Reptilia · Squamata
Helicops infrataeniatusJan, 1865
Brazilian Keelback
Photograph by Diogo B. Provete, CC BY-SA, via Wikimedia Commons
A water-living, active by day or night, meat-eating snake from the Neotropic region, reaching 100 cm nose to tail.
Reptilia › Squamata › Colubridae › Helicops
- Grows to
- 1000mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Cathemeral
- Lives
- Aquatic
Longer than 70% of all colubrid snakes anyone has measured.
The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 98 to 3,800 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.
What is known
37 sourced facts, each taken from a named scientific dataset. How to read these.
Cited from a dataset unless a row is marked otherwise.
Standing in the world
- Still living
- Extant
- Conservation status
- Least Concern
- Status assessed · the year the Red List last looked
- 2014
- Population trend
- Stable
The animal itself
- Limbs
- None
- Pupil
- Round
- Venomous
- Yes
- Fangs
- At the back of the mouth
Size
- Length snout to vent · greatest recorded
- 603mm23.5 in
- Length nose to tail · greatest recorded
- 1000mm3 ft 3 in
- Female length · mean, nose to tail
- 551mm21.5 in
- Hatchling length · snout to vent
- 141.5mm5.5 in
- Hatchling length · nose to tail
- 191.5mm7.5 in
- Body mass · greatestcomputed
- 70.68g2.5 oz
- Body mass · adult female, meanmeasured
- 62.5g2.2 oz
- Body mass at hatchingmeasured
- 2.35g0.08 oz
1000 mm total length (Feldman et al. 2016), Cabral et al. 2022 (max Total length 693 mm, Max SVL: 500 mm), Regnet et al. 2022 (160 adult females SVL 29.3–60.3 mean 41.7±8 CM, total length 40.1–77.4 mean 55.1±10.1 cm, weight 20.6–191 mean 62.5±36.7 g; 177 adult males 27.9–46.7, mean 34.2±4.1 cm SVL, 40.1–67, mean 49.6±6.1 total length, weight 15–61.3 mean 30.7±9.7 g, hatchlings 13.3–15 cm SVL, 18.4–19.9 cm total length, 2.2-4 g)
snakes only in this source
computed from length by a family-level allometric equation, not weighed
How it lives
- Diet
- Carnivorous
- How it hunts
- Active foraging
- Active
- Cathemeral
- Where it lives
- Aquatic
- Habitat
- Forest, Grassland, Savanna
- Biome
- Tropical & Subtropical Grasslands, Savannas & Shrublands
- Region
- Neotropic
- Mainland or island
- Mainland
- Elevation · above sea level
- 24–1026m
- Range size
- 2,210,757km²
Amphibians, Fish (Ramirez et al. 2023
Rahhal et al. 2023
Feldman 2015
Breeding
- Reproduction
- Viviparous
- Average clutch
- 18eggs
- Eggs or young per clutch
- 1–25eggs
- Mean clutch
- 10.2eggs
Feldman et al. 2015, Meiri et al. 2019, Moraes-da-Silva et al. 2022
1-25 mean=10.2 (Cobos & Sanchez 2019)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Jan
- Moved to another genus · since it was first described
- No
- Described in
- 1865
- Type locality
- Brazil
Keeping one
3 ft 3 in × 19.5 in × 2 ft 6 in(100 × 50 × 75 cm)
Minimum length × width × height, for one animal. Bigger is always better.
The standard sizes snakes as a fraction of total length: 1 × 0.5 × 0.75.
Spends time in water, so a water area is part of the enclosure rather than a dish.
Mindestanforderungen an die Haltung von Reptilien (Sachverständigengutachten), German Federal Ministry for Nutrition, Agriculture and Forestry, Animal Welfare Division, 10 January 1997. The standard states these floor areas are recommendations rather than binding limits.
From this animal’s own total length of 3 ft 3 in (1000 mm), at 1 × 0.5 × 0.75 times it, following the German federal welfare standard — how this is worked out.
No preferred body temperature has been recorded for Brazilian Keelback. Rather than repeat a number from a care sheet, this page leaves it out.
Feeding
A prey item should be between the same width as the widest part of the snake's body and about 1.5 times that width.
Widely used across snake husbandry references. An alternative formulation gives prey at 10-15% of the snake's body mass. This is established practice, not a measurement.
9kJ per day
Worked out for an animal of 71 g, the heaviest recorded for Brazilian Keelback — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.
An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.
What nobody knows
These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.
- — Length snout to vent · adult female mean
- — Length snout to vent · adult male mean
- — Length snout to vent · adult mean
- — Length nose to tail · adult male mean
- — Length nose to tail · adult mean
- — Largest female · snout to vent
- — Largest male · snout to vent
- — Largest female · shell length
- — Largest male · shell length
- — Largest juvenile · snout to vent
- — Largest juvenile · shell length
- — Egg length
- — Egg width
- — Body mass · a typical adult
- — Longest recorded life
- — Preferred body temperature · chosen in a laboratory gradient
- — Body temperature when active · measured in the wild
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How the young develop
- — Gestation or incubation
- — Clutches in a year
- — Clutches a year · fewest
- — Clutches a year · most
- — First breeds from · youngest recorded
- — First breeds by · oldest recorded
- — Hatchling length · smallest recorded
- — Hatchling length · largest recorded
- — Age at first breeding · female
- — Mature from · youngest recorded
- — Mature by · oldest recorded
- — Size at maturity · smallest recorded
- — Size at maturity · largest recorded
- — Body temp in the wild · lowest mean recorded
- — Body temp in the wild · highest mean recorded
- — Colour on the back
- — Pattern on the back
- — Sex decided by
- — Red List criteria
- — Active season · shortest recorded
- — Active season · longest recorded
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
Others in Colubridae
Take this data
Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.
This species as JSON · the whole dataset
Cite this page
The Reptile & Amphibian Encyclopedia (2026). Helicops infrataeniatus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/helicops-infrataeniatus
@misc{helicops_infrataeniatus_2026,
title = {Helicops infrataeniatus},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/helicops-infrataeniatus}
}Sources
- Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
- Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
- Catalogue of Life (dataset 3LR), used under CC BY.