Delma excitable

The excitable delma looks remarkably like a snake, because through evolution, the species has completely lost its limbs. It has an extremely long and slender body with a tail that is three to four times its body length. The excitable delma's snout is also rounded in shape.

The body size from snout to vent in an adult excitable delma is about 80 to 90 mm, with a tail that extends 240 mm. Juveniles' measurements are typically 40 mm for the body and 136 mm for the tail. They are small to moderate in size compared to the rest of the Delma genus. The body of the excitable delma is an olive green to grey-brown colour with a white cream underbody, and consists of 14 rows of midbody scales, three subocular supralabial scales, and one pair of supranasal scales. It has three distinct black markings across the upper section of the head and neck. The black markings are intersected by four yellow bands, the first band on the muzzle, the second before the eye, the third behind the eye, and the final across the back part of the head. The markings on the excitable delma's head and neck are more dominant on the juveniles.

The excitable delma gets its name because it is the most active species in the pygopodids. It has a unique jumping defense mechanism in which its body twists in a display of acrobatics to scare or confuse predators. When the excitable delma is agitated, it uses its long tail to generate an upward thrust, which causes its entire body to lift from the ground. When the delma leaps it erratically changes its direction with each jump. The University of California, Berkeley observed an adult excitable delma in captivity; without any stimulus, the delma was filmed jumping more than 30 times. The jumps reached heights of 11 to 15 cm and lasted 0.41 to 0.45 seconds from initial lift to impact. The excitable delma moves through the different ecosystems it inhabits in a locomotor motion known as saltation. Saltation is common in limbless vertebrates, and in the pygopodids family is a behavioral response to predation. It can be sometimes be confused as an escape response, but this is not the function of this behaviour. Saltation is the locomotion motion of side-pushing, and the jumping in delmas allows them to move their bodies at a greater wave-speed. …