The Marine Iguana is a species of iguana that is native to the Galápagos Islands. This is the only place in the world where these lizards can be found.
Males are expert divers and will dive to the bottom of the ocean to feed off of algea while females and juveniles will forage for food at low tide.
The Marine Iguana is the only extant lizards that spend the majority of their time in a marine environment.
Marine Iguana Taxonomy
In the Animal Kingdom, Taxonomy is used as the science and practice of classifying different species and sub-species based on their biological and genetic makeup.
Family
The Marine Iguana belongs to the Iguanidae family of Lizards. This essentially means that the lizard is an Iguana.
Some species of Iguana are common in the pet trade such as the Green Iguana and the Fijian Iguana but there are actually 8 different genera and around 35 different species in the family.
This number can vary greatly depending on what literature you read. The Iguanidae family is heavily debated and changes all the time, with many groups of lizards sometimes classed under sub-families of Iguanidae.
If you were to include all of these ‘sub-families’ as genuine, there would be around 1,000 species in the family.
However, most experts agree that this isn’t the case and classify all of these lizards under the same sub-order.
As a result, it can be taken that all of these species can be considered part of the Iguana complex, but only the species in the family Iguanidae can be considered ‘True Iguanas’.
The species in this family can be quite diverse and live very different lifestyles. Some species are terrestrial, some are arboreal and others can be rock-dwelling lizards.
Genus
The genus that the Marine Iguana belongs to is called Amblyrhynchus. AS this is a very unique species, it is the only one in the genus.
In fact, this genus was created for the sole purpose of housing the Marine Iguana.
Species
The scientific name for the Marine Iguana is Amblyrhynchus cristatus and there are currently seven recognised sub-species.
The species was first described in 1825 by an English zoologist named Thomas Hornsey Bell.
Some of the sub-species include the Isabela Marine Iguana, the Santa Cruz Marine Iguana and the Pinta Marine Iguana.
Marine Iguana Description
The Marine Iguana is usually black or grey in color. Adult males can change to a more vibrant green or red color during the breeding season.
As these lizards spend the vast amount of their time out in the open exposed to the sun, their dark skin pigment helps to shield them from the sun’s ultraviolet rays.
Their dark coloration also helps them absorb the heat from the sun and warm their bodies. This is particularly important as they can lose a lot of heat when submerged.
The Marine Iguana has a particularly long tail which they use to help propel them through the water.
Like most Iguanas, they have large ridges running down the centre of their back. These ridges can helps regulate body temperature as the lizard basks in the sun.
Natural Habitat and Distribution
The Marine Iguana is only found on a group of islands known as the Galapagos Island. This archipelago of volcanic islands is located in the Pacific Island off the coast of South America.
These islands are located around 900km off the coast of Ecuador and are belonged to the Republic of Ecuador.
Many of the islands have steep rock cliffs, low rock ledges and intertidal flats which are important for these lizards as they need access to both the sea for hunting and sandy areas for laying eggs.
The Marine Iguana is only found across many of the islands that make up the Galapagos. However, many of these islands are home to specific sub-species.
For example, the Santa Cruz Marine Iguana is mainly found on the island of Santa Cruz while the Española Marine Iguana is mainly found on the islands of Española and Floreana.
Behaviour
The Marine Iguana is a diurnal species of lizard, meaning they are mostly active during the day and sleep during the night.
They will spend much of the day basking on rocks before diving into the sea in search of food.
This basking behaviour is vital for these lizards as they need to raise their body temperature and get warm enough to be able to function properly.
The heat of the sun, as well as the radiated heat from the rock help to quickly heat the iguana back up after the have spent time hunting in water.
These lizards live in groups or colonies and can be very territorial to outsiders. After emerging from the water, they become quite sluggish as their body temperature drops significantly.
At this time, they are much more prone to predators so revert to aggressive ‘bluffs’ if they feel threatened.