Nidua fringe-fingered lizard (Acanthodactylus scutellatus)

Description

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Nidua fringe-fingered lizard fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
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Nidua fringe-fingered lizard description

The Nidua fringe-fingered lizard (Acanthodactylus scutellatus) is a medium-sized lizard with a slender body and elongated, pointed snout ^{(2) (4) (5)}. It is named for the fringe-like scales on its toes ^{(2) (4) (5)}, which provide traction for running on loose sand ⁽⁶⁾. The scientific name of the Nidua fringe-fingered lizard, scutellatus, is derived from the Latin for ‘small shield’, and refers to this lizard’s small body scales ⁽²⁾.

Both adult and juvenile Nidua fringe-fingered lizards are pale in colour ^{(5) (7)}, and the back and flanks of the adult show a black criss-cross pattern ^{(4) (7)}, giving the appearance of a network of spots. During the breeding season, the adult female may display a striking salmon-red colour on the underside of the tail ⁽⁷⁾. Juvenile Nidua fringe-fingered lizards have four white bands, two on each side of the body ^{(2) (4)}, as well as a blue-tinged tail ^{(4) (7)}.

The Nidua fringe-fingered lizard can be quite variable in appearance, even within the same population ⁽⁷⁾, and at least two subspecies have been identified, Acanthodactylus scutellatus scutellatus and Acanthodactylus scutellatus audouini ^{(1) (5)}. A third subspecies, Acanthodactylus scutellatus hardyi, is now generally considered to be a separate species ⁽¹⁾.

Also known as

fringe-toed lizard, Nidua fringed toed lizard, Nidua fringe-toed lizard, Nidua lizard, shielded spinefoot.

Synonyms

Acanthodactylus inornata, Lacerta scutellata.

Size

Snout-vent length: 6.3 - 6.6 cm ⁽²⁾

Tail length: 11 cm ⁽²⁾

Weight

c. 3 g ⁽³⁾

Nidua fringe-fingered lizard biology

The Nidua fringe-fingered lizard shelters in burrows that may measure up to 30 or 40 centimetres deep ^{(2) (3)}. Individuals may dig up to three burrows in one small area, usually on a slope beneath tufts of vegetation, and can often be found basking at the burrow entrance. In response to a potential predator, the lizard will flee into the burrow for refuge ⁽²⁾. The Nidua fringe-fingered lizard is usually active during the day ⁽⁸⁾.

The diet of the Nidua fringe-fingered lizard consists mainly of small invertebrates such as ants, beetles, termites, flies and other insects ^{(2) (3)}. This species has a sit-and-wait foraging strategy, lying in wait for passing prey ⁽⁹⁾. Although the Nidua fringe-fingered lizard has not been seen eating vegetation, analysis of its stomach contents has found relatively large quantities of plant matter, suggesting that this species’ diet may not be restricted to invertebrates ⁽³⁾.

In captivity, the female Nidua fringe-fingered lizard has been recorded laying up to 4 clutches of eggs between May and June, with intervals of around 7 to 14 days between clutches. The clutch size ranges from one to four eggs. On hatching, the juvenile Nidua fringe-fingered lizard measures about 3 centimetres long and weighs 0.8 to 1.8 grams ⁽³⁾.

Although the Nidua fringe-fingered lizard can be seen year-round, it usually reduces its activity in winter, only becoming active during warm weather. Individuals emerge again in the spring ⁽³⁾.

The Nidua fringe-fingered lizard reaches sexual maturity very early on, with juveniles beginning to reproduce once they reach a snout-vent length of about five centimetres. Individuals of this size are able to breed immediately after emerging in the spring, but smaller individuals must spend another few weeks feeding and growing before they are large enough to reproduce ⁽³⁾.

The life expectancy of this species is short, with a maximum lifespan in the wild of just one year ⁽³⁾. The Nidua fringe-fingered lizard’s predators include a variety of desert species, such as scorpions ⁽²⁾.

Nidua fringe-fingered lizard range

This lizard is widely distribution over the sandy regions of North Africa, from Algeria and Mali to Egypt and Sudan. It also stretches into the Arabian Peninsula, Israel, Iraq and Kuwait ^{(1) (2) (4) (5)}.

Nidua fringe-fingered lizard habitat

The Nidua fringe-fingered lizard is typically found in sandy habitats, from sand dunes to sandy areas on rocky ground ^{(3) (5) (8) (9)}. It is usually found in regions with low amounts of plant cover ⁽³⁾ or low thicket vegetation ⁽²⁾. These areas enable the Nidua fringe-fingered lizard to dig retreat holes at the base of tufts of vegetation ⁽²⁾.

Nidua fringe-fingered lizard status

The Nidua fringe-fingered lizard has yet to be classified by the IUCN.

Nidua fringe-fingered lizard threats

The Nidua fringe-fingered lizard is one of the most abundant species of lizard in parts of the northern Sinai Peninsula ^{(7) (10)}. However, its short lifespan and small clutch size make its populations highly vulnerable to local events, such as adverse weather conditions or droughts ⁽³⁾.

This species is not currently known to be facing any major threats, but its status on the National Red List of Israel, where 20 percent of its world population is found, is reported as ‘Near Threatened’ ⁽¹¹⁾.

Nidua fringe-fingered lizard conservation

There are not known to be any specific conservation measures currently in place for the Nidua fringe-fingered lizard.

Find out more

Find out more about the Nidua fringe-fingered lizard and other reptile species:

• The Reptile Database:
  http://reptile-database.reptarium.cz/search.php

More information on reptile conservation:

• International Reptile Conservation Foundation:
  http://www.ircf.org/

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

This species information was authored as part of the ARKive and Universities Scheme.

Glossary

Invertebrates

Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Snout-vent length

A standard measurement of body length of reptiles. The measurement is from the tip of the nose (snout) to the anus (vent), and excludes the tail.

Subspecies

A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

References

1. The Reptile Database (February, 2011)
   http://reptile-database.reptarium.cz/search.php
2. Schleich, H.H., Kästle, W. and Kabisch, K. (1995) Amphibians and Reptiles of North Africa. Koeltz Scientific Books, Koenigstein, Germany.
3. Perry, G. and Dmi’el, R. (1994) Reproductive and population biology of the fringe-toed lizard, Acanthodactylus scutellatus, in Israel. Journal of Arid Environments, 27: 257-263.
4. Salvador, A. (1982) A revision of the lizards of the genus Acanthodactylus (Sauria: Lacertidae). Bonner Zoologische Monographien, 16: 1-167.
5. Crochet, P.A., Geniez, P. and Ineich, I. (2003) A multivariate analysis of the fringe-toed lizards of the Acanthodactylus scutellatus group (Squamata: Lacertidae): systematic and biogeographical implications. Zoological Journal of the Linnean Society, 137: 117-155.
6. Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.
7. Baha El Din, S. (2006) A Guide to the Reptiles and Amphibians of Egypt. American University in Cairo Press, Cairo.
8. Pérez-Mellado, V. (1992) Ecology of lacertid lizards in a desert area of eastern Morocco. Journal of Zoology, 226(3): 369-386.
9. Perry, G., Lampl, I., Lerner, A., Rothenstein, D., Shani, E., Sivan, N. and Werner, Y.L. (1990) Foraging mode in lacertid lizards: variation and correlates. Amphibia-Reptilia, 11: 373-384.
10. Ibrahim, A.A. (2001) The reptile community of the Zaranik Protected Area, North Sinai, Egypt with special reference to their ecology and conservation. Egyptian Journal of Natural History, 3: 81-92.
11. National Red Lists (February, 2011)
    http://www.nationalredlist.org/