A work colleague of mine Stuart Trotter found a Yellow-bellied House
Gecko Hemidactylus flaviviridis in
our offices in Dhahran and took the below photo of it. Yellow-bellied House
Gecko occur through parts of the Arabian Peninsula including Saudi Arabia as
well as Afghanistan, Egypt, Ethiopia, India, Iran, Iraq, Nepal, Pakistan and
Somalia and can vary their body colour depending on the time of day, being
greyish, olive or brown, patterned with indistinct bands on the back and
yellowish on the underside. During the day, the gecko is usually much darker in
colour, with contrasting, chevron-shaped bands on the body with the toes having
broad pads and small claws. They are associated with man-made structures such
as houses, but during the day, they retreat to undisturbed crevices and other
such hiding places coming out at night to feed primarily on insects. They can
climb vertical walls and walk on ceilings which is achieved by having
specialised toe pads, which are covered in small scales called ‘scansors’ which
can have up to 150,000 microscopic, highly branched, hair-like structures,
known as setae, which form hundreds of saucer-shaped ‘end plates’. This gives
the Gecko an enormous surface area in relation to its body size, enabling it to
grip all kinds of surfaces. This species of Gecko has particularly large and
sensitive eyes, with pupils which open-wide at night to let in maximum amounts
of light, giving it excellent vision in the dark. The pupils contract to
vertical slits during the day to protect the retina from harsh sunlight, while
the eyelids are fused to form a transparent cover for additional protection.
Any dust or debris in the eye is licked away by the gecko’s extremely mobile
tongue.
