Common Cantil

🔤 Taxonomy

Agkistrodon bilineatus is the accepted name for the common cantil. Older broad accounts also included A. taylori, A. russeolus and A. howardgloydi. Keep original locality and parentage rather than treating every “Mexican moccasin” as interchangeable. This is a pit viper, not a harmless watersnake.

📌 Description

A stocky, mainly terrestrial ambush predator, often about 60-100 cm. Pale facial lines contrast with a dark body. Its “moccasin” name does not justify a permanently wet aquarium: sheltered floor space and dry resting sites are essential. Reliable modern-species longevity estimates are lacking.

The active-season values below are provisional management starting points, not demonstrated physiological optima or safety limits. Enclosure dimensions are practical recommendations for one adult; increase them for a larger individual. Confirm the plan with an experienced reptile veterinarian and retain locality records.

📋 Quick reference

Care point	Provisional active-season target
Adult length	60-100 cm
Enclosure, one adult	120 × 60 × 60 cm
Ambient air	24-28°C
Basking surface	30-32°C
Cool retreat	22-24°C
Night air	20-24°C
Relative humidity	50-70%
Adult meals	14-21 days

☠️ Venom

Potential effects include severe pain, swelling, tissue damage, bleeding and systemic illness. Studies distinguish cantil venom from that of US copperheads; a genus name alone cannot determine treatment. Central American medical guidance discusses regional polyvalent antivenom, but the receiving hospital must verify the exact species, product and current availability. Severity varies; a small wound does not rule out serious or delayed envenoming.

Treat every bite as an emergency, including an apparently dry bite. Move away, call emergency services, keep the person still, remove rings and support the limb without compression. Do not cut, suck, ice or tourniquet the wound, and do not catch the snake. Follow poison-centre instructions. Agree a receiving hospital and antivenom access before acquisition; treatment belongs in hospital.

🌍 Distribution

Western and southern Mexico, Guatemala, El Salvador and a limited western Honduran record. The latter is based on photographic evidence cited by the taxonomic account. Dry forest and seasonally humid lowlands are important habitats. Former records extending to Costa Rica often concern the now-separated A. howardgloydi. Country shading is not a continuous distribution.

Native-range context; shaded countries do not imply continuous occupation

🌡 Climate across the native range

Monthly outdoor normals for 1991–2020 illustrate seasonal and regional differences, not enclosure settings. These approximate landscape coordinates are not exact snake records.

Chamela, Jalisco — Mexico

View location on Google Maps

Month	Min °C	Mean °C	Max °C	RH %
January	18.9	23.3	28.4	75
February	18.6	23.1	28.3	76
March	18.4	23.2	28.5	75
April	19.1	23.9	29	75
May	21.4	25.5	30	75
June	24	26.8	30.4	79
July	24.5	27.2	30.5	83
August	24.4	27	30.2	85
September	24.1	26.3	29.3	87
October	23.7	26.3	29.4	86
November	21.9	25.3	29.5	81
December	19.9	23.9	28.7	77

Escuintla lowlands — Guatemala

View location on Google Maps

Month	Min °C	Mean °C	Max °C	RH %
January	19	24.1	30.3	66
February	19.1	24.7	31.2	65
March	19.7	25.4	31.6	66
April	20.5	25.6	31	73
May	20.7	24.7	29	84
June	20.4	24.1	28.1	88
July	20.1	24.3	28.7	85
August	20	24.1	28.5	87
September	19.9	23.5	27.6	89
October	19.5	23.3	27.6	88
November	19.2	23.4	28.4	81
December	19.1	23.7	29.4	73

Weather data by Open-Meteo.com · CC BY 4.0 · Monthly normals calculated by Herpeton Academy from daily archive values.

⚖️ Legal status

No CITES or specific EU wildlife-trade annex listing was found. Mexican official conservation material lists A. bilineatus under special protection (Pr); collection and export cannot be presumed lawful. Check current national implementation and the original stock records before transfer.

The Bern Convention is not a relevant native-range protection framework for this American species; this does not remove national wildlife or dangerous-animal restrictions.

Legal review: 17 September 2026. National capture, possession, registration, breeding, sale and transport rules may be stricter. Verify permits before transfer and keep invoices, breeder identity, parentage and import records. Trade status does not itself authorize keeping a venomous snake.

🤌 Husbandry

Keep Agkistrodon bilineatus individually in a locked enclosure within an access-controlled venomous-reptile room. Secondary containment and a lockable shift compartment should permit water changes and cleaning only after the animal has been isolated and visually accounted for. Free-handling is unacceptable. Prepare written bite and escape plans, trained backup cover and a veterinary arrangement before acquisition.

Quarantine for at least 90 days as a working minimum, longer when the veterinarian advises. Use separate tools and a simple enclosure; record feeding, sheds, faeces and body condition. Arrange parasite screening for uncertain-origin animals or abnormal stools. Weigh only through an established protected-contact procedure.

💡 Lighting

Provide about 12-14 hours of visible light during the active season, with darkness at night and shaded retreats. A species-specific UVB requirement has not been demonstrated. If low-level UVB is used, measure exposure and retain complete shade; do not infer lamp strength from habitat photographs. Guard lamps and wiring against contact.

🌡 Heating and temperature

Begin with air at 24-28°C, a local basking surface at 30-32°C, a cool retreat at 22-24°C and night air at 20-24°C. These are cautious working bands, not tolerance limits. Measure air, surface and cool-hide temperatures separately. Thermostat-control heating; check the room during summer because a thermostat cannot cool hot air.

Seasonal cooling requires a documented, locality-specific plan for healthy, established adults. Do not cool new arrivals, thin, sick or gravid animals, or copy an adult breeding cycle onto juveniles. Outdoor monthly normals are not brumation instructions.

The starting bands are comparative husbandry recommendations, not a study of this species’ limits. For tropical-source cantils, do not impose deep winter cooling from a North American copperhead schedule. Maintain drinking water through any planned drier season.

💧 Humidity and water

Use 50-70% relative humidity as an initial management band, with ventilation and a mostly dry resting surface. Provide a small locally moist retreat during shedding without wetting the whole enclosure. Offer clean drinking water continuously in a stable, shallow bowl, serviced through the protected system. Dry habitat does not mean absence of water. Persistent condensation or repeated retained sheds needs review; never peel skin or force soaking.

🌿 Enclosure and decoration

Use at least the practical 120 × 60 × 60 cm layout in the table and allow the snake to stretch fully. Check door gaps, vents and cable holes against the smallest animal housed. Fix rocks directly to the enclosure base so excavation cannot undermine them; retain clear sightlines to shift doors. Avoid sharp gravel, aromatic wood and unstable piles. Remove waste after securing the snake.

After quarantine, use about 5-8 cm of compactable soil and washed sand with dry leaf litter and securely supported bark shelters. Retain a small moist refuge rather than a wet floor. Keep cover away from the shift-door track so a concealed cantil cannot prevent safe closure. Paper facilitates quarantine and faecal inspection.

🐁 Feeding

Acquire an individual already taking thawed whole mice. Use prey no wider than the thickest body section; juveniles need smaller meals, initially about every 7-10 days. Field prey variety does not justify collecting wild frogs or lizards. Record refusals and weight trends rather than offering larger meals.

The table gives an initial adult feeding interval of 14-21 days; adjust portions and timing to weight trend and condition. Deliver food through the collection’s protected feeding system. Avoid live rodents and substrate-coated food; dehydration, low temperatures and oversized meals increase regurgitation and impaction concerns. Whole prey normally needs no routine calcium or vitamin dusting. Do not improvise supplementation or force-feeding.

🥚 Breeding

Live-bearing; there is no egg incubation programme. Published zoo breeding confirms that reproduction is possible, but a single timetable is not established across localities. Have sex assessed professionally and pair only mature, healthy animals with a documented recovery period. Cantils can eat other snakes: separate housing is a welfare requirement, not just a feeding convenience.

Breeding adds exposure risk. Prepare separate, escape-proof neonatal housing before pairing, avoid permanent cohabitation, and retain parentage, dates, meals and transfer records. Only breed when lawful placements and competent staff are available.

🩺 Common problems

Overheating: repeated escape attempts or unusual exposed resting require immediate measurement of the cool retreat.
Dysecdysis and dehydration: review drinking access and the moist refuge; repeated problems need veterinary assessment.
Respiratory infection or stomatitis: wheezing, bubbles or oral discharge require prompt professional care.
Dermatitis, impaction, obesity and parasites: dirty wet bedding, substrate ingestion, excessive feeding or persistent weight loss need correction and diagnosis. Do not use automatic deworming or home restraint.

📌 Conclusion

For the common cantil, verified identity and solitary housing come before colour or feeding enthusiasm. Resolve Mexican source protection and antivenom logistics before acquiring an animal sold under a broad old label.

📚 Sources and further reading

ReptiFiles was checked first on 17 September 2026; no species-specific guide was found. Numerical recommendations are separated from directly reported breeding outcomes. Historical care reports are not current medical instructions.