Revision of the Middle-Eastern dwarf-snakes commonly assigned to Eirenis coronella (Colubridae)

Abstract

The systematics of the Middle-Eastern dwarf-snake Eirenis coronella has caused confusion in the past, but since 1978 this name has been used for a small dwarf-snake with 15 dorsal scale rows, dorsally coloured beige with dark transverse bands. Its distribution: Sinai in the west to southwestern Iran in the east; southern Turkey in the north to Saudi Arabia in the south. Two juveniles from Jordan in the Herpetology Collection of the Hebrew University of Jerusalem, having a distinct “crown” on the head and a dark ventral stripe, stimulated the question whether E. coronella may comprise more than one taxon. To answer this question, we examined snakes from the whole distribution area (n = 110) and analysed the results for males and females separately by principal coordinate analysis (PCO). In both sexes the PCO divided the snakes into two main groups, given species status: 1–Eirenis coronella, comprising all specimens from Sinai, Israel and western Saudi Arabia, and some from Jordan, Iraq and Syria. The Sinai population was given subspecies status, based on differences in scale counts and body proportions. The Western Saudi Arabia population kept its sub-species status, based on its colour pattern. 2–E. coronelloides, distinguished from E. coronella by dark crown, ventral stripe or both; and comprising all specimens from Turkey and the remaining specimens from Jordan, Iraq and Syria. A scatter-diagram of ventrals against sub-caudals separates the taxa almost diagnostically. While E. coronella occupy the northern extremes of the Arabian desert, the range of E. coronelloides is more northern and follows the “Fertile Crescent”.