Mexican Blackbelly Garter Snake
Thamnophis melanogaster
A semi-aquatic garter snake from the Mexican Plateau notable for its dark, often solid black underside.
- Venomous?
- Mildly venomous
- Adult length
- 0.5-0.9 m (1.6-3 ft)
- Range
- Central Mexican highlands
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Overview
The Mexican blackbelly garter snake inhabits lakes, marshes, and streams across the central Mexican highlands, including the Valley of Mexico region. It is one of several closely related aquatic garter snakes endemic to Mexico's interior plateau.
Populations have declined in parts of its range due to wetland habitat loss and pollution around Mexico City and other urbanized basins.
How to identify it
- Olive, gray, or brownish dorsal ground color with faint stripes
- Distinctive solid black or heavily dark-mottled belly, giving the species its name
- Keeled scales typical of garter snakes
- Round pupils and a slender build
- Separated from similar Thamnophis by the strongly darkened venter
Habitat & range
Found around lakes, ponds, marshes, and slow streams on the Mexican Plateau, typically at moderate to high elevations. Strongly tied to aquatic and semi-aquatic habitats.
Behavior, diet & reproduction
Active by day, foraging in and near water for fish, tadpoles, and amphibians. Mild venom in the saliva aids in subduing small prey but is not medically significant to humans. Gives birth to live young.
Frequently asked questions
What makes this species distinctive?
Its notably dark or solid black belly, contrasting with the more olive or brown dorsal coloring.
Where does it live?
It inhabits lakes, marshes, and streams across the central Mexican highlands.
Is it dangerous to people?
No, its mild venom is used for subduing small prey and poses no meaningful threat to humans.
What does it eat?
Mostly fish, tadpoles, and other aquatic prey.
Mexican Blackbelly Garter Snake guides
In-depth guides for identifying and understanding Mexican Blackbelly Garter Snake.
