New species of black iguana is discovered

A newly discovered species of melanistic black iguana (Iguana melanoderma) has been discovered in the Caribbean.

A study published in the open-access journal ZooKeys reveals that this new species was found in the Saba and Montserrat islands, the Lesser Antilles - in the Eastern Caribbean.

This creature appears to be threatened by unsustainable harvesting - including the pet trade - along with competition and hybridisation from escaped or released invasive alien iguanas from South and Central America.

The international team of researchers who discovered this iguana are calling for urgent conservation measures and for support for further research to investigate its relationship to other melanistic iguanas from the Virgin Islands and coastal islands of Venezuela.

This iguana species is genetically different from the other two endemic species of green iguana known in the area. 

The newly described species is characterised with “private microsatellite alleles, unique mitochondrial ND4 haplotypes and a distinctive black spot between the eye and the ear cavity (tympanum)”, according to the research paper.

Cells that control hair and skin colour in Iguana melanoderma are mutated, causing high concentrations of the dark pigment melanin, which is why this species is almost completely black.

This type of cell mutation is most frequently seen in panthers, but can also be found among other species of animal, such as penguin and coyote.

Researchers identified the new species by observing individuals in the wild, as well as taking photographs of them, and comparing them with specimens from various research institutions. 

DNA was extracted from 44 iguanas to confirm their findings.

On the island of Saba, Iguana melanoderma are considered a “flagship species” and are often located on cliffs, particularly in foggy and cool environments where they can be found sunbathing as the Sun rises.

“Priority actions for the conservation of the species Iguana melanoderma are bio-security, minimisation of hunting, and habitat conservation. The maritime and airport authorities of both islands must be vigilant about the movements of iguanas, or their sub-products, in either direction, even if the animals remain within the same nation's territory. 

“Capacity-building and awareness-raising should strengthen the islands' bio-security system and could enhance pride in this flagship species," concludes Prof. Grandjean. explains Frédéric Grandjean from the University of Poitiers, France.

The green iguana is classified as a species of “least concern” and because Iguana melanoderma is not differentiated under the International Union for Conservation of Nature (IUCN) Red List of Species, the researchers warn that the newly revealed black species may be at risk of extinction if not considered for protection.

Reference: Breuil Michel, et al; ‘Painted black: Iguana melanoderma (Reptilia, Squamata, Iguanidae) a new melanistic endemic species from Saba and Montserrat islands (Lesser Antilles)’, ZooKeys, (13 April, 2020), DOI: https://zookeys.pensoft.net/article/48679/