Skink

Skink
Skink family
Eastern blue-tongued lizard
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia (paraphyletic)
(unranked): Sauria
Order: Squamata
Suborder: Scleroglossa
Infraorder: Scincomorpha
Family: Scincidae
Gray, 1825
Subfamilies

Acontinae
Lygosominae
Scincinae (probably paraphyletic)
For genera, see text.

Skinks are lizards belonging to the family Scincidae. Together with several other lizard families, including Lacertidae (the "true" or wall lizards), they comprise the superfamily or infraorder Scincomorpha. With about 1200 described species, the Scincidae are the second most diverse family of lizards, exceeded only by the Gekkonidae (or geckos).

Contents

Description

Skinks look roughly like true lizards, but most species have no pronounced neck and their legs are relatively small; in fact several genera (e.g., Typhlosaurus) have no limbs at all. Some other genera, such as Neoseps, have reduced limbs, lacking forelegs, and with fewer than five toes (digits) on each foot. In such species, their locomotion resembles that of snakes more than that of lizards with well-developed limbs. As a general rule, the longer the digits, the more arboreal the species is likely to be. A biological ratio exists that can determine the ecological niche of a given skink species. The SENI (Scincidae Ecological Niche Index) is a ratio based on anterior foot length at the junction of the ulna/radius-carpal bones to the longest digit divided by the snout-to-vent length (SVL).[1]

Most species of skinks have long, tapering tails that they can shed if a predator grabs the tail. Such species generally can regenerate the lost part of a tail, though imperfectly. Species with stumpy tails have no special regenerative abilities.

Some species of skink are quite small; Scincella lateralis typically ranges from 3 to 5.5 inches (7.5 to 14.5 cm), more than half of which is tail. Most skinks however, are medium sized with snout-to-vent lengths of about 12 cm (4 or 5 in), although some grow larger; the Solomon Islands skink, (Corucia zebrata), is the largest known extant species and may attain a snout-to-vent length of some 35 cm (13 to 14 in).

Diet

Skinks are generally carnivorous and in particular insectivorous. Typical prey includes flies, crickets, grasshoppers, beetles, and caterpillars. Various species also eat earthworms, millipedes, snails, slugs, isopods, other lizards, and small rodents. Some species, particularly those favored as home pets, have a more varied diet and can be maintained on a regimen of roughly 60% vegetables/leaves/fruit and 40% meat (insects and rodents).[2]

Habitat

Trachylepis maculilabris mating
Female skink with eggs
Skink in Australia

As a family Skinks are cosmopolitan; species occur in a variety of habitats worldwide, apart from boreal and polar regions. Various species occur in ecosystems ranging from deserts and mountains to grasslands. Some species are endangered, such as the Androgynous Skink in New Zealand, with less than 100 reports since first being identified at Molesworth Station South Island by Keith Frankum.[citation needed]

Many species are good burrowers. There are more terrestrial or fossorial (burrowing) species than arboreal (tree-climbing) or aquatic species. Some are "sand swimmers", especially the desert species, such as the mole skink in Florida. Some use a very similar action in moving through grass tussocks. Most skinks are diurnal (day-active) and typically bask on rocks or logs during the day.

Breeding

Approximately 45% of skink species are viviparous. Many are ovoviviparous (hatching eggs internally and giving birth to live offspring). Some, such as the genera Tiliqua and Corucia, give birth to live young that develop internally, deriving their nourishment from a mammal-like placenta attached to the female – viviparous matrotrophy. However, a recently described example occurring in Trachylepis ivensi is the most extreme to date, of a purely reptilian placenta directly comparable in structure and function, to a eutherian placenta.[3] In skinks however, placental development of whatever degree is of course phylogenetically analogous, rather than homologous to functionally similar processes in mammals.

The approximately 55% of skink species that are oviparous (egg-laying) give birth in small clutches.

Predators

Raccoons, foxes, possums, snakes, coatis, crows, cats, dogs, herons, hawks, lizards, in short a wide variety of predators of small land vertebrates, also prey on various skinks.

Genera

Many large genera, Mabuya for example, are still insufficiently studied, and their systematics is at times controversial, see for example the taxonomy of the Western Skink, Eumeces skiltonianus. Mabuya in particular is being split, many species being allocated to new genera such as Trachylepis, Chioninia, and Eutropis.

Blood colour

Skinks in the genus Prasinohaema have green blood due to a buildup of the waste product biliverdin.

References

  1. ^ Schnirel, Brian (2004) SENI biometric analysis on the extinct Scincidae species: Macroscincus coctei. Polyphemos, Volume 1, Issue 2, May, Florence, South Carolina, U.S.A. pp. 12-22.
  2. ^ McLeod, Lianne. "Keeping Blue Tongued Skinks as Pets". http://exoticpets.about.com/cs/lizardsaspets/a/bluetongues.htm. Retrieved 2006-08-27. 
  3. ^ Blackburn, D. G. and Flemming, A. F. (2011), Invasive implantation and intimate placental associations in a placentotrophic african lizard, Trachylepis ivensi (scincidae) Journal of Morphology. doi: 10.1002/jmor.11011
  • De Vosjoli, Philippe (1993) Prehensile-Tailed Skinks. Advanced Vivarium Systems. ISBN 1-882770-24-2

External links


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Look at other dictionaries:

  • Skink — Skink, n. [L. scincus, Gr. ????.] [Written also {scink}.] (Zo[ o]l.) Any one of numerous species of regularly scaled harmless lizards of the family {Scincid[ae]}, common in the warmer parts of all the continents. [1913 Webster] Note: The… …   The Collaborative International Dictionary of English

  • Skink — Skink, v. t. [imp. & p. p. {Skinked}; p. pr. & vb. n. {Skinking}.] [Icel. skenja; akin to Sw. sk[ a]ka, Dan. skienke, AS. scencan, D. & G. schenken. As. scencan is usually derived from sceonc, sceanc, shank, a hollow bone being supposed to have… …   The Collaborative International Dictionary of English

  • Skink — Skink, v. i. To serve or draw liquor. [Obs.] [1913 Webster] …   The Collaborative International Dictionary of English

  • Skink — Skink, n. Drink; also, pottage. [Obs.] Bacon. [1913 Webster] …   The Collaborative International Dictionary of English

  • skink — skink·er; skink; …   English syllables

  • SKINK — (Heb. חֹמֶט, ḥomet), a reptile of the family Scincidae, of which six genera are found in Israel. These differ greatly in their bodily structure, some lacking legs entirely and resembling snakes, while others have atrophied feet or resemble the… …   Encyclopedia of Judaism

  • Skink — (Scincus); nach Daudin Gattung der Schlangeneidechsen; der Leib ist walzig, nach dem Schwanz zu dünner, Kopf u. Hals sind nicht getrennt, die Schuppen sind gleichförmig, glatt, liegen ziegelartig auf dem ganzen Körper, die vier Füße sind kurz u.… …   Pierer's Universal-Lexikon

  • Skink — (Glanzschleiche, Scincus Laur.), Eidechsengattung aus der Familie der Wühlechsen (Scincoidea), Reptilien mit konischem Kopf, unten plattem Körper, abgeplatteten, gesägt randigen Zehen und kegelförmigem Schwanz. Der gemeine S. (Meerskink, Scincus… …   Meyers Großes Konversations-Lexikon

  • Skink — Skink, Erdkrokodil, Apotheker S. (Scincus officinālis Laur. [Abb. 1751]), zu den Kurzzünglern gehörende Eidechse, graugelb, mit dunklen Querbändern; Nordafrika. Pulverisiert früher (als Stinkmarie oder Stinzmarie, verderbt aus Scincus marinus)… …   Kleines Konversations-Lexikon

  • Skink — Skink, lat. Scincus, Gattung Amphibien aus der Ordnung der Eidechsen, mit 4 5zehigen Füßen; der officinelle S. (S. officinalis). bis 8 lang, gelblich mit schwärzlichen Querbinden, fast beständig an der Sonne. In Syrien, Arabien, Nordafrika …   Herders Conversations-Lexikon

  • Skink — der; [e]s, e <über lat. scincus aus gr. skígkos »orientalische Eidechse«> (in Tropen u. Subtropen lebende) Echse mit keilförmigem Kopf, glatten, glänzenden Schuppen u. langem Schwanz, Wühl od. Glattechse …   Das große Fremdwörterbuch

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