Thamnophis sirtalis

A well-ventilated terrestrial terrarium with a large water body (a semi-aquatic species).

Minimum dimensions for one adult; provide more space for large females or a pair. Provide hides on both sides of the thermal gradient, climbing branches/décor (it climbs readily) and a well-secured lid (an excellent escape artist that slips through the smallest gap).

Moderate humidity with good ventilation. Avoid constantly saturated air, which promotes respiratory and skin infections; a slightly moister area (a mossy hide) helps with shedding.

Avoid dusty or resinous substrates (pine/cedar, toxic). Paper towel makes health monitoring easier. Keep part of the substrate slightly moist without soaking it.

A diurnal species: low to moderate UVB lighting (T5 tube 5 %, UV index ~2-3 in the lit zone with a gradient) is beneficial for metabolism and wellbeing. Not strictly essential if the diet is varied and properly supplemented, but recommended. Also provide a clear day/night cycle.

A large container of clean water available at all times, big enough for drinking and bathing. The animal often defecates in the water: change and clean/disinfect it very regularly to prevent skin and digestive infections.

North America, very widely distributed from southern Canada down to the southern United States (one of the most common snake species on the continent). Some subspecies (e.g. Thamnophis sirtalis tetrataenia, the San Francisco garter snake) are threatened and legally protected: check local regulations and strictly favour captive-bred animals over wild collection.

Opportunistic carnivore (vermivore / piscivore) — Earthworms (nightcrawlers) as a staple, whole thiaminase-free fish, amphibians (with caution), pieces of fish or pinkie rodents scented with fish.

CRITICAL: absolutely avoid fish high in thiaminase (goldfish, carp, minnows/roach), which cause vitamin B1 deficiency and fatal neurological disorders. Safe fish: salmon, trout, tilapia, silversides. Vary the diet and supplement with calcium/vitamins (non-whole prey lacks nutrients). Feed every 4-7 days depending on age; do not feed fish alone.

A very prolific species. Gestation of about 2 to 3 months after spring mating. A winter brumation (controlled cooling) generally triggers breeding. Neonates are independent and feed on their own (often on small earthworms).

• Thiamine (vitamin B1) deficiency from fish high in thiaminase: neurological disorders (tremors, convulsions), potentially fatal
• Internal and external parasites, common especially in wild-caught animals
• Respiratory infections linked to an environment that is too humid, too cold or poorly ventilated
• Stomatitis / mouth infections
• Bacterial dermatitis or skin fungus linked to soiled or overly damp substrate/water