Fer-de-lance

Description:

Bothrops species can be distinguished by their broad, flattened heads which are set apart from the rest of the body. To prevent water loss where they occur in drier regions, this species has more scales. Across its geographic range, this species varies greatly phenotypically. As a result, great confusion between it and other related species, most notably Bothrops atrox, which is similar in color but usually has yellow or rust like tones and rectangular or trapezoidal blotches. The head of this snake is light to dark brown or even black. Although usually absent, it may have occipital botches or streaks that range from indistinct to distinct. The underside is most often pale yellow. Specimens of this species may weigh up to 6 kilograms (13 lb) and are often 1.2 to 1.8 meters (3.9 to 5.9 ft) in length. Very big females can reach lengths up to 2.5 metres (8.2 ft), although this is uncommon.[8][2] This species has different patterns and colors on its dorsal and ventral sides and it exhibits a post-orbital stripe. The ventral side is yellow, cream, or a whitish gray, with dark blotches that are more frequent closer to the posterior end. Ventrolaterally, B. asper has interchanging gray scales which are more pale towards the medial line. There is a great variety of colours on its dorsal side: olive, gray, light brown to dark brown, tan or sometimes nearly black. Dark triangles with pale edges can be seen laterally, which range in number from 18 to 25. Apices either alternate or are reflective of each other over the middorsal line. In the interspaces, there are dark, paravertebral blotches. Specimens may have a yellow zig-zag shaped line on each side of the body.[2] These are among the most sexually dimorphic of all snakes. The two sexes are born the same size, but by age 7 to 12 months, females begin to grow at a much faster rate than males. As already stated, adults are typically 1.2 to 1.8 meters (3.9 to 5.9 ft) in length. From birth, males are notably smaller in size than females. Females have thick, heavy bodies and grow significantly larger than males.[2] They also have heads two or three times as big as males relative to their size and proportionally bigger fangs (typically 2.5 cm) as well.

Habitat:

This species likes moist environments, and occurs in most life zones located at low or middle elevations (up to 600 metres (2,000 ft)), excluding those with strong seasonal dry periods. They are, however, sometimes found at much higher elevations. This is true in the premontane forest in Costa Rica, the cloud forest of Guatemala and Mexico, or the lower montane wet forest in the Caribbean Region of Colombia and Ecuador. It chiefly inhabits tropical rainforest and evergreen forest, but it also occurs in drier areas of tropical deciduous forest, thorn forest and pine savannah near lakes, rivers and streams. The home range of B. asper averages between 3.71 ha and 5.95 ha, which is comparatively small in relation to other pitvipers.[