Tree-dwelling. Arboreal species need vertical enclosures with climbing structures. Examples: green tree pythons, crested geckos, panther chameleons. Read more →
Basking
Behavior of seeking warmth from a heat source. Reptiles thermoregulate by basking on the warm side of their enclosure, then moving to cooler areas to cool down.
Brumation
A reptile equivalent of mammalian hibernation. A period of reduced activity, lowered metabolism, and reduced feeding in response to cooler temperatures. Common in Russian tortoises, Hermann's tortoises, garter snakes, and some boas. Read more →
Captive-bred (CB)
An animal born and raised in captivity, not collected from the wild. Captive-bred animals are healthier, less parasitized, and more behaviorally adapted to captivity than wild-caught counterparts. Always preferred.
Convention on International Trade in Endangered Species. International agreement regulating which species can be legally traded between countries. Many tortoises, chameleons, and boas are CITES-listed.
Coil UVB bulb
Compact fluorescent UVB bulb that screws into a standard light socket. Largely obsolete — produces insufficient UVB across the small area it illuminates. Modern care uses linear T5 HO bulbs instead. Linked to MBD in bearded dragons. See our UVB mistake article. Read more →
Crepuscular
Active during twilight (dawn and dusk). Different from nocturnal (night-active) or diurnal (day-active). Leopard geckos are crepuscular. Read more →
D3 (Vitamin D3)
The vitamin reptiles synthesize from UVB exposure that allows them to absorb dietary calcium. Without adequate UVB, reptiles cannot use the calcium they eat — leading to MBD. Read more →
Diurnal
Active during the day. Bearded dragons, panther chameleons, and most monitors are diurnal. Read more →
Display-only
Species that should not be handled regularly. Stress damages the animal even when keepers don't see immediate consequences. Examples: chameleons, green tree pythons, day geckos, axolotls. Read more →
Dubia roach
Blaptica dubia — a feeder insect species. Soft body, high nutrition density, low chitin, easy to gut-load. The current standard feeder for many insectivorous reptiles.
Ectotherm
An animal whose body temperature depends on environmental temperature. All reptiles are ectotherms. They cannot generate body heat metabolically the way mammals (endotherms) can.
Feeding refusal
When a snake or lizard declines food. In ball pythons, often normal seasonal behavior. In other species, often a signal of husbandry problems. See our ball python feeding refusal article. Read more →
Ferguson Zone
A classification system (Ferguson et al., 2010) that groups reptiles by their UVB exposure needs in the wild. Zone 1 (deep shade) through Zone 4 (open sun) guides captive UVB selection.
FT (Frozen-thawed)
Prey that has been frozen, then thawed before feeding. Standard for snake feeding — safer than live prey (no risk of prey-induced injury) and parasite-free.
Gut-load
Feeding nutrient-rich food to feeder insects before offering them to a reptile. Crickets and roaches transfer their stomach contents to the reptile that eats them. Standard gut-load: fresh vegetables, fortified commercial gut-load.
Husbandry
All aspects of how an animal is kept — enclosure, lighting, temperature, humidity, diet, handling. Most pet reptile welfare problems are husbandry problems.
Impaction
Obstruction of the digestive tract by ingested material — typically substrate or oversized prey. Common in leopard geckos kept on loose particulate substrate and fed mealworm-heavy diets. Often fatal in juveniles. Read more →
International Union for Conservation of Nature. Publishes the Red List of species conservation status. Cited on every species page.
MBD (Metabolic Bone Disease)
Skeletal deformity caused by inadequate dietary calcium absorption — typically from insufficient UVB. Manifests as soft jaw, twitching limbs, bone fractures. Permanent if advanced. The leading preventable welfare problem in pet bearded dragons. Read more →
Microchip
An RFID identification chip implanted under a reptile's skin. Permanent identification — recommended for monitors, large boas, tortoises, and valuable individuals.
Morph
A color or pattern variation within a species. Ball pythons, leopard geckos, and corn snakes have hundreds of morphs at various price points.
Mouth rot (Infectious stomatitis)
Bacterial infection of the mouth. Manifests as redness, swelling, discharge. Often a sign of underlying husbandry stress or immune suppression. Vet visit required.
Nocturnal
Active during the night. Ball pythons, most geckos, and pacman frogs are nocturnal or crepuscular. Read more →
Ophidian / Ophiophagous
'Ophidian' means snake-related; 'ophiophagous' means snake-eating. California kingsnakes are ophiophagous — never house with another snake. Read more →
Paludarium
An enclosure that combines aquatic and terrestrial sections. Used for semi-aquatic species like fire-bellied toads and some turtles. Read more →
Pyramiding
Abnormal shell growth in juvenile tortoises that produces raised, pyramid-shaped scutes. Caused by chronic low humidity during development. Permanent. See our tortoise pyramiding article. Read more →
Quarantine
Period of isolation for new acquisitions before introducing them to the rest of the collection. Catches parasites, mites, and respiratory infections before they spread. 30-90 days standard. Read more →
Sexual dimorphism
Visible difference between males and females of a species. Pronounced in panther chameleons (color) and ball pythons (size). Read more →
Substrate
The bedding material at the bottom of an enclosure. Choices vary by species — bioactive substrate, coconut fiber, paper, tile, aspen shavings. Wrong substrate is a leading cause of impaction in leopard geckos. Read more →
T5 HO
T5 High-Output linear fluorescent lighting. The current standard for reptile UVB. Replaced compact coil UVB bulbs around 2015. Brands: Arcadia, Zoo Med Reptisun. Read more →
Thermoregulate
Behavior of moving between warm and cool zones in the enclosure to maintain optimal body temperature. Why proper enclosure temperature gradient matters.
UVB
Ultraviolet B light. The wavelength range (290-315 nm) reptiles use to synthesize vitamin D3 from precursor compounds in the skin. Inadequate UVB causes MBD. Read more →
Wild-caught (WC)
An animal collected from the wild. WC animals are heavily parasitized, behaviorally stressed, and have higher captive mortality. Avoid WC purchases except where conservation context supports it.