Reptilia · Squamata
Hypsiscopus matannensisBoulenger, 1897
Boulenger's Water Snake
No photograph of this species exists under a license anyone may reuse. It gets the same page regardless.
A water-living, nocturnal, meat-eating snake from the Oriental region, reaching 563 mm nose to tail.
Reptilia › Squamata › Homalopsidae › Hypsiscopus
- Grows to
- 563mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Nocturnal
- Lives
- Aquatic
Longer than only 35% of all species in Homalopsidae 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 128 to 1,400 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
28 sourced facts, each taken from a named scientific dataset. How to read these.
Cited from a dataset unless a row is marked otherwise.
Two of these figures disagree
Length snout to vent (greatest recorded) is given as 640, and Length nose to tail (greatest recorded) as 563 — but snout to vent is part of the animal's total length, not more than it. They come from different sources and both are shown exactly as those sources give them.
Standing in the world
- Still living
- Extant
- Conservation status
- Data Deficient
- Status assessed · the year the Red List last looked
- 2019
The animal itself
- Limbs
- None
- Pupil
- Vertical slit
- Venomous
- Yes
- Fangs
- At the back of the mouth
Size
- Length snout to vent · adult female mean
- 417mm16.5 in
- Body mass · greatestcomputed
- 83.48g2.9 oz
- Length snout to vent · greatest recordeddisputed
- 640mm2 ft 1 in
- Length nose to tail · greatest recordeddisputed
- 563mm22 in
563 mm total length (Feldman et al. 2016), Hamidy et al. 2023 (8 males, 370–640 mm SVL, 5 females 270–564 mm SVL - probably with juveniles)
largely converted from length by allometry in the source
How it lives
- Dietcomputed
- Carnivorous
- Active
- Nocturnal
- Where it lives
- Aquatic
- Habitat
- Wetlands
- Biome
- Tropical & Subtropical Moist Broadleaf Forests
- Region
- Oriental
- Mainland or island
- Found only on islands
- Elevation · above sea level
- 21–981m
- Range size
- 5946km²
no actual data but can be imputed as carnivorous like all snakes
Feldman 2015
Breeding
- Reproduction
- Viviparous
Feldman et al. 2015
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Boulenger
- Moved to another genus · since it was first described
- Yes
- Described in
- 1897
- Type locality
- Indonesia
Keeping one
22 in × 11 in × 16.5 in(56 × 28 × 42 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 22 in (563 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 Boulenger's Water Snake. 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.
10kJ per day
Worked out for an animal of 83 g, the heaviest recorded for Boulenger's Water Snake — 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 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 it hunts
- — 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
- — Population trend
- — 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 Homalopsidae
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). Hypsiscopus matannensis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/hypsiscopus-matannensis
@misc{hypsiscopus_matannensis_2026,
title = {Hypsiscopus matannensis},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/hypsiscopus-matannensis}
}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.