Physical Characteristics of the Boa Constrictor

The boa constrictor (scientific name Boa constrictor) is a common species of pet snake that can live to be 20 to 30 years old. They are native to Mexico, Central America and South America. Several physical characteristics help to differentiate this species of boa from others.

  1. Size

    • Boa constrictors are an average size snake when it comes to length; they do not reach the massive size that other snakes such as the Burmese python are known for. Just 20 inches long at birth, adults reach lengths of up to 13 feet. Most adult boa constrictors, however, are about 8 feet in length.

    Heat Sensing

    • Other snakes in the Boidae family have obvious heat-sensing pits on their heads used to find warm-blooded prey. The lack of these pits is why the boa constrictor has been placed into its own genus. Instead, less obvious heat-sensing scales sit atop their head.

    Teeth, Lungs and Lost Legs

    • Boa constrictors have what are called aglyphous teeth; meaning they do not have fangs that carry venom. All of their teeth are similar in size and point towards the back of the mouth. Boas make up for their lack of fangs and venom by constricting and suffocating their prey. Although not visible, a unique internal feature worth mentioning are the two equally sized functioning lungs. Most snakes have only one developed lung due to their elongated body. Another interesting feature is the pelvic spurs located on each side of the vent. These are the evolutionary remnants of what once were hind legs.

    Markings

    • The markings of the boa constrictor are what make them truly distinct from other snakes. Overall their back is a blend of shades of brown with a yellowish-white belly. The upper body is a light shade of brown marked with darker ̶0;saddles̶1; along the length of the body. This produces a pattern of large light brown creamy circles along the back as well, alternating with the saddles.

      Within the darker saddle markings are yellowish oblong marks that stand out against the dark brown. Small dark and light dots are found sporadically along the back.

      When viewing the snake̵7;s head from above several obvious markings can be seen. The longest is a stripe running from the nose to the back of the head. Triangle-shaped markings are located from the nose to the eye and behind the eye down to the jaw. The upper lip has a dark half circle. Variations on these markings are seen within the nine subspecies of boa constrictor. Many will have more reddish colors towards the tail giving rise to the common pet trade name of red-tailed boa.