Boa constrictor imperator

Boa imperator is a nonvenomous boa species of large, heavy-bodied snake that is commonly kept in captivity. Boa imperator is part of the family Boidae and is found in Mexico, Central America and South America west of the Andes Mountains (primarily Colombia). It is commonly called the northern boa, Colombian boa and common northern boa and is frequently and erroneously referred to as the red-tailed boa or Colombian red-tailed boa, especially in the pet trade. Boa imperator is wide-ranging, with animals living in both Central America and northern parts of South America. As a result, the appearance of this snake varies greatly depending on the specific locality. As one of the smaller Boa species, they average between 1.3 and 2.5 m in length when fully grown, but have been known to reach 3.7 m. They usually weigh around 6 kg (13 lb), although females are significantly larger than males. Lifespan in the wild is around 20–30 years, but 40 can be exceeded in captivity. Although Boa imperator exhibits almost identical patterns to Boa constrictor, this species often has a darker tail, usually dark brown or very dark red. They are, however, usually just as colorful as their counterparts and, like the larger boas, can be bred into a variety of different colors, given the right conditions to breed. One population is found on the Cayos Cochinos (Hog Islands) off the northern shore of Honduras. These are naturally hypomelanistic, which means that they have reduced melanin, thus are more lightly colored, although they retain the distinctive darker tail that is characteristic of most members of this species. The color of the tail may vary from salmon-pink to orange. Another well known population of Boa imperator is the population from Nicaragua. While not as small as the dwarf insular island populations, adults are still smaller than the larger B. c. constrictor. The size of a mature female Nicaraguan boa is 1.1 m and 1.9 kg, while the larger female B. c. constrictor is not mature until she reaches 1.6 m and 4.5 kg. Nicaraguan individuals typically have a compact saddle pattern on their backs that is often circular in shape. These boas have a reputation for being 'nippy', with some individuals being quick to bite in self-defense. Mainland specimens from Colombia can be among the larger boas, but this subspecies also includes a number of dwarf insular populations, such as those from various Caribbean islands and the Sonoran Desert of Mexico. These populations represent the smallest members of the species. Boa imperator has 55-79 dorsal scales, 225-253 ventral scales, 47-69 subcaudal scales, 18-22 supralabial scales and 1-2 anal scales. Boa imperator is commonly confused with other Boa species, such as Boa constrictor. They can be distinguished by virtue of having fewer dorsal and anal scales.