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In the field of herpetology (the study of reptiles, turtles, crocodilians, and amphibians), herpetologists (people who study reptiles, turtles, crocodilians, and amphibians) and herpetoculturists (people who raise and breed captive reptiles, turtles, crocodilians, and amphibians) use a great many terms and words that are not a part of most people's everyday vocabularies.  Our Herptological Dictionary is provided to assist you in understanding the meaning of terms that you may not be familiar with.

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Aglyphic: Snakes that do not have fangs for venom delivery.

Albinism, Albino: An animal with absent or deficient melanin or black and brown pigmentation.

Amelanistic: Lacking melanin or black pigment.

Anal Plate: A modified ventral scale that covers and protects the vent (see vent). May be one scale in snakes possessing a single anal plate or two scales side by side in those snakes possessing a divided anal plate. The feature is useful in identifying snakes.

Anerythristic: Lacking normal red pigment.

Antivenin: Horse or sheep serum containing cultured antibodies used to counteract venom in cases of snakebite from a venomous species.

Antivenom: See antivenin.

Arboreal: Living in the trees. A snake that spends most of its time off the ground in the branches and limbs of trees.

Assist Feeding: To start a food item into a snake's mouth and then allow the snake to finish eating on its own.

Axanthic: Lacking normal yellow pigment.

Bask: To lie in a warm area such as in the sun, in order to absorb heat.

Binomial: A scientific name of an snake that is comprised of two parts, genus and species such as Crotalus atrox. Crotalus is the genus for on one group of rattlesnakes and atrox is the species name for the Western Diamondback Rattlesnake. The binomial or scientific name should always be either written in italics or underlined.

Biology: The study of life and all life forms including both animals and plants.

Blue: See Opaque.

Boid: Snakes belonging to the family Boidae. Includes all of the boas and pythons.

Brumate: To place a snake in brumation.

Brumation: The "cooling" a snake by lowering its temperature for usually 2 to 4 months to approximate conditions during the winter period. This is not the same as the true hibernation of mammals. Brumation triggers the physical changes that stimulate egg production in females, sperm production in males and the breeding response necessary for successful captive propagation.

Burrow: To dig underground for shelter or for the purpose of concealment or for the hunting for food. The tunnel created by a burrowing animal.

Cannibal, Cannibalistic: An animal that feeds on others of its own kind.

Carnivorous, Carnivore: A meat eater. An animal that eats the meat of other animals, or in the case of snakes, eats the animal whole. All snakes are carnivorous.

Caudal: Referring to the tail of the snake.

Chordata: The phylum of the animal kingdom that includes all species that have a notochord in either the embryo or the adult. All reptiles, turtles, crocodilians and amphibians belong to the Chordata phylum.

CITES: The Convention on International Trade in Endangered Species of wild flora and fauna. CITES is an international agreement designed to control the international trade in protected species of plants and animals. It became law in the U.S. in 1975.

Class: A taxonomic category for a group of related animals or plants that share common characteristics. This category is between phylum and order. Snakes and lizards belong to the class Reptilia.

Cloaca: The common terminal chamber for the intestinal and urogenital systems in reptiles, turtles, crocodilians and amphibians. Urinary and intestinal wastes collect here before passing out of the body. Eggs pass out of the oviduct through the cloaca when being laid. The cloaca terminates at an opening named the vent.

Clutch: A group of eggs laid by a reptile, turtle, or crocodilian.

Colubrid: a snake belonging to the family Colubridae. Includes many of the more common snakes, such as king snakes, rat snakes, garter snakes, indigo snakes, and others. The vast majority of these snakes and all Colubrid snakes native to the United States are harmless to humans, but there also someColubrid snakes, such as the Boigid snakes, which are rear-fanged and venomous. The venom of these snakes varies in toxicity from mild to very toxic. A gland called the Duvernoy's Gland produces the venom of these snakes.

Cool: To Brumate. To "cool" an snake is to place it in Brumation.

Crepuscular: Being active at dusk or dawn.

Crotalid: A venomous snake belonging to the subfamily Crotalinae which are pit vipers. These snakes have heat sensitive pits on the face and fangs in the front of the upper jaw that fold up against the roof of the mouth. Includes cottonmouths, copperheads, rattlesnakes, cantils, South American pit vipers and Asian pit vipers.

Dead On Road: Refers to a snake or other animal found dead on a roadway having been killed by a passing vehicle. See D.O.R.

Disecdysis: Some or all of the old skin did not shed off as it should have.

Diurnal: Being active during the day.

D. O. R.: See Dead on Road.

Dorsal: Referring to the top surface of the back.

Double clutch: To induce a snake to lay eggs twice in one season.

Double heterozygous (Double het): Being heterozygous for two independent mutant genes, such as albino and anerythristic.

Drop: To lay eggs, or in the case of a live-bearing species, to give birth.

Dry bite: A bite by a venomous snake in which no venom is delivered.

Duvernoy's Gland: A modified saliva gland that produces a type of venom in some Colubrid snakes, varying in toxicity from very mild to extremely very depending on species.

Ecdysis: Shedding of a snake's skin.

Ectoparasite: Parasites that affect an animal externally by attaching themselves to the skin and sucking blood from the host animal. Mites and ticks are ectoparasites in snakes.

Ectotherm: An animal that cannot regulate its own body temperature by an internal mechanism. All reptiles, turtles, crocodilians and amphibians are ectotherms. Also called "cold-blooded" animals. Ectotherms regulate their body temperature by utilizing warm and cool zones in their environment.

Egg-bound: A life:threatening condition that prevents a female snake from laying her eggs. It is usually caused by one or more (usually infertile) eggs adhering to the lining of the oviduct.

Elapid: Venomous snakes with fixed front fangs and usually strong neurotoxic venom. Includes Cobras, Mambas, Kraits, Coral Snakes, Sea Snakes, Taipans, Tiger Snakes, etc. From the family Elapidae. Coral Snakes are the only Elapid snakes in the United States.

Endangered Species: An animal that is considered in danger of extinction. An animal that appears on Appendix I of the Endangered Species Act of 1973.

Endangered Species Act of 1973: A Federal Law that was passed for the purpose of protecting endangered and threatened species of flora and fauna. Enacted in December of 1973 and amended several times since.

Endemic species: A species native to a particular region.

Endoparasite: Parasites of the circulatory, digestive or pulmonary systems of reptiles, turtles, crocodilians and amphibians. These include a variety of round worms, tapeworms, flukes, and protozoans.

Envenomation: The act of delivering venom to a victim by a snake or other venomous animal. The condition of having been envenomated.

Estivation: The lowering of metabolic rate during hot periods or droughts.

Extinct: A species in which all living examples have died. A species that no longer exists in life.

Extirpate, Extirpated: A species that has been eliminated or no longer exists in a particular area where it was formerly found.

Family: A taxonomic category of related species between order and genus.

Force Feed: To feed a snake by force. To use some mechanical means to deliver food to a snake's stomach.

Fossorial: Burrowing. An snake that spends most of it's time in underground burrows or burrowing.

Genus (pl. Genera): A taxonomic category for a group of related animals between family and species. A sub-division of a family.

Gestation: The development of an embryo inside a female animal until it is fully developed and ready for birth.

Gestation Period: The period of egg development while the egg is still inside the female, before laying. The period of time it takes for an embryo to fully develop inside the female in a live-bearing animal.

Glottis: The moveable semi-rigid "tube" in the bottom of a snake's mouth, which facilitates breathing while the snake is swallowing a prey animal.

Gravid: A term used to describe a female snake that is carrying eggs or young.

Hemipenis (pl. Hemipenes): The organ used by a male snake to deposit sperm inside the female's body during mating. A snake has two hemipenes located in the base of the tail, but only one is used at a time.

Herp: A slang term for any and all species of reptiles, turtles, crocodilians, and amphibians. Also used as a verb meaning to look for reptiles or amphibians. (ie. To go herping)

Herper: A slang term for a person who keeps, breeds, or collects reptiles, turtles, crocodilians, or amphibians.

Herpetoculturist: A person who keeps and makes serious efforts to breed reptiles, turtles, crocodilians, or amphibians in captivity.

Herpetofauna: A term for any and all species of reptiles, turtles, crocodilians, and amphibians. Preferred over herp or herptile.

Herpetologist: A person who studies reptiles, turtles, crocodilians, and amphibians. There is no specific degree in herpetology in the United States, but most herpetologists will normally have a degree in biology and zoology, with graduate work in the discipline of herpetology.

Herptile: See herpetofauna.

Het: see heterozygous.

Heterozygous: Having two different alleles of a particular gene in a gene pair. The two alleles may be different mutants or a wild type allele paired with a recessive mutant or a dominant mutant or a codominant mutant. For instance, a crossbreeding between an albino Crotalus atrox and a normal Crotalus atrox will produce offspring that have a normal gene paired with an albino (recessive) gene. These young are heterozygous for albino.

Homozygous: Having two identical alleles for a particular gene in a gene pair (both genes are the same). The genes may be two wild type alleles, two identical dominant alleles, two identical codominant alleles, or two identical recessive alleles.

Hook: A tool used for handling snakes, particularly venomous ones. A handle of varying length and composition with a hook at one end.

Hot: A term used to refer to a venomous snake.

Hybrid: In herpetoculture, the progeny from a breeding between two species of the same genus or between two genera.

IBD: Inclusion Body Disease.

Impaction: A condition where a looped intestine or a plug of some foreign matter makes the snake unable to pass waste material through the intestine to the outside. This is often a fatal condition. It is especially common in smaller captive snakes that are kept on a substrate of sand or other small particulate matter, and caused by accidental ingestion of the substrate.

Incubate: To maintain eggs in conditions favorable to development and hatching.

Incubator: A device used to incubate eggs.

Inclusion Body Disease: An frequently fatal and highly contagious disease seen primarily in Boas and Pythons in which symptoms include neurological impairment, "star:gazing", respiratory disease, and regurgitation. The disease gets it's name because of Cytoplasmic Inclusion Bodies seen in certain tissues of infected animals upon microscopic examination. Inclusion Body Disease is thought to be caused by a retrovirus. Also see IBD.

Infralabial: The scales on the lower lip of a snake.

Intergrade: A reptile, turtle, crocodilian, or amphibian that comes from an area where the ranges of two subspecies meet and that shows some characteristics of both subspecies.

Insectivorous, Insectivore: A species that feeds on insects. Insect eater.

Jacobson's Organ: The olfactory organ in the roof of a snake's mouth in which it inserts the tips of its tongue after sampling its surroundings. This organ provides for the senses of taste and smell.

Juvenile: A young animal, not yet sexually mature.

Keeled scale: A scale that has a narrow ridge (median ridge) running down the center from front to rear. Keeled scales give a reptile a somewhat rough appearance and feel.

Labial: Pertaining to the lips.

Labial scales: The lip scales of snakes.

Labial pits: Heat sensitive pits present on the lips of Boas and Pythons.

Lacy Act: Aa Federal Law enacted in 1900 for the purpose of regulating the transport of protected or injurious species across state lines or internationally in violation of those states or country's laws.

Lateral: On the side, as in the stripe along the side of a Garter Snake.

Leucism, Leucistic: A hereditary chromatophore defect involvubg all chromatophores. An all-white animal.

Litter: The group of babies to which a live-bearing reptile gives birth.

Loreal: The scale between the nasal scales and the preocular scales.

Loreal Pit: Heat-sensitive pit located within the loreal scale on pit vipers.

Median Ridge: The ridge down the center of a keeled scale.

Melanistic: Having an excess of black pigment or melanin.

Mental Groove: The groove in the skin along the midline of the lower jaw. It allows great expansion of the lower jaw during feeding.

Monotypic: A species with no subspecies.

Monovalent: Being effective against only one kind, as in Monovalent Antivenin. Only effective against the venom of one particular genus or species of snake.

Morph: Usually refers to the various colorations and patterns produced by one mutation or a combination of mutations in a particular species.

Mouth Rot: See Stomatitis.

Musk: A foul smelling substance produced by scent glands in the base of the tail of some snakes. Discharging musk from the vent may discourage an attacker.

Neonate: A newly hatched or newborn reptile.

Nocturnal: Active at night.

Ocular: Referring to the eye. Ocular scales are those contacting the eye. They are divided into 4 groups, preoculars, supraoculars, suboculars, and postoculars.

Opaque: Used to describe the part of a snake's shed cycle when its eyecaps are "cloudy" or "blue".

Ophidian Paramyxovirus: A highly contagious virus related to Hantavirus that infects snakes in captive collections and is usually fatal. It is most commonly seen in Viperid snakes, but has been reported in others recently. Also known as OPMV.

Ophiophagous: Feeding on snakes. Kingsnakes and cobras are ophiophagous.

Opisthoglyphic: Rear-fanged snakes.

OPMV: See Ophidian Paramyxovirus.

Oviparous: Egg-laying.

Phenotype: The visible characteristics of an animal. The things about a snake which can be observed, such as general appearance, physical characteristics, behavior, etc., which are caused by genes which can be passed on to subsequent generations. See genotype.

Pinkie Press: A trade name for a device designed to facilitate force feeding snakes newborn mice.

Pip: The act, by a baby reptile, turtle or crocodilian, of cutting it's way out of the egg using a special egg tooth or caruncle.

Pit: A heat sensitive organ in crotalid snakes and some boids. In pit vipers (crotalids) it is located between the nostril and the eye. In boids there are several located on the lips. Used to help locate warm-blooded prey.

Polyvalent: Being effective against more than one type, as in Polyvalent Antivenin. Antivenin that is effective against the venoms of more than one species of snake.

Pop: To sex a snake by everting the hemipenes. Usually done on neonate snakes.

Postocular: The scales just behind the eye.

Prehensile: Grasping. A prehensile tail describes a tail that is capable of grasping.

Preocular: The scales just forward of the eye.

Prey: An animal that is captured and eaten for food.

Probe: The probe used for sexing snakes, or the act of using a probe to sex a snake. This probe is usually made of surgical steel, is tapered and has a "ball-end" in most cases. There are various sizes for use on smaller or larger snakes. The probe is inserted through the vent to check for the presence of a hemipenis.

Protected species: A species that is protected by either federal or state law and cannot be legally captured or taken without a specific permit to do so.

Proteroglyphic: Snakes that have fixed front fangs. Elapid snakes such as coral snakes and cobras are proteroglyphic.

Range: The geographic area in which a particular species is known to occur naturally.

Recessive: A mutant gene that changes the phenotype from normal only when two identical mutant genes are present. When a recessive mutant gene is paired with a normal gene, the snake looks normal.

Regurgitate: To vomit. In snakes, to bring partially digested food items back up from the stomach and out of the mouth. Usually caused by some irritation of the stomach by parasites or bacterial or viral infections, or by temperatures that are too high or too low.

Reptilia: The taxonomic class of vertebrates that includes snakes and lizards. For many years turtles, tortoises and crocodilians were also included in this taxonomic class. However, recent taxonomic revisons have placed crocodilians along with turtles and tortoises into their own respective taxonomic classes seperate from Reptilia.

Restraining Tube: A plastic tube normally used for the purpose of restraining venomous snakes so that medical procedures, etc. can be safely performed.

Retained Eyecap: A condition in which a snake fails to shed the transparent skin structure that covers each eye along with the rest of his skin.

Road Cruising: Driving slowly on a road, normally at night, looking for snakes on and along side of the road.

Rostral: Referring to the tip of the snout. The scale on the end of a snake's snout is the rostral scute.

Rough: A term used to describe reptiles that have keeled scales.

Scale clip: To mark a snake or lizard for later identification by clipping scales in a particular pattern.

Scute: the large scales on the head and venter of snakes are sometimes referred to as a scutes.

Serum: Antivenin made using horse or sheep serum.

Serum Sickness: An allergic reaction in humans to animal serum, often seen in cases of snakebite where antivenin is administered.

Shed: A skin that has been shed by a snake. See ecdysis.

Smooth: A term used to describe a reptile that has smooth scales.

Smooth Scale: A scale that has no median ridge. Smooth scales give a snake a glossy, shiny appearance and a smooth leather-like feel.

Species: The taxonomic category that subdivides a genus into groups of a particular kind of animal.

Speculum (pl. Specula): A device, usually a wire loop, designed to keep an animal's mouth open for the purpose of performing oral medical procedures or force feeding.

Spur: A small appendage located on either side of the vent in Boas and Pythons. Vestigial hindlimbs. They are more pronounced in males.

Solenoglyph: A solenoglyphic snake. A venomous snake that has moveable fangs, which fold up against the roof of the mouth when not in use. Viperid and crotalid snakes are solenoglyphic.

Stomatitis: An infection of the lining of a reptile's mouth. It is usually caused by bacteria and is characterized by a cheesy discharge from the lesions and unwillingness to feed. Severe cases can cause death. Also known as mouth rot.

Sub-Adult: A juvenile animal that is nearing sexual maturity.

Subcaudal: referring to the underside of the tail.

Subocular: The scales located just below the eye and above the supralabial scales, in between the lip and the eye. Subocular scales are not present in all snakes.

Subspecies: A taxonomic division of a species into geographic races.

Supralabial: The scales on the upper lip.

Supraocular: The scales just above the eye.

Sympatric: Species that occur within the same geographic range without interbreeding.

Taxonomic Classification Order: The Basic Linnaean System of Classification of animals and plants. The proper order of such classification is as follows: Kingdom, Phylum, Class, Order, Family, Genus, Species, Subspecies (if any). See the below example showing the Basic Taxonomic Classification Order of the Trans-Pecos Copperhead.

Basic Taxomomic Classification Order for the Trans-Pecos Copperhead

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Viperidae
Genus: Agkistrodon
Species: Agkistrodon contortrix (always a binomial)
Subspecies: Agkistrodon contortrix pictigaster (always a trinomial)

Scientific names are always made up of the genus, species and subspecies (if any). So, the scientific name for the Trans-Pecos Copperhead would be Agkistrodon contortrix pictigaster.

Taxonomy: The systematic naming of animals and plants. The scientific name of a plant or an animal.

Terrestrial: Living on the ground. A species that spends most of its time on the ground.

Thermoregulate: Moving from a warm area to a cooler one or vice-versa in order to regulate body temperature.

Threatened: A species that is not yet endangered, but is in danger of becoming endangered. A species that appears on Appendix II of the Endangered Species Act or on any state list of protected species as having a threatened status.

Tongs: A tool for handling venomous snakes. A handle of varying length with a lever at one end that is connected by a cable to jaws at the other end. The jaws are for grasping the snake's body while keeping the animal a safe distance from the handler.

Triad: A group of three rings, usually red, white (or yellow) and black, encircling nearly encircling the body of a snake and repeating for the length of the body. Usually aeen in coral snakes, milk snakes and mountain kingsnakes.

Tri-Color: Refers to the pattern of rings comprised of three colors, usually red, white(or yellow) and black found in coral snakes, milk snakes and mountain kingsnakes. These snakes are sometimes referred to as "tri-colors".

Trinomial: A scientific name comprised of three parts, the genus, species and subspecies. Ex. Agkistrodon contortrix pictigaster.

Triple Heterozygous (Triple Het): Being heterozygous for three independent mutant genes.

Tube Feed: To force-feed an animal or deliver medication by use of a tube and syringe.

Venom: A toxic compound secreted by some snakes for the purpose of defense or obtaining prey.

Venom Gland: A modified saliva gland, located at the back of the upper jaw in venomous snakes, which produces the venom. The venom moves from the gland to the fangs via the venom duct. Venom glands are present in Crotalid, Viperid and Elapid snakes.

Venemoid: A naturally venomous snake that has been made non-venomous by surgical means.

Vent: The opening at the end of the cloaca where urinary waste, intestinal waste, and eggs leave a reptile, turtle, crocodilian, or amphbbian's body. Externally, it is usually on animal's underside and marks the end of the body and beginning of the tail.

Venter, Ventral: Pertaining to the belly of a reptile, turtle, crocodilian, or amphibian.

Ventral Scales: Scales located on the belly of a reptile, turtle, crocodilian, or amphibian.

Viperid: Snakes belonging to the subfamily of true vipers, Viperinae. These snakes have fangs in the front of the upper jaw that fold up against the roof of the mouth, like crotalids. But they lack the crotalids' heat sensitive facial pits. Gaboon Vipers, Puff adders and European Vipers are some examples of viperid snakes.There are no viperid snakes native to the United States.

Viviparous: Bearing live young instead of laying eggs.

Xanthic: Yellow or orange in color.

Zoology: A branch of biology that deals with the study of animals and aspects of animal life.


Bechtel, H. Bernard. 1995. Reptile and Amphibian Variants - Colors, Patterns , and Scales. Krieger Publishing Co. Malabar, Fl.

Peters, James A. 1964. Dictionary of Herpetology. Hafner Publishing Co. New York and London.

Wareham, David C. 1993. The Reptile and Amphibian Keeper's Dictionary. Blandford Press. London.

Webster's Ninth New Collegiate Dictionary. 1983. Merriam-Webster, Inc. Springfield.

Last updated January 13, 2008.

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