Varanus Indicus - Anatomy and Morphology

Anatomy and Morphology

The monitor's body is dark green or black in color and covered with golden yellow spots, with light coloration on the top of the head and a solid, cream colored belly lacking dark markings. It has a distinct dark purple tongue and serrated teeth. The mangrove monitor attains different sizes in different parts of its range, but seldom if ever exceeds 1.5 meters in total length. Australian herpetologist Harold Cogger gives a total length of 100 cm for Australian specimens. The tail is almost two times the length of the body and laterally compressed to aid in swimming. Like the rest of the lizard's body it is covered with small, oval, keeled scales.

This monitor has the ability to increase the size of the mouth by spreading the hyoid apparatus and dropping the lower jaw in order to eat large prey, a process similar in appearance to that of snakes, although the jaw of the mangrove monitor remains rigid. Mangrove monitors possess a Jacobson's organ which they use to detect prey, sticking their tongue out to gather scents and touching it to the opening of the organ when the tongue is retracted.

The mangrove monitor is one of only two species of monitor lizard, the other being Varanus semiremex, that possess salt-excreting nasal glands, which enable them to survive in saltwater conditions and to consume marine prey. The presence of this gland probably enabled the monitors to reach new islands and aid in its dispersal throughout the Pacific.