Solenoglyphous. The maxilla has two sockets, where hollow and replacement
fangs are fitted with highly modified,
movable skull bones allowing for
operative movement of the hollow long recurved anteriorly-positioned fangs.
Broad triangular heads covered by
small scales, juxtaposed or imbricate, which are located high and oblique in
the head. Nostrils point upwards.
Elliptical pupil in the eye; 31-35 rows of keeled dorsal scales at midbody, those on flanks are slanted ventral and
their keels are serrated. Ventrals broad (Gasperreti,
1988). Tail is very
short with either paired or entire subcaudal scales. Dorsal scales are keeled
at various levels, and the ventral scales are wide and broad.
Recent molecular studies
on this family in the Middle and Near East revealed new aspects of taxonomic
treatment for many species (Herrmann et al.,
1992; Lenk
et al., 2001; Stümpel & Joger, 2009). In Jordan,
this family is represented by the subfamily Viperinae, and includes five genera
(Cerastes, Daboia, Echis, Macrovipera,
and Pseudocerastes).
Figure (3) Cerastes gasperettii gasperettii Leviton & Anderson,
1967
Common name: Desert Sand Viper, Arabian Horned Viper.
Diagnosis. Head
triangular and broad, wide flattened and clearly distinct from neck: head
covered with small irregular tubercularly keeled scales. C. g. gasperettii is characterized by a thick body and short tail. Pupil
elliptical. Eyes separated from labials by rows of small scale; absence of the cluster of enlarged scales at
midocciptal region of head between the
eyes. A pair of superocular horn-like spiny scales above the eye can be either present or absent. If horns are present
they point externally; four to five superalabials scale rows, the first
supralabial relatively small. Upper labials,
12-15. Lower labials, 13-15. Number of scales in ocular ring, 12-14. More than
four to five rows of scales between the eyes. Dorsal scales heavily
keeled with apical pits. Lateral scales are smaller laterally keeled serrated and arranged in an oblique series. Scale rows
at midbody, 31-35; ventrals, 152164;
subcaudals divided and vary from 33-37. Anal scale undivided. The Sand
Horned Viper exhibits sexual dimorphism as follows: head of males larger
including length, depth and width; higher number of subcaudal and fewer dorsal
scale rows; longer tail length and fewer ventrals (over
153 in males and more than 155 in females) and wider eye
diameter.
Maximum length 85 cm (most specimens are about half
that size). Females grow larger than males. Colouration: The
colour varies regionally and can be reddish, yellowish or grey, depending upon
the actual colour of the sand where a population lives. The pattern consists of
indistinct brown spots in four to six longitudinal series, a dark streak on the
tail and a variable head pattern. The head pattern is accentuated in
some populations of C. g. gasperettii, in which case the dark band
between the eye and the angle of mouth is accompanied dorsally by a light band.
Habitats and ecology. The Arabian Horned Viper is a true psamophile
species. It was seen and collected from
sand dunes in Wadi Ramm and Al Hazim. Also, they inhabit sandy soil where vegetation or
rocky outcrops provide shelters. In Al Hazīm, the area is dominated by Haloxylon
persicum and Nitraria retusa.
It is adapted to these habitats through its morphology, physiology
and behavior. During the daytime it
hides in rodent borrows, and specimens have been seen buried in the sand
with eyes protruding from the ground surface. It
starts its activity after sunset and is active at night, moving across
the sand searching for food, especially
rodents. Side-winding trails are very
characteristic for this viper. It was collected near roads in Wadi
Ramm (Amr and Disi, 2011).
