Reptilia · Squamata
Helicops polylepisGünther, 1861
Norman's Keelback
Photograph by Fábio Olmos, CC BY, via iNaturalist
A water-living, nocturnal, meat-eating snake from the Neotropic region, reaching 105 cm nose to tail.
Reptilia › Squamata › Colubridae › Helicops
- Grows to
- 1052mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Nocturnal
- Lives
- Aquatic
Longer than 74% 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
29 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
- 914mm3 ft
- Length nose to tail · greatest recorded
- 1052mm3 ft 5 in
- Body mass · greatestcomputed
- 204.4g7.2 oz
1052 mm total length (Feldman et al. 2016), "the smallest mature male measured 328 mm SVL and the smallest mature female 486 mm SVL" (Camargo et al. 2021), 66 males 328-675 mm SVL, mean 480.0 ± 75.8 mm 32 females 486-914 mm SVL, mean 638.0 ± 103.3 (Camargo et al. 2021),
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
- Nocturnal
- Where it lives
- Aquatic
- Habitat
- Forest, Wetlands
- Biome
- Tropical & Subtropical Moist Broadleaf Forests
- Region
- Neotropic
- Mainland or island
- Mainland
- Highest it lives · above sea level
- 600m
- Range size
- 6,378,830km²
Fish (Ramirez et al. 2023
Active (Glaudas et al. 2019)
Rahhal et al. 2023
Cabral et al. 2022
IUCN (0 to 600)
Breeding
- Reproduction
- Viviparous
Feldman et al. 2015, Moraes-da-Silva et al. 2022
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Günther
- Moved to another genus · since it was first described
- No
- Described in
- 1861
- Type locality
- Brazil
Keeping one
3 ft 5 in × 20.5 in × 2 ft 7 in(105 × 53 × 79 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 5 in (1052 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 Norman's 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.
22kJ per day
Worked out for an animal of 204 g, the heaviest recorded for Norman's 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
- — Female length · mean, nose to tail
- — 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
- — Hatchling length · snout to vent
- — Hatchling length · nose to tail
- — Largest juvenile · snout to vent
- — Largest juvenile · shell length
- — Egg length
- — Egg width
- — Body mass · a typical adult
- — Body mass · adult female, mean
- — Body mass at hatching
- — 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
- — Average clutch
- — Smallest clutch recorded
- — Largest clutch recorded
- — Mean clutch · smallest reported
- — Mean clutch · largest reported
- — 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
- — Lowest it lives · above sea level
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 polylepis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/helicops-polylepis
@misc{helicops_polylepis_2026,
title = {Helicops polylepis},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/helicops-polylepis}
}Sources
- Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
- Catalogue of Life (dataset 3LR), used under CC BY.
- Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.