SPECIES DESCRIPTION

The Grand Cayman Blue Iguana was originally described by Grant (1940) as Cyclura nubila lewisi, a subspecies of the Cuban Iguana, Cyclura nubila nubila. Only in 2002, was the renamed Cyclura lewisi granted full species status. The Blue Iguana is a large lizard, weighing as much as 20 lbs and exceeding 5 feet in length. They are exquisitely blue, have dark eyes encircled by red, big jowls with conical scales, and a spiky dorsal crest running from the neck to the tip of the long, lashy tail. The natural life span of a Cayman Blue can exceed 60 years.

Blue Iguana’s Relatives

The Blue Iguana is one of the West Indian Rock Iguanas, which are all classified in the genus Cyclura. Uniquely different species of Cyclura are found from the Virgin Islands through the Greater Antilles to the Bahamas.

The most ancient Rock Iguana is Cyclura pinguis, which survives on Anegada. Like the Blue Iguana, it is now critically endangered. It was the ancestor to this iguana which dispersed first from the Puerto Rico bank to Hispaniola, then onwards to the north and western islands, which has since diversified on different islands into 9 species and several additional subspecies.

The Blue Iguana evolved more recently from ancestors of its nearest relative, the Cuban Iguana (Cyclura nubila). Cuban Iguana ancestors also made the crossing to Little Cayman and Cayman Brac, where they evolved into a unique subspecies, Cyclura nubila caymanensis, and to the southern Bahamas where they evolved into a new species, Cyclura cychlura.

The Blue Iguana was long thought to be another subspecies of the Cuban Iguana, and but recent genetic evidence has led to a revision, and the Blue Iguana is now considered a unique species, Cyclura lewisi. If Cyclura lewisi and Cyclura nubila caymanensis are artificially brought into contact, they can still breed and produce fertile offspring. Naturally, they have always been separated by at least 67 miles of open ocean.