Reptile atlas

Geographical Origin and Habitat: This rare species is endemic to the Pacific coast of western Mexico, primarily recorded in the states of Colima, Michoacán, and western Guerrero. It inhabits tropical deciduous forests, medium-stature forests, and dry hilly regions, ranging from near sea level up to approximately 1,000 meters in elevation.

Taxonomy and Genetics: Belonging to the family Viperidae and subfamily Crotalinae (pit vipers). The genus Porthidium comprises small terrestrial pit vipers commonly referred to as hognosed vipers. Phylogenetic studies place *Porthidium hespere* within an arid-adapted clade, with *P. dunni* identified as its closest sister species.

Behavior and Habits: A terrestrial and highly secretive snake that is difficult to locate in the wild. It exhibits nocturnal and crepuscular activity patterns, with increased activity reported during the summer rainy season (June to October) when its primary prey is active. It relies heavily on camouflage to avoid detection.

Morphology: Features a stout body and a distinct triangular head well-differentiated from the neck. The snout is moderately upturned, which is characteristic of the genus. Coloration consists of grey, brown, and beige ground tones, overlaid with a series of dark rectangular blotches aligned along the dorsal spine to aid in camouflage.

Terrarium Setup: Because this is a dangerously venomous species, keeping it is restricted to professionals and authorized institutions. Requires a highly secure, escape-proof terrarium (minimum 32x16x16 inches for an adult) equipped with locking glass doors. The substrate should be a dry mix of coconut husk and leaf litter, with flat stones and low branches for enrichment.

Lighting and Heating: Provide a precise thermal gradient with a cool end of 26°C and a warm basking spot of 30-31°C. Nighttime temperatures can drop to 21-23°C. High-intensity UVB is not required due to their secretive nature, but a regular 12-hour photoperiod should be maintained using low-wattage LED lights.

Humidity and Hydration: Humidity should be adjusted seasonally: 50-60% during dry periods, increasing to 75-85% during the summer rainy season via light misting. A heavy ceramic water bowl must be provided for drinking, along with a humid hide box filled with damp sphagnum moss to assist with shedding.

Feeding and Supplementation: In the wild, they prey on small rodents, lizards, and frogs. In captivity, they feed on appropriately sized thawed mice. Juveniles should be fed every 7-10 days, while adults require feeding only every 14-21 days. Dietary supplements are generally unnecessary if quality prey is used.

Compatibility: Strictly solitary. They must be housed individually to prevent stress and potential cannibalism. The only exception is brief introduction of compatible pairs for breeding purposes, which should only be attempted by highly experienced venomous keepers under close observation.

Health and Common Diseases: Prone to respiratory infections if the enclosure lacks proper ventilation or is kept too wet. Blister disease and scale rot can occur if the substrate is allowed to remain damp for extended periods. Always use professional handling tools such as snake hooks and shift boxes.