''Lygodactylus williamsi'' is a

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Gekkonidae Gekkonidae (the common geckos) is the largest family of geckos, containing over 950 described species in 62 genera. The Gekkonidae contain many of the most widespread gecko species, including house geckos (''Hemidactylus''), the tokay gecko (''Ge ...

. The species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to a small area of

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

. Common names include turquoise dwarf gecko, William's dwarf gecko and, in the pet trade, electric blue gecko or electric blue day gecko. Illegally wild-caught specimens are widely sold in the pet trade, often falsely promoted as captive-bred. Although ''L. williamsi'' breeds in captivity, the young require a lot of specific care, making large-scale breeding difficult. There is some specialist breeding, with one very large breeder claiming to have produced about a thousand individuals , but no large-scale professional breeding. A

captive breeding Captive breeding, also known as captive propagation, is the process of keeping plants or animals in controlled environments, such as wildlife reserves, zoos, Botanical garden, botanic gardens, and other Conservation biology, conservation facilitie ...

project and

studbook A breed registry, also known as a herdbook, studbook or register, in animal husbandry, the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeders w ...

was initiated by EAZA-registered zoos in 2013. ''L. williamsi'', as a species, was placed under EU Appendix B protection (December 2014) and EU Appendix A protection (January 2017), and given

CITES Appendix I CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of inte ...

protection in January 2017, as well. The gecko may not be kept or sold in the EU without documentation and permits, renewable every three years, and geckos must now be registered. Similar restrictions apply in many other jurisdictions.

Population

The survival of ''L. williamsi'' is mostly threatened by (entirely illegal) collection for the international pet trade. It is

and the population is thought to be declining rapidly. Although trade in wild-caught turquoise day geckos is illegal, wild-caught geckos are commonly sold in pet shops. It is estimated that between December 2004 and July 2009, at least 32,310 to 42,610 geckos were taken by one collecting group, ~15% of the wild population at the time.

Geographic range

''L. williamsi'' is only found in of the Kimboza Forest, Ruvu Forest Reserve, Mbagalala and Muhalama at an altitude of .United Nations Environment Programme World Conservation Monitoring Centre (November 2013).
Review of Lygodactylus williamsi.
'. Retrieved 27 October 2015. These are located at the foothills of the Uluguru Mountains in eastern

. The subpopulation in Kimboza Forest Reserve was estimated at 150,000 adults in 2009. The size of the remaining subpopulations is unknown, but their size is not thought to contribute significantly to the total population. The two known sites outside protected areas are tiny: one consists of 14 ''

Pandanus ''Pandanus'' is a genus of monocots with about 578 accepted species. They are palm-like, dioecious trees and shrubs native to the Old World tropics and subtropics. Common names include pandan, screw palm and screw pine. The genus is classified ...

'' trees (the rest has been cleared for

banana plantation A banana plantation is a commercial agricultural facility found in tropical climates where bananas are grown. Geographic distribution Banana plants may grow with varying degrees of success in diverse climatic conditions, but commercial banana pl ...

s) and the other is equally close to disappearing.Maisch H (2013). "Reasons to feel blue". ''Zooquaria'' 83: 24.

Habitat

In the wild, the turquoise day gecko lives exclusively on the (redlisted endemic) screwpine, '' Pandanus rabaiensis'', mostly in the leaf crown. It only lives on large trees, those with leaves more than long.CITES Proposal for inclusion
/ref> A single leaf crown will typically contain a single individual, or an adult male, an adult female, and juveniles. It eats small

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s and fruit and drinks water from leaves. It is also fond of

nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

Habitat loss

Collectors commonly cut down screwpine trees to reach the geckos living in the leaf crest, destroying the gecko's habitat. Many geckos are thought to die while being shipped to market. The pet trade is likely a worse threat than habitat loss. The gecko is now restricted to the forest in Tanzania and is at risk of extinction in the wild as the forests are cleared. ''L. williamsis tropical forest habitat is also shrinking and fragmenting. Neither of the Catchment Forest Reserves where it occurs is well-protected. The forest is seriously threatened by pet collectors, clearing for farmland,

illegal logging Illegal logging is the harvest, transportation, purchase, or sale of timber in violation of laws. The harvesting procedure itself may be illegal, including using corrupt means to gain access to forests; extraction without permission, or from a p ...

, increasingly frequent fires, mining of rubies,

tourmaline Tourmaline ( ) is a crystalline silicate mineral, silicate mineral group in which boron is chemical compound, compounded with chemical element, elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. This gemstone comes in a ...

rhodolite Rhodolite is a varietal name for rose-pink to red mineral pyrope, a species in the garnet group. It was first described from Cowee Valley, Macon County, North Carolina. The name is derived from the Greek "rhodon" for "rose-like", in common wi ...

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

and dolomite and

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

from outcrops on which the screwpines grow. Invasive trees such as ''

Cedrela ''Cedrela'' is a genus of several species in the mahogany family, Meliaceae. They are evergreen or dry-season deciduous trees with pinnate leaves, native to the tropical and subtropical New World, from southern Mexico south to northern Argentina. ...

'' are also a threat. There is little forest left unaffected.

Appearance

Adult snout-vent length (SVL) is . Males of ''L. williamsi'' are bright blue with heavy black throat stripes, visible preanal pores, and hemipenile bulges. Females range from brown or bronze to bright green, and have little to no black on the throat. Females can easily be confused with juvenile or socially suppressed males that are also green, sometimes with a bluish cast. Juveniles have colouring similar to females, but more orange in tone. The underside of both sexes is orange to yellow, often with areas of both colours. Colours of individuals vary according to mood and temperature. Males may range from black or gray to brilliant electric blue. Females may range from dark brown to brilliant green with turquoise highlights. A well-illustrated ''Lygodactylus spp.'' identification guide has been published online by

CITES CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of inte ...

,"How to Identify ''Lygodactylus williamsi'': A photographic Guide to the Turquoise Dwarf Gecko"

TRAFFIC Traffic is the movement of vehicles and pedestrians along land routes. Traffic laws govern and regulate traffic, while rules of the road include traffic laws and informal rules that may have developed over time to facilitate the orderly an ...

(2011). In: Wildlife Trade Handbook. TRAFFIC East/Southern Africa and the Mohamed bin Zayed Species Conservation Fund, Dar es Salaam, Tanzania. 11–17. largely for the use of customs officers (illegal shipments of these geckos are often intentionally mislabelled).

Behavior

Like all geckos of the

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

Lygodactylus ''Lygodactylus'' is a genus of Diurnality, diurnal geckos with 82 species. They are commonly referred to as dwarf geckos. They are mainly found in Africa and Madagascar although two species are found in South America. ''Lygodactylus picturatus'' ...

'' and '' Phelsuma'', ''L. williamsi'' is diurnal. It is bold, active, and social. Males are territorial, and do not generally tolerate the presence of other males. Social gestures include lateral flattening, puffing out of the throat patch, head shaking and head bobbing, and tail-wagging.

Reproduction

Males of ''L. williamsi'' court females with lateral flattening, puffing out of the throat pouch, and head bobbing. Two to three weeks after copulation, the female lays a

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

of 1 or 2 pea-sized white, hard-shelled eggs which are glued to a surface in a secure, hidden location. Eggs hatch in 60 to 90 days.

Etymology

The specific name, ''williamsi'', given to the gecko by

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

Arthur Loveridge Arthur Loveridge (28 May 1891 – 16 February 1980) was a British people, British biologist and Herpetology, herpetologist who wrote about animals of East Africa, particularly Tanzania, and of New Guinea. He gave Binomial nomenclature, scientific ...

, Loveridge A (1952). "A startlingly turquoise-blue gecko from Tanganyika". ''Journal of the East African Natural History Society'' 20: 446. (cited in the IUCN database as the species authority). honours American

herpetologist Herpetology (from Ancient Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is a branch of zoology concerned with the study of amphibians (including frogs, salamanders, and caecilians (Gymnophiona)) and reptiles (in ...

Ernest Edward Williams Ernest Edward Williams (January 7, 1914 – September 1, 1998) was an American herpetologist. He coined the term '' ecomorph'' based on his research on anoles. Taxa named in honor of Ernest E. Williams The following species are named in honor o ...

.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Lygodactylus williamsi'', p. 286).

References

*UNEP-WCMC Species Database

External links

*The Reptile Database entry: http://reptile-database.reptarium.cz/species?genus=Lygodactylus&species=williamsi *Catalogue of Life taxonomic entry: http://www.catalogueoflife.org/col/details/species/id/13201544 * {{Taxonbar, from=Q137615 Lygodactylus Species that are or were threatened by the pet trade Species that are or were threatened by deforestation Species that are or were threatened by logging for timber Species that are or were threatened by logging for firewood Species that are or were threatened by agricultural development Species that are or were threatened by fires Species that are or were threatened by mining Reptiles of Tanzania Endemic fauna of Tanzania Reptiles described in 1952 Reptiles as pets