Common Basilisk

The common basilisk can be distinguished from similar species within its range by its large size and the high fin-like crest along its back. Most common basilisks are brown and cream in color. Males also have high crests on the head and tail. Both genders are brown to olive, and have a white, cream, or yellow stripe on the upper lip and a second stripe along either side of the body; these stripes have higher contrast in juveniles and fade as the lizards age. Hatchlings weigh a mere 2 grams (0.071 oz) and are 38 to 43 mm (1.5 to 1.7 in) long. Adults can grow to a total length (including tail) of 76 cm (2.5 feet). Females are generally 135 to 194 g (4.8 to 6.8 oz), and weigh half as much as males. The tail comprises 70 to 75% of the total length: for example, a 70-cm-long (27.5-inch-long) common basilisk would have a 50-cm-long (19.5-inch-long) tail. The common basilisk has a large mouth with saw-like teeth on the inner sides of the jaw. While the common basilisk is most known for its ability to run on water, it is also an excellent climber and swimmer, and has been known to stay underwater for up to half an hour. The average lifespan is seven years in captivity; in the wild, it tends to be less because of predators. When startled, the common basilisk escapes by speeding to the nearest edge of water—and continues sprinting. …

The common basilisk is found in tropical rainforests throughout Central America and in northwestern South America, usually living in low elevations, from sea level to 600 m (2,000 ft). In Costa Rica, this basilisk can be found as high as 1,200 m (3,900 ft) in some places. The species ranges from southwestern Nicaragua to northwestern Colombia on the Pacific side, and from central Panama to northwestern Venezuela on the Atlantic side. In Costa Rica, it is mostly found on the Pacific side of the country. The equivalent species on the Atlantic side is the green basilisk (Basiliscus plumifrons), which occupies similar habitats and has similar biology.

B. basiliscus is an omnivore; its diet consists of insects, for example, beetles or dragonflies; flowers, and small vertebrates such as snakes, birds, eggs, and fish.

The common basilisk is named for the creature of Greek mythology made up of parts of a rooster, snake, and lion which could turn a man to stone by its gaze: the basilisk. Its generic, specific, and common names all derive from the Greek basilískos (βασιλίσκος), meaning 'little king'. The specific epithet was given in Carl Linnæus' 10th edition of Systema Naturæ.