Agama stellio

is a moderately sized (SVL up to 30 cm) diurnal tree and rock dwelling agamid lizard. This lizard is characterised by its braod triangular head (in dorsal view), a distinct neck and strong legs with imbricate scales. The fingers have long and sharp claws. The tail shows rows of spiny scales. The lizards are usually brownish but may show blue scales on head and body in male lizards. The ventral side is pale yellowish or even white.

Systematics and biogeography

According to Daan (1967) five subspecies are distinguished:


Agama stellio picea from East Jordan;

Agama stellio vulgaris from Northwest Egypt;

Agama stellio brachydactyla from the Negev desert, Sinai, and Saudi Arabia;
Agama stellio stellio from Turkey, Iraq, Syria, Lebanon, Jordan, Israel, the Sporades, Delos, and Mykonos;
Agama stellio cypriaca from Cyprus.
Ecology

A. stellio lives in sandy biotopes, on and near rocks, walls, and on the stem of olive and/or dade trees. When startled, the lizards run for cover and hide in small crevaces. Males usually possess a teritory which they defend fiercely by head shaking, and chasing of the oponents. Agama stellio is an insectivore that will eat crickets, spiders, beetles, etc...

References


Birkenmeier, E. (1952) Feldbeobachtungen an Agama stellio stellio Linne und Lacerta sicula hieroglyphica Berthold.
Die Aquarien-u. Terrarien. Ztschr. 2: 50-51.
Daan, S. (1967) Variation and taxonomy of the Hardun, Agama stellio (Linnaeus, 1758) (Reptilia, Agamidae)
Beaufortia 172(14): 109-134.
Gorman, G.C. and D. Sochat (1972) Multiple lactate dehydrogenase alleles in the lizard Agama stellio.
Experientia 28(3): 351-353.
Haas, G. (1951) A New subspecies of Agama stellio (L.) from Southern Israel (Negev), Agama stellio brachydactyla subsp. nov. Ann. Mag. nat. Hist. 4(12): 1052-1053.
Henle, K. (1995) A brief review of the origin and use of 'stellio' in herpetology and a comment on the nomenclature and taxonomy of agamids of the genus Agama (sensu lato) (squamata: Sauria: Agamidae). Herpetozoa 8(1/2): 3-9.
Herrel, A., J. Cleuren and F. De Vree (1995) Prey capture in the lizard Agama stellio.
J. Morphol. 224: 313-329.
Herrel, A., J. Cleuren and F. De Vree (1996) Kinematics of feeding in the lizard Agama stellio.
J. Exp. Biol. 199: 1727-1742.
Huey, R.B., and P.E. Hertz (1982) Effects of body size and slope on sprint speed of a lizard (Stellio (Agama) stellio).
J. Exp. Biol. 97: 401-407.
Loumbardis, N.S., and A. Hailey (1985) Activity metabolism of the lizard Agama stellio stellio.
Comp. Biochem. Physiol. 82(A): 687-691.
Simons, R. (1877) Ein Beitrag zur Kenntnis des Hardun.
Zoologische Garten 18: 314-321.


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Uromastix acanthinurus
Uromastix acanthinurus is a rather large dorso-ventrally flattened lizard with short, strong legs and a large, broad and spiny tail (hence the name "spiny-tailed" lizard). These lizards also posess a rather triangular head, small eyes and a short and blunt snout. On the inner aspect of the hind legs femoral pores are present. The dorsal scales are markedly smaller than the larger ventral scales. Both the adults and juveniles are gray-brownish dorsally and whitish on throath and ventral side. However, after basking color changes appear and red, yellow black and blue colors can be seen.

Systematics and biogeography of Uromastix sp.

Originally 13 species were recognised by Wermuth (1967). However, a recent study by Moody (1987) showed that at least 15 species can be recognised. These species are distributed in N-W India, throughout the whole of S-W Azia and the Arabian Peninsula all the way up to the Saharan region in Africa and the dry coastal regions of Ethiopia and Somalia. According to Moody (1980; 1983), the genus Uromastix forms together with the genus Leiolepis (S-E Asia) a monophyletic taxon.

Ecology

Most of the time animals can be found basking on a rock. U. acanthinurus is a true desert animal that can be found basking even the hottest parts of the day. The animals dig their own burrow which can vary in length from 80 cm up to 3 m. This burrow is characterised by a semi-circular entrance often closed with sand when the animal is hiding in its burrow (Minton, 1966). When disturbed the animals head for their burrow. When trying to remove an animal from its burrow, the animal resists strongly using its spiny tail. Once it becomes hot enough the animals go search for food; the rest of the day the animals bask in the sun. Their food consists of all sorts of plants. After sundown the animals return to their burrow and stays their for the night.

References


Abdullah, H. (1960) Notes on the spiny-tailed lizard, Uromastix hardwickii (Gray).
Journal Bombay Natural Hist. Society 57(2): 421-423.
Al-Ogily, S.M., and A. Hussain (1983) Studies on the ecology of the egyptian spiny tailed lizard, Uromastix aegyptius (Forskal, 1775) in the Ryadh region, Saudi Arabia. J. Coll. Sci. King Saud Univ. 14(2): 341-351.
Bhatnagar, R.K., R.K. Bhanotar, Y. Mahto, and Y.N. Srivastava (1979) Winter temperature gradient in tunnels of Uromastix hardwickii (Gray). Journal Bombay Natural Hist. Society 76: 172-173.
Bouskil, A. (1983) The burrows of the dabb-lizard, Uromastix aegyptius
Isr. J. Zool. 32: 151-152.
Bouskil, A. (1986) Habitat selevtion in the desert lizard Uromastix aegyptius and its relation to the autecological hypothesis. In: Environmental quality and ecosystem stability (eds: Dubinsky, Z. and Steinberger, Y.) , Vol III A/B, Bar-Ilan University Press, Ramat-Gan, Israel. pp. 119-128.
Bouskil, A. (1987) Feeding in the herbivorous lizard Uromastix aegyptius near Hazeva.
Isr. J. Zool. 33: 122.
Champaka, S. (1957) Water conservation in Uromastix hardwickii (Gray), with a note on the presence of Mullerian ducts in the male. J. Zool. Soc. India 9: 103-113.
Dickson, V.P. (1965) Plants eaten by Uromastix microlepis and other notes on this lizard in Eastern Arabia.
Journal Bombay Natural Hist. Society 62(3): 565-566.
Dubuis, A., L.Farel, C. Grenot, and R. Vernet (1971) Sur le regime alimentaire du lezard saharien Uromastix acanthinurus Bell. C. R. Acad. Sc. Paris. Vol. 273 Serie D: 500-503.
Foley, W.J., A. Bouskila, A. Shkolnik, and I. Chosniak (1992) Microbial digestion in the herbivorous lizard Uromastix aegyptius (Agamidae). J. Zool. Lond. 226: 387-398.
Grenot, C. (1974) Polymorphisme chromatique du lezard agamide Uromastix acanthinurus Bell dans les populations du Shara Nord Occidental. Bull. Soc. Zool. France 99(1): 153-164.
Grenot, C. and R. Vernet (1973) Les lezards heliophiles du Sahara: facteurs ecologiques et conditions d'elevage.
Bull. Soc. Hist. nat. Afr. Nord Alger. 64(1/2): 53-78.
Joger, U. (1986) Phylogenetic analysis of Uromastyx lizards, based on albumin immunological distances.
In: Studies in herpetology (ed. Z. Rocek), Prague. pp: 187-191.
Muller, L. (1922) Uber eine neue Uromastix-Art aus der Zentral-Sahara.
Naturwiss. Beob. 63(15/16): 193-201.
Krabbe-Paulduro, U. and E. Paulduro (1988) Pflege und Nachzucht der Afrikanischen Dornschwanzagame Uromastix acanthinurus Bell 1825. Salamandra 24(1): 27-40.
Mandaville, J. (1965) Plants eaten by Uromastix microlepis and other notes on this lizard in Eastern Arabia.
Journal Bombay Natural Hist. Society 62(1): 161-163.
Mertens, R. (1962) Bemerkungen uber Uromastyx acanthinurus als Rassenkreis (Rept. Saur.)
Senck. Biol. 43(6): 425-432.
Moody, S.M. (1987) A preliminary cladistic study of the lizard genus Uromastyx (Agamidae, sensu lato), with a checklist and diagnostic key to the species. Proc. Fourth Ord. Gen. Meet. Soc. Europ. Herp., Nijmegen, Holland. pp: 285-288.
Throckmorton, G.S. (1976) Oral food processing in two herbivorous lizards, Iguana iguana (Iguanidae) and Uromastix aegyptius (Agamidae). J. Morphol. 148: 363-390.
Throckmorton, G.S. (1978) Action of the pterygoideus muscle during feeding in the lizard Uromastix aegyptius (Agamidae).
Anat. Rec. 190: 217-222.
Throckmorton, G.S. (1980) The chewing cycle in the herbivorous lizard Uromastix aegyptius (Agamidae).
Arch. Oral Biol. 25: 225-233.


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HOW TO INDENTIFY AN AGAMA LIZARD


Of the 50 lizards that belong to the Agamidae family, the agama is considered to be the genus. The Agamidae family is related to the iguanas and includes in its 200 species such types as the Australian Moloch or thorny devil, the frilled lizard and the flying dragons. The best know of the agama is the foot long agama, which is common in Africa. A male agama's head is bright terracotta and his body is dark blue. He has a tail that is banded with pale blue, white, orange and black. The skin of this lizard is rough to the touch, almost feeling like sandpaper. He has a dewlap of loose skin under his chin and a row of tiny spines on his neck that looks like the comb of a young cock. The agama is the most common reptile in West Africa. If you ever visit the region you can't miss seeing one within the first three minutes you are there. They run up and down the walls of the huts and stores in the villages, even scampering across compounds. Agamas are mainly insectivorous. The can be seen chasing their prey at high speeds and catching small insects with their tongue or snapping up larger ones directly with their mouth. They have incisor like front teeth that are pointed like those of insectivorous mammals. They may also eat grass, berries, seeds and the eggs of smaller lizards. The common agama is polygamous. The beautifully colored male can often be seen with half a dozen females in a territory he will defend vigorously. When the agama courts, he comes along side the female bobbing his head and then, if she allows him, grips her neck with his jaws. When the female is not in breeding condition the male will continue bobbing until he is exhausted. Agamas have a very definite breeding season, which always occurs after the long rains of March through May. The females can only lay eggs from June to September, which is when the insect population rises. This provides the female with an ample supply of protein for the formation of eggs. The female will lay up to twelve eggs in clutches. Mature male agamas that are dominant maintain the bright orange and blue coloring. Weak or subordinate males are dull brown in color. In most cases the common agama has adapted its ways to become a companion of man. Many live in the thatch of huts, emerging to feed on scraps and insects. During the day the agama is extremely active but in the afternoons, when temperatures reach 100 degrees Fahrenheit in the shade, they try to find a cool spot and lie down. Agamas always appear to be quarrelling. Fights are constantly breaking out between the colorful males. Even the females chase and fight each other, and sometimes the tiny hatchling lizards play at fighting. When dusk comes the agamas congregate in a communal roosts, usually in the eaves of houses. During this time all males, no matter what their social standing, turn a dull brown color all over. But with the rising of the sun, the brilliant colors return. After a cold night the agama will be literally stiff with cold. It then absorbs energy from the sun, which raises its body temperature so it can carry on with hunting and courting activities. The agama can tolerate greater temperatures than most reptiles, but must be careful not to overheat as the suns power increases. Sparse scrub of the desert gives them sufficient shelter as they dash from one bush to another going about their daily business. Title: How to identify an agamaDescription: Learn to identify an agama.Of the 50 lizards that belong to the Agamidae family, the agama is considered to be the genus. Copyright 2001 by PageWise, Inc.

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