Reptilia · Squamata
Rhabdophis helleriSchmidt, 1925
Heller’s Red-necked Keelback
Photograph by Lawrence Hylton, CC BY, via iNaturalist
A day-active, meat-eating snake from the Oriental region, reaching 130 cm nose to tail.
Reptilia › Squamata › Colubridae › Rhabdophis
- Grows to
- 1300mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Diurnal
- Lives
- Semi-aquatic
Longer than 83% 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
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
- Colour on the back
- Green
Size
- Length snout to vent · greatest recorded
- 865mm2 ft 10 in
- Length nose to tail · greatest recorded
- 1300mm4 ft 3 in
- Female length · mean, nose to tail
- 826mm2 ft 9 in
- Hatchling length · snout to vent
- 131mm5.25 in
- Hatchling length · nose to tail
- 173.5mm6.75 in
- Body mass · greatestcomputed
- 319.9g11.3 oz
Das et al. 2021 (max 785 mm SVL, 1012 mm Total, means for 4 females 656.8 and 826 mm), Lalmuansanga et al. 2021 (817 mm female, SVL, 12 hatchlings SVL = 129.67 mm (127–135 mm), tail length = 42.35 mm (40–45 mm).), David and Vogel 2021: "The longest examined specimen is 1,107 mm long (SVL 865 mm; TaL 242 mm; specimen NHMUK 1926.3.17.1, female). The longest male in our sample is 999 mm long (SVL 723 mm, TaL 276 mm; NMW 22468:1). According to the literature, R. helleri may reach a total length of 130 centimetres. This species is much larger than R. siamensis. In our sample of 51 specimens, 17 are over 800 mm in TL and even six are over 900 mm in total length.", Wang et al. 2023 (female standard length [probably total length, unsure] 180~1135 mm), Wang et al. 2023 (max total length 1135 mm), Cox et al. 2012 (max 1300 mm, hatchlings 130-190 mm)
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
- Diurnal
- Where it lives
- Semi-aquatic
- Region
- Oriental
- Mainland or island
- Mainland
- Highest it lives · above sea level
- 2000m
frogs, toads (Wang et al. 2023) and fish (Cox et al. 2012)
Wang et al. 2023
(Feldman 2015 for Rhabdophis subminiatus), Diurnal (Cox et al. 2012)
Terrestrial (Wang et al. 2023), terrestrial and semi-aquatic (Cox et al. 20120
max 2000 (Cox et al. 2012)
Breeding
- Reproduction
- Oviparous
- Eggs or young per clutch
- 5–17eggs
Jensen et al. 2008, Cox et al. 2012
5-17 (Whitaker and Captain 2004), 15 (Lalmuansanga et al. 2021; n = 1), max 14 (Cox et al. 2012)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Schmidt
- Moved to another genus · since it was first described
- Yes
- Described in
- 1925
- Type locality
- China
Keeping one
4 ft 3 in × 2 ft 2 in × 3 ft 2 in(130 × 65 × 98 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 4 ft 3 in (1300 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 Heller’s 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.
33kJ per day
Worked out for an animal of 320 g, the heaviest recorded for Heller’s 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
- — 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
- — 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
- — 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
- — Habitat
- — Active in
- — Lowest it lives · above sea level
- — 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 helleri. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/rhabdophis-helleri
@misc{rhabdophis_helleri_2026,
title = {Rhabdophis helleri},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/rhabdophis-helleri}
}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.