Reptilia · Squamata
Trimerodytes percarinatusBoulenger, 1899
Olive Keelback
Photograph by Lawrence Hylton, CC BY, via iNaturalist
An active by day or night, meat-eating snake from the Oriental region, reaching 116 cm nose to tail.
Also called Eastern Water Snake, Olive Annulate Keelback.
Once published as Sinonatrix percarinata — those names reach this page.
Reptilia › Squamata › Colubridae › Trimerodytes
- Grows to
- 1158.5mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Cathemeral
- Lives
- Semi-aquatic
Longer than 78% 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
32 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
- 2011
- Population trend
- Stable
The animal itself
- Limbs
- None
- Colour on the back
- Brown, Gray
- Pupil
- Round
- Fangs
- At the back of the mouth
Size
- Length nose to tail · greatest recorded
- 1158.5mm3 ft 10 in
- Female length · mean, nose to tail
- 940mm3 ft 1 in
- Body mass · greatestcomputed
- 770.2g1.7 lb
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
- Semi-aquatic
- Habitat
- Forest, Wetlands
- Biome
- Tropical & Subtropical Moist Broadleaf Forests
- Region
- Oriental
- Mainland or island
- Mainland
- Elevation · above sea level
- 300–2000m
- Range size
- 2,881,319km²
fishes, frogs, tadpoles, crayfishes, shrimps (Wang et al. 2023), amphibians and crustaceans (Cox et al. 2012)
Wang et al. 2023
Diurnal (Feldman 2015), afternoon (Pham et al. 2022, n = 1), nocturnal (Cox et al. 2012)
Aquatic (Feldman 2015, Deepak et al. 2022), near a stream (Pham et al. 2022, n = 1), semi aquatic (Cox et al. 2012)
300-2000 (Feldman 2015), 500-1600 (Cox et al. 2012)
Breeding
- Reproduction
- Oviparous
- Sex decided by
- Genes, ZW/ZZ
- Average clutch
- 10eggs
- Eggs or young per clutch
- 4–12eggs
Feldman et al. 2015, Cox et al. 2012
mean=8 (Feldman 2015), 4-12 (Cox et al. 2012)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- Trimerodytes percarinatus percarinatus (BOULENGER 1899) Trimerodytes percarinatus suriki (MAKI 1931)
- Described by
- Boulenger
- Moved to another genus · since it was first described
- Yes
- Described in
- 1899
- Type locality
- Burma
Keeping one
3 ft 10 in × 23 in × 2 ft 10 in(116 × 58 × 87 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.
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 10 in (1158.5 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 Olive 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.
72kJ per day
Worked out for an animal of 770 g, the heaviest recorded for Olive 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 · greatest recorded
- — 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
- — 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
- — 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
- — Venomous
- — Body temp in the wild · lowest mean recorded
- — Body temp in the wild · highest mean recorded
- — Pattern on the back
- — 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). Trimerodytes percarinatus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/trimerodytes-percarinatus
@misc{trimerodytes_percarinatus_2026,
title = {Trimerodytes percarinatus},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/trimerodytes-percarinatus}
}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.