snake

Diagnostic anatomy

Record visible scales, body form, head features and tail configuration, distinguishing absent features from features that could not be seen.

1. Which observed anatomical features support recognising this subject as a snake? definition
2. What evidence distinguishes it from a legless lizard, caecilian, worm or shed skin? boundary

Identity evidence

Associate identification with locality, diagnostic observations and a traceable reference or expert assessment; keep individual matching separate.

1. Which reference or expert assessment supports the proposed taxon, and which alternatives remain? provenance
2. What markings, custody records or other evidence justify treating successive observations as the same individual? boundary

Condition and shed record

Record comparable size observations and visible skin condition, including suspected retained shed near the eyes or tail tip without attempting removal.

1. What length, mass or body-profile observations are available, and how were they obtained? measurement
2. Where are visible lesions or suspected retained shed, and how have they changed between dated observations? measurement
3. Which observed changes warrant professional assessment before further manipulation? action

Life-stage evidence

Separate known history from inferred maturity, sex or reproductive condition.

1. What dated history or qualified assessment supports the recorded life stage, sex or reproductive condition? provenance
2. Which apparent changes could reflect feeding or body condition rather than reproduction? boundary

Activity in context

Record posture and locomotion alongside immediate conditions without assigning a cause from one observation.

1. What movement, posture or refuge use was observed, for how long and under what disturbance? measurement
2. What temperatures and access to cover were recorded at the snake's location, and by what method? measurement
3. What additional evidence is needed before interpreting low activity as a condition requiring intervention? boundary

Intake history

Track feeding events, refusals, regurgitation and water availability while separating observed facts from keeper reports.

1. What feeding, drinking or regurgitation events were observed or reported, and when? provenance
2. For a captive snake, what verified taxon-specific guidance supports changing prey provision or water access? action

Hazard with uncertainty

Retain unresolved venom status and record barriers, proximity and reported contact without relying on head shape or colour alone.

1. What reliable taxon identification and source support the venom hazard assessment, or does it remain unresolved? provenance
2. Can people or domestic animals reach the snake, and what barriers or escape routes are present? boundary
3. What immediate access restriction or qualified-response referral is justified by the observed encounter? action

Intervention basis

Record whether the snake is wild, captive or a suspected escape, who is responsible, and what evidence supports any proposed intervention.

1. What evidence establishes custody or escape status, and who is responsible for the next decision? provenance
2. Before capture, transport or release, which local requirements and responder qualifications must be verified? action
3. Does the observed situation justify intervention, continued distant observation or specialist assessment? action

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Vipers (Viperidae), including true vipers and pit vipers, with folding front fangs
• Elapids (Elapidae), including cobras, kraits, mambas and coral snakes, with fixed front fangs
• Sea snakes and sea kraits (Hydrophiinae and Laticaudinae, nested in Elapidae in current taxonomy but treated separately in practice)
• Pythons (Pythonidae), Old-World constrictors
• Boas (Boidae), New-World and Madagascan constrictors and relatives
• Typical colubrid snakes (Colubridae), the majority of species, mostly non-front-fanged
• Blind snakes and thread snakes (Scolecophidia: Typhlopidae, Leptotyphlopidae and allies)
• Rear-fanged colubroids of medical interest (selected Atractaspididae, Lamprophiidae and opisthoglyphous colubrids)

1. Which of these kinds and varieties hold for the sense of snake this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• NCBI Taxonomy - 8570 - Taxon Serpentes (snakes).
• ITIS TSN - 174118 - Suborder Serpentes in the Integrated Taxonomic Information System.
• Wikidata - Q2102 - Item for snake / Serpentes; species and families have their own Q-ids.
• CITES listing - family- or species-level listings (e.g. Pythonidae spp. App. II; selected App. I taxa) - No single code for all snakes; higher-taxon listings cover many constrictors.
• IUCN Red List - species-level assessments under Serpentes - Conservation status is assigned per species, not to snakes as a whole.

1. Which of these identifiers and schemes hold for the sense of snake this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• CITES Appendices I-III (CITES Secretariat / UNEP) control international trade in many pythons, boas and listed venomous or look-alike species.
• EU Wildlife Trade Regulations implement CITES for import, export and commercial use in the European Union.
• U.S. Endangered Species Act and Lacey Act (U.S. Fish and Wildlife Service) restrict take and trade of listed snake species and of wildlife taken in violation of other laws.
• WHO Guidelines for the Production, Control and Regulation of Snake Antivenom Immunoglobulins (World Health Organization) govern antivenom quality and the list of medically important species.
• National and subnational wildlife and dangerous-animal laws (various ministries and states) license or ban keeping of venomous snakes and large constrictors.
• Invasive-species rules, e.g. U.S. injurious-wildlife listings and Florida python control (USFWS / state agencies), restrict possession and transport of some non-native constrictors.

1. Which of these standards and regulation hold for the sense of snake this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Wild predators of rodents, amphibians, birds, other reptiles and (in large species) mammals, encountered in agriculture, forests, wetlands and human settlements.
• Cause of snakebite envenoming in rural tropical work, especially farming and walking at night without protective footwear.
• Captive animals in zoos, laboratories and the pet trade (corn snakes, ball pythons, kingsnakes and others).
• Skins of pythons and boas used in the luxury leather trade under CITES permits.
• Venom extracted for antivenom production and for toxin and drug research.
• Food and traditional medicine in parts of East and Southeast Asia and West Africa.
• Invasive predators, notably Burmese pythons in the Florida Everglades, collapsing native mammal populations.
• Cultural and religious symbols (e.g. Nagas, Asclepius staff, indigenous Australian and Mesoamerican iconography).

1. Which of these real-world use hold for the sense of snake this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Total body length (tiny scolecophidians to giant constrictors) - 0.10-7 - m
• Body mass - 0.001-200 - kg
• Extant species richness of Serpentes - 3900-4100 - species
• Precloacal (body) vertebrae - 120-400 - count
• Preferred body temperature in active terrestrial species - 25-32 - °C
• Global snakebite deaths per year (WHO estimates) - 81000-138000 - deaths/year
• Clutch or litter size - 1-100 - offspring

1. Which of these typical measurements hold for the sense of snake this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Envenoming after a bite: neurotoxic, hemotoxic, cytotoxic or mixed syndromes, with local necrosis, coagulopathy, paralysis, shock or death.
• Wrong or delayed antivenom, or no antivenom available, worsening outcome after a medically important bite.
• Misidentification of a venomous species as harmless (or the reverse), leading to delayed care or unnecessary killing.
• Constriction and asphyxia by large pythons or boas, rare in humans but documented in keepers and, exceptionally, in the wild.
• Salmonella and other zoonotic infections from handling captive snakes or cleaning enclosures.
• Invasive predation and ecological collapse where non-native constrictors establish.
• Overharvest for skins, meat, medicine or the pet trade, depleting wild populations.
• Persecution of non-venomous snakes driven by fear, removing rodent predators from farmland.
• Secondary bacterial infection of bite wounds and traditional first-aid harms (tourniquets, cutting, sucking).

1. Which of these failure modes and hazards hold for the sense of snake this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Medically important genera differ by region: Bothrops in Latin America, Crotalus in the Americas, Echis and Naja in Africa and the Middle East, Naja and Bungarus in South Asia, Notechis and other elapids in Australia (no viperids on the Australian mainland).
• Sea snakes are Indo-Pacific; they are effectively absent from the Atlantic.
• British 'adder' is Vipera berus; in North America 'adder' is used loosely and is not a reliable name.
• Coral-snake mimicry rhymes (red on yellow, etc.) are valid only for some New World coral snakes and fail elsewhere.
• Australia's serious land snakes are elapids; Madagascar has boas and none of the typical African vipers or cobras.
• Python vs boa is a biogeographic and taxonomic split (Old World pythons vs New World/Madagascan boas) that the pet trade still uses as everyday kinds.
• Legal keeping of venomous snakes and giant constrictors ranges from licensed husbandry to outright bans, varying by country and U.S. state.
• Use as food or medicine is concentrated in parts of East and Southeast Asia and West Africa, unlike the Western pet-and-zoo pattern.

1. Which of these regional variation hold for the sense of snake this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Legless lizards (glass lizards, slow worms, pygopodids) - Most retain movable eyelids and an external ear opening, a less deeply forked tongue, and often a lateral body groove; many autotomize the tail. Snakes have a spectacle, no external ear opening, a deeply forked tongue, and do not shed the tail as a regular escape.
• Amphisbaenians (worm lizards) - Short, often annulated bodies with a reinforced snout for burrowing and reduced eyes under skin; not the elongate, kinetic-skulled form of Serpentes.
• Caecilians - Lissamphibians with moist, glandular skin, no epidermal scales on the surface, and an amphibian skull; snakes are dry-scaled reptiles.
• Eels and eel-like fishes - Aquatic vertebrates with gills and fins (or fin folds) and no keratinous scales of the squamate type; snakes breathe air with lungs and have a forked tongue.
• Earthworms and other annelids - No vertebrae, no scales, no skull; segmentation is soft-bodied. Even tiny blind snakes have a skull, scales and a vertebral column.
• Harmless mimics of venomous snakes (e.g. kingsnakes vs New World coral snakes) - Head shape, pupil, loreal pit, scale characters and (only in limited regions) colour-ring sequence; field identification should not rely on a single mnemonic.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of snake this model covers, and on what evidence? provenance