''Cyclura'' is a
genus of
lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
s in the
family Iguanidae. Member
species of this
genus are commonly known as "cycluras" or more commonly as rock iguanas and only occur on islands in the
West Indies.
Rock iguanas have a high degree of
endemism, with in most cases a single species or
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
restricted to an individual island.
Taxonomy
The genus ''Cyclura'' was first
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
by
Richard Harlan in 1825 to include two new species of lizard: ''C. carinata'' and ''C. teres''. ''C. teres'' eventually turned out to be a
junior synonym
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently.
* In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...
of ''
Ctenosaura acanthura
''Ctenosaura acanthura'', is a species of iguanid lizard found in eastern Mexico and extreme western Guatemala. The standardized English name is the Mexican spiny-tailed iguana (Spanish: garrobo del noreste).Liner, E. A. and G. Casas-Andreu. 2008 ...
''.
In the 20th century there were eight recognised species of ''Cyclura'' and nine additional
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
(one extinct) besides the
nominotypical subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
.
Recently, certain subspecies were elevated to species status.
Currently, there are ten species in this genus.
Habitat
Rock iguanas most often inhabit subtropical zones, of Caribbean island
dry forest biomes
A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...
. These landscapes are characterised by rocky outcrops, rugged cliffs, hills, weather-eroded
limestone features and moderate to sparse vegetation; they live in many types of environments, from moderately dry
acacia
''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...
forest, to much hotter
mesquite and dry
cactus landscapes. The reptiles enjoy sunning themselves on exposed rock faces, since they are naturally cold-blooded animals, and therefore must regulate their internal temperature. Caribbean islands are often made up of heavily weathered
limestone, which ultimately forms natural caves for animals to take shelter in.
[
]
Diet and longevity
All rock iguanas are
herbivorous, consuming leaves, flowers, berries, and fruits from different plant species. Their diet is very rarely supplemented with insect larvae, crabs, slugs, dead birds, and fungi; individual animals do appear to be opportunistic carnivores.
A study in 2000 by Allison Alberts revealed that seeds passing through the digestive tracts of ''C. nubila nubila'' rock iguanas germinate more rapidly than those that do not. These seeds in the fruits consumed by this species have an adaptive advantage by sprouting before the end of very short rainy seasons. She theorised these iguanas may be an important means of distributing such seeds to new areas.
The record for the longest lived captive-born rock iguana is held by a Lesser Caymans iguana, which lived for 33 years in captivity.
A
blue iguana captured on
Grand Cayman in 1950 by naturalist Ira Thompson was imported to the
United States in 1985 by Ramon Noegel and sold to reptile importer and breeder, Tom Crutchfield. Crutchfield loaned this iguana to the
Gladys Porter Zoo
Gladys Porter Zoo is a zoological and botanical park located in Brownsville, Texas, United States. The zoo officially opened on September 3, 1971, and currently averages over 424,000 visitors annually. Situated on , the zoo houses about 400 anima ...
in
Brownsville, Texas
Brownsville () is a city in Cameron County in the U.S. state of Texas. It is on the western Gulf Coast in South Texas, adjacent to the border with Matamoros, Mexico. The city covers , and has a population of 186,738 as of the 2020 census. It ...
in 1997. The lizard was named
Godzilla by the zoo staff and was kept until his death in 2004. Thompson estimated the iguana to be 15 years of age at the time of its capture. This lizard may have been the word's longest-living recorded lizard at 69 years of age, having spent 54 years in captivity.
Reproduction
All species of ''Cyclura'' are
sexually dimorphic; males are larger than females, and have more prominent
dorsal crests as well as larger
femoral pores on their thighs, which are used to release
pheromones.
The particulars vary slightly among species and subspecies, the rock iguanas reach sexual maturity at three to seven years of age. Females become sexually mature at two to five years of age. Males can be highly
territorial
A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal.
In international politics, a territory is usually either the total area from which a state may extract power resources or a ...
with the notable exception of the
Exuma Island iguana. Mating takes place at the beginning of or just prior to the first rainy season of the year (May to June) and lasts for two to three weeks. Females lay from 2 to 34 eggs, with an average clutch size of 17 within 40 days. Females of most species guard their nests for several days after laying their eggs, and incubation lasts approximately 85 days. It has been noted that ''Cyclura'' eggs are among the largest lizard eggs produced in the world.
Conservation
In 1996 nine of these taxa were assessed as
critically endangered, four taxa are
endangered and three species have been identified as vulnerable; one subspecies is believed to be extinct. In addition to small numbers typical of endemic island-dwelling animals, wild populations of these lizards are directly and indirectly impacted by land development,
overgrazing by domestic and
feral livestock and predation by introduced mammals such as hogs,
cats,
rat
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...
s,
dogs, and
mongooses.
In 1990, the
American Zoo and Aquarium Association
The Association of Zoos and Aquariums (AZA), originally the American Association of Zoological Parks and Aquariums, is an American 501(c)(3)
nonprofit organization founded in 1924 and dedicated to the advancement of zoos and public aquariums in ...
(AZA) designated the genus ''Cyclura'' as their highest priority. Their first project was a captive breeding program for the Grand Cayman iguana, which at the time was the most critically endangered of all the species of ''Cyclura''.
The
Indianapolis Zoo was involved in research and conservation of all sixteen taxa of West Indian iguanas. This includes collaborative work on establishing baseline biological information in captive and wild iguanas, scientific investigation, conservation efforts, field research and
captive breeding
Captive breeding, also known as captive propagation, is the process of plants or animals in controlled environments, such as wildlife reserves, zoos, botanic gardens, and other conservation facilities. It is sometimes employed to help species that ...
programs.
References
External links
All about CyclurasBlue Iguana Recovery Program (B.I.R.P.)the International Reptile Conservation Foundationthe Durrell Wildlife Conservation TrustReptile Stamps - Stamps featuring pictures of West Indian iguanas
{{Taxonbar, from=Q1205923
Lizard genera
Reptiles of the Caribbean
Taxa named by Richard Harlan