Reptilia · Squamata
Emydocephalus ijimaeStejneger, 1898
Turtlehead Sea Snake
Photograph by Wikimedia Commons contributor, CC BY-SA, via Wikimedia Commons
A meat-eating snake from the Marine region, reaching 866 mm nose to tail.
Reptilia › Squamata › Elapidae › Emydocephalus
- Grows to
- 866mm
- greatest recorded
- Eats
- Carnivorous
- Lives
- Marine
- Weighs up to
- 199.6g
- greatest
Longer than only 48% of all elapid 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 219 to 5,710 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.
Standing in the world
- Still living
- Extant
- Conservation status
- Least Concern
- Status assessed · the year the Red List last looked
- 2009
The animal itself
- Limbs
- None
- Colour on the back
- Brown
- Venomous
- Yes
- Fangs
- At the front of the mouth
Size
- Length snout to vent · greatest recorded
- 855mm2 ft 10 in
- Length snout to vent · adult female mean
- 703mm2 ft 4 in
- Length nose to tail · greatest recorded
- 866mm2 ft 10 in
- Hatchling length · snout to vent
- 304mm12 in
- Body mass · greatestcomputed
- 199.6g7 oz
866 mm total length (Feldman et al. 2016), Wang et al. 2023 (female standard length [probably total length, unsure] 866 mm), Masunaga and Ota 2003 ("SVL… at birth is reported to range from 266 mm to 342 m", largest female 855 mm SVL, largest male 785 mm, "male and female E. ijimae attain sexual maturity at 500 mm and 550 mm SVL")
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
- Where it lives
- Marine
- Habitat
- Marine Neritic
- Active season · months of the year
- 12months
- Region
- Marine
- Mainland or island
- Marine
fishes (Wang et al. 2023)
Wang et al. 2023
Aquatic (Bars-Closel et al. 2017)
Breeding
- Reproduction
- Viviparous
- First breeds at
- 19–26months
ovoviviparous (Wang et al. 2023)
Naming and history
- Suborder
- Serpentes
- Infraorder
- Alethinophidia
- Subspecies
- No
- Described by
- Stejneger
- Moved to another genus · since it was first described
- No
- Described in
- 1898
- Type locality
- Japan
Keeping one
2 ft 10 in × 17 in × 2 ft 2 in(87 × 43 × 65 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 10 in (866 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 Turtlehead Sea 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.
22kJ per day
Worked out for an animal of 200 g, the heaviest recorded for Turtlehead Sea 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 · 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
- — Active
- — 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
- — 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
- — Pattern on the back
- — Pupil
- — Sex decided by
- — Population trend
- — Red List criteria
- — Biome
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
- — Lowest it lives · above sea level
- — Highest it lives · above sea level
- — Range size
Others in Elapidae
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). Emydocephalus ijimae. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/emydocephalus-ijimae
@misc{emydocephalus_ijimae_2026,
title = {Emydocephalus ijimae},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/emydocephalus-ijimae}
}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.