و مار چليپر Natrix tessellata بر اساس تحليل هاي چند متغيره

Systematic identification of Natrix natrix and Natrix tessellata based on multivariate analysis

Two species of genus Natrix (N. natrix and N. tessellata) have been reported from Iran. Monothetic method of identification and diagnostic characters of dichotomous keys can not distinguish this two species exactly. In this research, we examined the ability of polythetic method and multivariate analysis for identification of this two Iranian species. Four morphologic, two morphometric and 14 meristic characters have been studied in 41 specimens (collected during 1997 to 2005 and deposited in Zoological Museum of Gorgan University) from different part of Iran. Statistically significant difference exists between this two species in number of preocular scales, number of postocular scales, number of sircumorbital scales, number of subventrals and number of subcaudals (p<0.01). The specimens of N. natrix and N. tessellata have been actually separated based on coordinate I (72% variances and eigenvalue 1.7) and coordinate II (15% variances and eigenvalue 0.3) in principle coordinate analysis. In discrimination analysis, all of specimens were assigned to their correct apriori group (species), based on three first functions. The most important characters were: Number of preocular scales, number of subventrals, number of subcaudals and body length. Results showed that multivariate analysis can identify the specimens of N. natrix and N. tessellata.