Reptilia · Squamata
Hydrosaurus amboinensisSchlosser, 1768
(Amboina) Sailfin Lizard
Photograph by Igor Balashov, CC BY, via iNaturalist
A day-active, plant-eating lizard from the Australo-Pacific region, reaching 350 mm snout to vent.
Reptilia › Squamata › Agamidae › Hydrosaurus
- Grows to
- 350mm
- greatest recorded
- Eats
- Herbivorous
- Active
- Diurnal
- Lives up to
- 24.4years
Longer than 99% of all agamids 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 32 to 418 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
33 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
- 2019
The animal itself
- Limbs
- Four legs
- Venomous
- No
- Fangs
- None
- Longest recorded life
- 24.4years
Carey and Judge 2000, De Magalhaes & Costa 2009, Honegger 1969, Slavens and Slavens 1999: 24.4; Snider and Bowler 1992: 3.5
Size
- Length snout to vent · greatest recorded
- 350mm14 in
- Length snout to vent · adult female mean
- 250mm9.75 in
- Body mass · greatestcomputed
- 1634.3g3.6 lb
Shai Meiri, unpublished; Glasser-Trobisch and Trobisch 2021 (female 250 mm, n = 1)
computed from length by a family-level allometric equation, not weighed
How it lives
- Diet
- Herbivorous
- Active
- Diurnal
- Where it lives
- Semi-aquatic
- Habitat
- Forest, Wetlands
- Biome
- Tropical & Subtropical Moist Broadleaf Forests
- Active season · months of the year
- 12months
- Region
- Australo-Pacific
- Mainland or island
- Found only on islands
- Highest it lives · above sea level
- 800m
- Range size
- 165,540km²
Omnivorous (e.g., Zoffer 1996)/ mainly herbivorous but also take insects - adults eat leaves, juveniles eat seeds, (Whitten and Henderson 2001)
e.g., Jenssen and Sy 2022
semi aquatic (Bauer and Jackman 2008, Glasser-Trobisch and Trobisch 2021) and arboreal
0 (Jenssen and Sy 2022)
Breeding
- Reproduction
- Oviparous
- Average clutch
- 7.5eggs
- Eggs or young per clutch
- 3–9eggs
- Mean clutch
- 7–8eggs
- Clutches in a year
- 6per year
- Clutches a year
- 6per year
Naming and history
- Suborder
- Sauria
- Infraorder
- Acrodontia
- Subspecies
- No
- Described by
- Schlosser
- Moved to another genus · since it was first described
- Yes
- Described in
- 1768
- Type locality
- Indonesia
Keeping one
4 ft 7 in × 4 ft 7 in × 2 ft 10 in(140 × 140 × 88 cm)
Minimum length × width × height, for one animal. Bigger is always better.
The standard sizes ground-dwelling species at 4 × 4 × 2.5 times snout-vent length.
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 snout-vent length of 14 in (350 mm), at 4 × 4 × 2.5 times it, following the German federal welfare standard — how this is worked out.
No preferred body temperature has been recorded for (Amboina) Sailfin Lizard. Rather than repeat a number from a care sheet, this page leaves it out.
Feeding
Prey size does not apply. A herbivore's diet is judged on fibre, on the ratio of calcium to phosphorus, and on avoiding plants high in oxalates.
The animal does not take prey items. This is established practice, not a measurement.
141kJ per day
Worked out for an animal of 1,634 g, the heaviest recorded for (Amboina) Sailfin Lizard — 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
- — Length nose to tail · greatest recorded
- — 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
- — 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
- — 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
- — Population trend
- — Red List criteria
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
- — Lowest it lives · above sea level
Others in Agamidae
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). Hydrosaurus amboinensis. Retrieved 2026-09-09, from https://www.allanglescreatures.com/species/hydrosaurus-amboinensis
@misc{hydrosaurus_amboinensis_2026,
title = {Hydrosaurus amboinensis},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/hydrosaurus-amboinensis}
}Sources
- Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
- Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
- Catalogue of Life (dataset 3LR), used under CC BY.