Reptile atlas

Geographical Origin and Habitat: *Porthidium yucatanicum* (Yucatán Hognose Viper) is a venomous snake endemic to the Yucatán Peninsula in southern Mexico. It inhabits tropical dry deciduous forests, semi-arid thorny scrublands, and coastal grasslands. This region is characterized by a tropical climate with a long, pronounced dry season and sandy, limestone-rich soils.

Taxonomy and Genetics: Belonging to the family Viperidae, subfamily Crotalinae. The genus *Porthidium* is characterized by its upturned snout, which is an adaptation for digging or leaf-litter foraging. Genetic analysis shows this species is closely adapted to the isolated and dry ecological niche of the northern Yucatan peninsula.

Behavior and Habits: Terrestrial and primarily crepuscular or nocturnal. It spends the hot daylight hours hidden beneath rocks, fallen logs, or leaf litter to prevent dehydration. It is an ambush predator that relies on camouflage to capture prey. Although generally non-aggressive, it will strike defensively if stepped on.

Morphology: A small, stout-bodied pit viper, with adult lengths ranging from 35 to 45 cm. It features a wide, triangular head with a distinct upturned rostral scale. The body coloration is greyish-brown or tan, patterned with a series of dark rectangular blotches along the spine, divided by a thin, light-colored vertebral line.

Terrarium Setup: Requires a horizontal, escape-proof terrarium of at least 80 liters equipped with a secure lock. The substrate should be dry and loose, such as aspen shavings or cypress mulch. Provide several dry hides throughout the enclosure and a dedicated humid hide filled with damp sphagnum moss to aid in molting.

Lighting and Heating: Establish a horizontal thermal gradient. The warm side should have a basking temperature of 30-32 °C using a heating pad or overhead halogen spot, while the cool side should hover around 24-25 °C. Nighttime temperatures can drop to 20-22 °C. A 12-hour light cycle is recommended using low-output UVB lamps.

Humidity and Hydration: Keep ambient humidity low, around 40-50%, mimicking its semi-arid habitat. The humid hide must be misted weekly to keep the moss damp. Provide a small, heavy water dish with fresh water on the cool side of the terrarium, ensuring it cannot be easily tipped over.

Feeding and Supplementation: In the wild, they feed on lizards, frogs, and small rodents. In captivity, they feed on appropriately sized frozen-thawed mice. Always use long feeding tongs to offer food. Avoid feeding live prey to prevent injury. Dust prey with calcium powder once a month.

Compatibility: Strictly solitary. Keep individuals in separate enclosures to prevent cannibalism and stress. As a venomous reptile, it must never be handled directly. Use professional snake hooks and safety shifting boxes during cleaning and maintenance of the enclosure.

Health and Common Diseases: Prone to blister disease and scale rot if kept on damp or soiled substrate. Conversely, lack of a humid hide can lead to stuck shed (dysecdysis), particularly around the eyes (retained spectacles). Good ventilation is critical to prevent respiratory issues.