Geographic variation in Echis coloratus (Viperidae, Ophidia) in the Levant with the description of a new subspecies

Abstract

Geographic variation of morphological characters was studied in the Levantine populations of the Echis coloratus complex. Multivariate analyses of morphological characters showed that within the Levant the northern and southern populations differ in overall morphology. The exact nature of the contact zone between the two groups is unclear. The difference between the two populations may be the result of separate phylogenetic history or of different selective regimes of two ecologically different biogeographic regions. The samples from the southern Levant and from continental Egypt resemble that from the type locality of E. coloratus s.l., therefore these populations are assigned to the typical subspecies Echis coloratus coloratus. The northern Levantine population is recognized at the subspecies level on the basis of its phenetic difference from the southern Levantine population. The new subspecies Echis coloratus terraesanctae n. ssp. differs from the parapatric E. coloratus coloratus in its lower ventral count and higher number of dorsal scale rows on all sections of the body, in its relatively larger eyes and in colour pattern. It occurs in the central and northern Dead Sea basin, the Jordan Valley and their western slopes East of the watershead. From the southern Dead Sea basin it penetrates the Negev, where it probably composes a hybrid swarm with E. c. coloratus. The study of its distribution in Jordan needs further effort.