“Miniature-dinosaur-looking” Iguanas belong to the lizard family Iguanidae. Classified as herbivorous reptiles, these slithery creatures encompass a wide range of lizard species, including the well-known green iguana (Iguana iguana) and the marine iguana (Amblyrhynchus cristatus). They are commonly native to northern Mexico, Central America, the Caribbean Islands, and southern Brazil.

Predominantly terrestrial, marine iguanas are restricted to the Galapagos Islands. Their habitats include sandy beaches and rocky shores. Belonging to the Squamata order (snakes, lizards, and relatives), this species is the only lizard on the planet to spend time in the ocean. With an inclination to an island lifestyle, marine iguanas are observed to feed in shallow marine waters but are often found basking in the sun, along the shore.

Meet the Marine Iguana Subspecies

A team of European and Latin American scientists from the TU Braunschweig in Germany has discovered five previously not listed subspecies of the marine iguanas. Among them is the Amblyrhynchus cristatus godzilla, which was named after the fictional saurian monster Godzilla.

The researchers now have revised the taxonomy of this emblematic species on the Galapagos and distinguished 11 distinct taxa of marine iguanas, classified as subspecies. The new taxonomy permits a better protection of the marine iguanas. The research results were recently published in the Zoological Journal of the Linnean Society.

“Bad taxonomy can kill” becomes a major theme for scientists and conservationists with respect to threatened species. It means the loss of genetic diversity of a species by unknown and non-classified differences at the level of populations within one species.

“We were really surprised to see that world’s leading conservation organizations, such as the International Union for Conservation of Nature (IUCN), relied on a completely outdated taxonomy for such a unique and threatened species as the marine iguana” explained Steinfartz.

In a study, published in the Zoological Journal of the Linnean Society, the researchers now have revised the taxonomy of this emblematic species. Based on an intensive study of genomic and morphological characters, the scientists now distinguish 11 distinct taxa of marine iguanas, classified as subspecies. Five of these subspecies are newly discovered and described in their study.

Dr. Aurelien Miralles, the leading scientist of this study from the Natural History Museum in Paris (France) states: “It was astonishing that upon closer inspection, most of the populations from different islands had significant differences in morphology and coloration when compared to their neighbors on other islands.” He adds: “Certainly Charles Darwin would have surely held these lizards in higher regard, if he had known how well their divergence matches the expectations of evolutionary theory.”

The most remarkable of the newly discovered taxa is the cryptic and highly threatened subspecies found only in the northeast of the oldest island of the archipelago, San Cristóbal. For this outstanding population, the scientists have dubbed this subspecies “the Godzilla marine iguana”(Amblyrhynchus cristatus godzilla), in honor of the fictional saurian monster Godzilla, which was in turn originally inspired by marine iguanas. As a species, marine iguanas are threatened.

Many island populations are endangered by predation of feral animals, marine pollution and encroachment of urban developments, such as the building of new hotel complexes at the shore of the island of San Cristóbal.

The new system of subspecies outlined by this study will serve as a basis for conservation management units, which will enable managers to fully safeguard vital genetic diversity of distinct populations, which should ultimately aid the long-term survival of these unique creatures. Steinfartz sums up: “We hope that the new taxonomy will serve as a better protection of this unique species.”

Reference
Miralles Aurélien, MacLeod Amy, Rodríguez Ariel, Ibáñez Alejandro, Jiménez-Uzcategui Gustavo , Quezada Galo, Vences Miguel, Steinfartz Sebastian. Shedding light on the Imps of Darkness: An integrative taxonomic revision of the Galapagos marine Iguanas (genus Amblyrhynchus).

Contact
Dr. Sebastian Steinfartz
Technische Universität Braunschweig
Division of Evolutionary Biology
Zoological Institute
Mendelssohnstraße 4
38106 Braunschweig, Germany
Phone: +49 531 391-2393
Email: s.steinfartz@tu-braunschweig.de

www.zoologie.tu-bs.de/index.php/en/evolutionsbiologie 
https://magazin.tu-braunschweig.de/pi-post/godzilla-meerechse-auf-den-galapagos-…

Are Iguana Bites Fatal?

Iguanas are known to have around 80 to 120 serrated teeth formed in four equal quadrants. Although it possesses venom glands, an iguana’s bite may not be venomous. However, an iguana’s bite can cause a significant skin gash. Male iguanas become especially aggressive and territorial at the end of the summer, marking their mating season.

Additionally, these lizard species use their tails as defense mechanisms against predators, including humans, if threatened. Further caution is advised because iguanas can carry Salmonella bacteria, which may cause health issues in humans. 

What are the Threats and Predators Marine Iguanas Face?

As per the last assessment in 2019, marine iguanas are listed as Vulnerable on the IUCN Red. Hawks, herons, and endemic racer snakes prey on juvenile marine iguanas. Additionally, cats and dogs brought to the islands have posed a serious threat as land predators, while the shark (Heller, 1903) takes the spot of their main marine predator. Adult males rarely find themselves prey due to their anatomy, but adult females might be susceptible to hawks during reproduction.

A Unique Aquatic Species—Marine Iguanas

The marine iguana, with its unique adaptation to ocean life, faces multiple threats, from invasive predators to habitat destruction. Recent research has led to a revised taxonomy, identifying 11 distinct subspecies, including the newly discovered “Godzilla” marine iguana, which could enhance conservation efforts. While challenges remain, the updated classification of the marine iguana subspecies offers hope for more effective protection of these fascinating creatures. This, in turn, contributes to the long-term conservation of one of the Galapagos Islands’ most iconic species.