Reptilia · Squamata
Rhabdophis siamensisMell, 1931
Siamese red-necked keelback
Photograph by Noah Kirkland, CC BY, via iNaturalist
A day-active, meat-eating snake from the Oriental region, reaching 772 mm nose to tail.
Reptilia › Squamata › Colubridae › Rhabdophis
- Grows to
- 772mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Diurnal
- Weighs up to
- 106.4g
- greatest
Longer than 58% 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
20 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
- Colour on the back
- Gray
Size
- Length snout to vent · greatest recorded
- 600mm23.5 in
- Length nose to tail · greatest recorded
- 772mm2 ft 6 in
- Body mass · greatestcomputed
- 106.4g3.8 oz
David and Vogel 2021 ("The maximal total length in our sample is 772 mm (SVL 569 mm; TaL 203 mm; specimen MNHN-RA 1974.1290, female). The longest known male in our sample is 737 mm long (SVL 528 mm, TaL 209 mm; ZMB 263010). This species may reach greater total lengths as we have examined a specimen with a SVL > 600 mm. In our sample of 79 specimens, 18 have a total length over 600 mm and only 5 are over 700 mm long."), but if this is what was regarded as R. subminiatus, Wang et al. 2023 (female standard length [probably total length, unsure] 772 mm)
snakes only in this source
computed from length by a family-level allometric equation, not weighed
How it lives
- Diet
- Carnivorous
- Active
- Diurnal
- Habitat
- Forest, Grassland, Shrubland
- Region
- Oriental
- Mainland or island
- Mainland
- Elevation · above sea level
- 30m
anurans (Vuong et al. 2023b)
(Feldman 2015 for Rhabdophis subminiatus), Diurnal (Vuong et al. 2023b)
Vuong et al. 2023b
Breeding
- Reproduction
- Oviparous
Jensen et al. 2008
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Mell
- Moved to another genus · since it was first described
- Yes
- Described in
- 1931
- Type locality
- Thailand
Keeping one
2 ft 6 in × 15 in × 23 in(77 × 39 × 58 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 2 ft 6 in (772 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 Siamese red-necked 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.
12kJ per day
Worked out for an animal of 106 g, the heaviest recorded for Siamese red-necked 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 it hunts
- — Where it lives
- — 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
- — Venomous
- — Fangs
- — Body temp in the wild · lowest mean recorded
- — Body temp in the wild · highest mean recorded
- — Pattern on the back
- — Pupil
- — Sex decided by
- — Conservation status
- — Status assessed · the year the Red List last looked
- — Population trend
- — Red List criteria
- — Biome
- — Active season · shortest recorded
- — Active season · longest recorded
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
- — Range size
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). Rhabdophis siamensis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/rhabdophis-siamensis
@misc{rhabdophis_siamensis_2026,
title = {Rhabdophis siamensis},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/rhabdophis-siamensis}
}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.