Details

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Common Name: Jansen's Rat Snake (Black Phase)

• Scientific Name: Gonyosoma jansenii

• Family: Colubridae

• Classification: Reptilia (Squamata)

• Toxicity Level: Non-Toxic

• Origin: Indonesia (Sulawesi)

• Adult Size: 1.8 – 2.4 meters (6 – 8 feet)

• Lifespan: 15 – 20 years

• Diet: Carnivore (Rodents, birds)

Jansen's Rat Snake is the "bodybuilder cousin" of the Red Tailed Racer. While they are born olive-green, this listing specifies the Black Phase (typically adults). These are massive, muscular arboreal snakes that look like velvet-black dragons. They have a keeled belly that helps them climb vertical tree trunks and a distinct laterally compressed body shape.

Notes Comparison: Unlike the Red Tailed Racer (G. oxycephalum), G. jansenii is much heavier, thicker, and grows larger. The Black Phase is particularly sought after for its imposing appearance.
Husbandry: They require very large arboreal cages. They are generally robust feeders on rats.

Why Source This Species:

• Velvet Black Texture: Their scales have a unique matte texture that absorbs light, making the black coloration look incredibly deep and rich.

• Impressive Bulk: They offer the size and presence of a python but with the activity level and handling characteristics of a colubrid.

• Hardy Giant: Once established, they are one of the most robust arboreal snakes available.