Main differences between Vipera seoanei seoanei and Vipera seoanei cantabrica
1- Colouration: The
cantabrica subspecies has an unmistakable pattern; a zigzag consisting of dark crossbars over a grey ground colour. The rest of the colour forms belong to the nominate race
Vipera seoanei seoanei, with the exception of the melanic specimens, which can be found in both subspecies.
Vipera seoanei seoanei - photo: Edgar Wefer
Vipera seoanei cantabrica - photo: Daniel Gómez
2- Head: The frontal and parietal scales are usually present in
Vipera seoanei seoanei, while in
Vipera seoanei cantabrica they are often fragmented.
3- Venom: The
Vipera seoanei cantabrica venom is at least twice as toxic as that of
Vipera seoanei seoanei.
4- Pholidosis: The
cantabrica subspecies has a higher number of ventral and subcaudal scales.
Vipera seoanei seoanei has only one row of scales between the eye and the supralabials while
Vipera seoanei cantabrica has one and a half or two.
5- Labials: Vipera seoanei seoanei normally exhibits pigmentation on most of the supralabials while it is quite common for
Vipera seoanei cantabrica specimens to have no pigmentation at all on the supralabials.