Marine iguana

Amblyrhynchus cristatus Bell, 1825

The marine iguana (Amblyrhynchus cristatus) is a lizard in the family Iguanidae, order Squamata, within the reptiles. It is a medium-sized animal by adult body mass, with a representative adult weight of 1.82 kg, a reported range from 1.4 to 2.2 kg, and a body length of 42.7 cm.

Photo: Sodacan · CC BY-SA 4.0 · Wikimedia Commons

Quick facts about the marine iguana

It has 1 clutch per year with 2.4 eggs or young per clutch, and eggs incubate for 103.5 days. The IUCN Red List classifies the marine iguana as Vulnerable, a threatened category, and its lifespan is given as 6.4 years.

Weight: 1.41 kg – 3.6 kgsrc for Weight
Length: 32 cm – 42.7 cmsrc for Length
Lifespan: 6.4 yearssrc for Lifespan
Diet: Herbivoresrc for Diet
Longest recorded lifespan: 28 years
Main food: Not recorded
Habitat: marinesrc for Habitat
Egg incubation: 104 dayssrc for Egg incubation
Young per litter or clutch: 1 – 6src for Young per litter or clutch
Age at maturity: 3.42 yearssrc for Age at maturity
Litters or clutches a year: 0.5 – 1src for Litters or clutches a year
Reproduction: Eggssrc for Reproduction
Active: By day (diurnal)src for Active
Lifestyle: Marinesrc for Lifestyle
Conservation status: Vulnerable (IUCN)src for Conservation status
Countries on record: Not recorded

How big is the marine iguana?

At 42.7 cm, the recorded maximum length of the marine iguana is about 25% of the height of an adult human (1.7 m, a fixed reference used for scale).

Photos of the marine iguana

Only freely licensed photos are shown. Each carries its creator and licence.

Marine iguana (Amblyrhynchus cristatus) — Diego Delso · CC BY-SA 4.0 · Wikimedia Commons

1 more photo exists under a licence we cannot display: view at source.

Where does the marine iguana live?

Not recorded

What is the marine iguana?

Quoted from WikipediaCC BY-SA 4.0

The marine iguana (Amblyrhynchus cristatus), also known as the sea iguana, saltwater iguana, or Galápagos marine iguana, is a species of iguana found only on the Galápagos Islands (Ecuador). Unique among modern lizards, it is a marine reptile that has the ability to forage in the sea for algae, which make up almost all of its diet. Marine iguanas are the only extant lizard that spends time in a marine environment. Large males are able to dive to find this food source, while females and smaller males feed during low tide in the intertidal zone. They mainly live in colonies on rocky shores where they bask after visiting the relatively cold water or intertidal zone, but can also be seen in marshes, mangrove swamps and beaches. Large males defend territories for a short period, but smaller males have other breeding strategies. After mating, the female digs a nest hole in the soil where she lays her eggs, leaving them to hatch on their own a few months later.
Marine iguanas vary in appearance between the different islands and several subspecies are recognized. Although relatively large numbers remain and it is locally abundant, this protected species is considered threatened, primarily from El Niño cycles, introduced predators and chance events like oil spills.

From the Wikipedia article “Marine iguana” (en.wikipedia.org/w/index.php?title=Marine_iguana&oldid=1380695076), by Wikipedia contributors, licensed under CC BY-SA 4.0 (creativecommons.org/licenses/by-sa/4.0). This block is kept separate from our own text.

Is the marine iguana endangered?

The marine iguana is listed as Vulnerable on the IUCN Red List: it faces a high risk of extinction in the wild.

LCLeast Concern
NTNear Threatened
VUVulnerable
ENEndangered
CRCritically Endangered
EWExtinct in the Wild
EXExtinct

Category via Wikidata (CC0). Find the full assessment on the IUCN Red List. See all Vulnerable species.

How is the marine iguana classified?

kingdomAnimalia
phylumChordata
classReptilia
orderSquamata
familyIguanidae
genusAmblyrhynchus
SpeciesAmblyrhynchus cristatus Bell, 1825

Synonyms Amblyrhincus demarlii, Amblyrhynchus cristatus albemarlensis, Amblyrhynchus nanus

Other names and names in other languages (63)

Fernandina marine iguanaEnglish
Fernandina marine iguanaEnglish
Galapagos marine iguanaEnglish
Galapagos marine iguanaEnglish
Galapagos marine iguanaEnglish
Galápagos marine iguanaEnglish
Galápagos marine iguanaEnglish
Sea iguanaEnglish
Sea iguanaEnglish
SeelikkewaanAfrikaans
إغوانة بحريةArabic
Марская яшчаркаBelarusian
Igwan-morBreton
Тангыж игуанаMari
leguán mořskýCzech
havleguanDanish
MeerechseGerman
Θαλάσσιο ΙγκουάναGreek
MarigvanoEsperanto
Iguana MarinaSpanish
ایگوانای دریاییPersian
MerileguaaniFinnish
AmblyrhyncheFrench
Amblyrhynche à crêteFrench
Iguane marinFrench
Iguane marin des GalapagosFrench
Ioguána mara oileáin GalápagosIrish
Iguana mariñaGalician
איגואנה ימיתHebrew
Tengeri leguánHungarian
Ծովային իգուանաArmenian
Iguana lautIndonesian
Iguana di mareItalian
Iguana marina delle GalápagosItalian
ウミイグアナJapanese
ზღვის ხვლიკიGeorgian
바다이구아나Korean
Jūrinė iguanaLithuanian
морска игуанаMacedonian
Naʼashǫ́ʼiitsoh naʼałkǫ́ʼígííNavajo
HaviguanNorwegian Bokmål
ZeeleguaanDutch
legwan morskiPolish
سمندری ایگواناWestern Panjabi
Iguana-marinhaPortuguese
Iguană marinăRomanian
Морская игуанаRussian
Morska iguanaSerbian
See-LeeguoanSaterland Frisian
HavsleguanSwedish
கடற்பேரோந்திTamil
อิกัวนาทะเลThai
อีกัวนาทะเลThai
deniz iguanasiTurkish
Морська ігуанаUkrainian
Pinta Marine Iguanaroot
Española Marine Iguanaroot
Genovesa Marine Iguanaroot
Isabela Marine Iguanaroot
San Cristóbal Marine Iguanaroot
Santa Cruz Marine Iguanaroot
Kỳ nhông biểnVietnamese
海鬣蜥Chinese

Catalogue of Life Wikipedia iNaturalist ITIS Wikidata WoRMS IUCN Red List

Relatives of the marine iguana

Other species in the same family Iguanidae.

Green iguana

Iguana iguana

Iguanidae

Galápagos land iguana

Conolophus subcristatus

Iguanidae

Blue iguana

Cyclura lewisi

IguanidaeNo free photo yet

Black iguana

Ctenosaura similis

IguanidaeNo free photo yet

Horned iguana

Cyclura cornuta

IguanidaeNo free photo yet

Desert iguana

Dipsosaurus dorsalis

IguanidaeNo free photo yet

CompareMarine iguana vs Green iguana Marine iguana vs Galápagos land iguana Marine iguana vs Blue iguana Marine iguana vs Black iguana

Common questions

Each answer is written from the sourced facts on this page, and only where they hold the answer.

What kind of animal is the marine iguana?

The marine iguana is a lizard, a reptile in the family Iguanidae and the order Squamata.

How heavy is a marine iguana?

An adult marine iguana weighs 1.82 kg as a representative value, with reported weights from 1.4 to 2.2 kg.

How long is a marine iguana?

The marine iguana has a representative body length of 42.7 cm.

Is the marine iguana endangered?

The marine iguana is listed as Vulnerable on the IUCN Red List, which is a threatened category.

How long does a marine iguana live?

The lifespan of the marine iguana is given as 6.4 years.

How many eggs does a marine iguana lay?

The marine iguana has 2.4 eggs or young per clutch and 1 clutch per year. Eggs incubate for 103.5 days.

Who named the marine iguana?

The marine iguana, Amblyrhynchus cristatus, was named by Bell, 1825.

Sources and how to cite this page

Data as of 2026-11-11. How this page is put together.

An amniote life-history database to perform comparative analyses with birds, mammals, and reptiles · CC0 1.0 · E096-269
Myhrvold, N.P., Baldridge, E., Chan, B., Sivam, D., Freeman, D.L. & Ernest, S.K.M. (2015) An amniote life-history database to perform comparative analyses with birds, mammals, and reptiles. Ecology 96: 3109. https://doi.org/10.1890/15-0846R.1. Data: https://doi.org/10.6084/m9.figshare.3563457.v1
Catalogue of Life eXtended Release · CC BY 4.0 · 2026-10-16 XR
Catalogue of Life (2026). Catalogue of Life eXtended Release, version 2026-10-16 XR. Catalogue of Life Foundation, Amsterdam, Netherlands. https://doi.org/10.48580/dgzlf
Wikimedia Commons · per file (CC0 / public domain / CC BY green, CC BY-SA amber, anything else not displayed) · 2026-11-11
Wikimedia Commons contributors. Wikimedia Commons. https://commons.wikimedia.org (each file credited to its author under its own licence).
ReptTraits: a comprehensive dataset of ecological traits in reptiles · CC BY 4.0 · v1-2
Oskyrko, O., Mi, C., Meiri, S. et al. (2024) ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data 11: 243. https://doi.org/10.1038/s41597-024-03079-5. Data: https://doi.org/10.6084/m9.figshare.24572683.v4
SquamBase 1.0 - a dataset of squamate species traits · CC0 1.0 · 1.0-dryad-v5
Meiri, S. (2024) SquamBase - a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography 33(4): e13812. https://doi.org/10.1111/geb.13812. Data: https://doi.org/10.5061/dryad.76hdr7t3b
Wikidata · CC0 1.0 · 2026-11-11
Wikidata contributors. Wikidata. https://www.wikidata.org (data retrieved via the Wikidata Query Service).
Wikipedia (English) · CC BY-SA 4.0 · 2026-11-11
Wikipedia contributors. Wikipedia, The Free Encyclopedia. https://en.wikipedia.org (text under CC BY-SA 4.0; each block names its article and revision).

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<iframe src="https://creaturedata.com/embed/animals/marine-iguana" title="Marine iguana on CreatureData" width="360" height="520" style="border:0;max-width:100%" loading="lazy"></iframe>

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APA

CreatureData. (2026). Marine iguana (Amblyrhynchus cristatus). Retrieved from https://creaturedata.com/animals/marine-iguana

MLA

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BibTeX

@misc{marine_iguana_2026,
  title = {Marine iguana (Amblyrhynchus cristatus)},
  author = {{CreatureData}},
  year = {2026},
  url = {https://creaturedata.com/animals/marine-iguana},
  note = {Data as of 2026-11-11}
}