Reptilia · Squamata
Homalopsis mereljcoxiMurphy, Voris, Murthy, Traub, Cumberbatch, 2012
Jack’s Water Snake
Photograph by Theo Busschau, CC BY, via iNaturalist
A water-living, nocturnal, meat-eating snake from the Oriental region, reaching 973 mm snout to vent.
Reptilia › Squamata › Homalopsidae › Homalopsis
- Grows to
- 973mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Nocturnal
- Lives
- Aquatic
Longer than 96% 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 115 to 973 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
25 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
The animal itself
- Limbs
- None
- Venomous
- Yes
- Fangs
- At the back of the mouth
Size
- Length snout to vent · greatest recorded
- 973mm3 ft 2 in
- Female length · mean, nose to tail
- 809mm2 ft 8 in
- Hatchling length · nose to tail
- 342mm13.5 in
- Body mass · greatestcomputed
- 1370.4g3 lb
973 mm SVL (Feldman et al. 2016), Cox et al. 2012 (mean TL 879 mm in males, 809 mm in females, neonates 325-360 mm at birth - looks large)
largely converted from length by allometry in the source
How it lives
- Diet
- Carnivorous
- Active
- Nocturnal
- Where it lives
- Aquatic
- Biome
- Tropical & Subtropical Dry Broadleaf Forests
- Region
- Oriental
- Mainland or island
- Mainland
- Range size
- 10,607km²
primarily fish and frogs (Cox et al. 2012)
Cox et al. 2012
"highly aquatic" (Cox et al. 2012)
Breeding
- Reproduction
- Viviparous
- Average clutch
- 23
- Eggs or young per clutch
- 13–33eggs
Feldman et al. 2015, Cox et al. 2012
midpoint of the reported range — Meiri, 2024, Glob. Ecol. Biogeogr., 33:e13812
13-33 (Cox et al. 2012)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Murphy, Voris, Murthy, Traub, Cumberbatch
- Moved to another genus · since it was first described
- No
- Described in
- 2012
- Type locality
- Thailand
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.
120kJ per day
Worked out for an animal of 1,370 g, the heaviest recorded for Jack’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 female mean
- — Length snout to vent · adult male mean
- — Length snout to vent · adult mean
- — Length nose to tail · greatest recorded
- — 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
- — 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
- — 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
- — Pupil
- — Sex decided by
- — Conservation status
- — Status assessed · the year the Red List last looked
- — Population trend
- — Red List criteria
- — Active season · shortest recorded
- — Active season · longest recorded
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Habitat
- — Active in
- — Lowest it lives · above sea level
- — Highest it lives · above sea level
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). Homalopsis mereljcoxi. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/homalopsis-mereljcoxi
@misc{homalopsis_mereljcoxi_2026,
title = {Homalopsis mereljcoxi},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/homalopsis-mereljcoxi}
}Sources
- Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
- Moura, M. R. et al. TetrapodTraits: a database of 33,281 tetrapod species. Used under CC BY 4.0. Observed values only; this encyclopedia does not publish its imputed predictions.
- 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.