On the distribution of four species of agama (Agamidae) in Turkey

Abstract

The distribution of the Hardun, Agama stellio, the Caucasian Agama, Agama caucasia, the Syrian Agama, Agama ruderata, and Phrynocephalus helioscopus, in Turkey is presented with dot maps A. stellio and A. caucasia are sharply separated both horizontally and vertically. The area of A. stellio is defined by the March isotherm of 8°C and the July and August isotherms of 24°C. A. ruderata occurs in the large steppe areas of Inner and South-east Anatolia, but not in those of Eastern Anatolia.     

Bayesian inference of species diffusion in the West African Agama agama species group (Reptilia,Agamidae)

The savannah and tropical forest biomes of Africa have a long history of expansion and contraction, and the recent and rapid spread of dry savannah habitats has influenced the spatial and temporal diversification of vertebrate taxa across this region. We used a combination of species tree and phylogeographic methods to describe the spatio-temporal changes through time and across space (= species diffusion) in a clade of seven West African lizard species in the Agama agama species group. A Bayesian species tree diffusion approach was used to compare the relative rates at which species ranges changed across the landscape. We found that some species have high diffusion rates characterized by significant movement in their range location and minor changes to their overall range size, whereas other species show little movement in their range centre with an exponential increase in range size. This discrepancy between the rates that range locations shift versus change in their relative area could be linked to populations tracking their preferred habitats through time. A continuous Bayesian phylogeography approach using a relaxed random walk model was used to estimate the timing and rate of population size change and geographic diffusion in A. picticauda, the single species in the group with an extensive African distribution from Mauritania to Ethiopia. The mean dispersal rate of A. picticauda increased dramatically throughout the Pleistocene, and a Bayesian skyride analysis supports exponential population growth over this same time period. A comparison of genetic diversity across different loci and species suggests that A. lebretoni experienced a mitochondrial selective sweep that has caused a deficit of variation at this locus in relation to nuclear loci.     

Reproduction,predation, sexual dimorphism and diet in Agama anchietae (Reptilia: Agamidae) from Namibia

Agama anchietae is one of eight species of agama found in Namibia, its distribution range in the upper half of the country covers desert, Karoo and savannah type biomes and overlaps with that of some of its congeners. Here, we describe its sexual dimorphism, reproductive traits, predation, diet and nematode infection, and compare and contrast each aspect among the three biomes as well as to published findings for three other Namibian congenerics, Agama etoshae, Agama aculeata aculeata and Agama planiceps planiceps. Interesting similarities and differences were found among the biomes as well as with the three congenerics. Our hypothesis that the aspects studied in A. anchietae would be more in line with those of A. a. aculeata and A. etoshae, with which it shares similarities in body colouration, social organisation and microhabitat utilisation, was only partially confirmed. This cautions against using morphological and ecological similarities between agamas as proxies for making life-history strategy inferences.     

Kinematics of prey capture and chewing in the lizard Agama agama (squamata: Agamidae)

High speed video recordings (200 fields per second) of prey capture and food processing in Agama agama permit the identification of strikes, chews and transport movements. Ten variables from strike movements and seven variables from chewing sequences are digitized; transport movements are inspected only. Univariate and multivariate statistical analyses disclose significant interindividual differences for three variables (maximum gape distance, maximum head angle, and maximum throat distance); but neither these nor principal components analysis show differences between strikes and chews for any of the gape change and hyoid depression variables. However, strikes and chews obviously differ in tongue protrusion and body movements. Chewing may be divided into four stages, comparable to those of transport cycles of other lizards and the generalized tetrapod model. Transport differs from chewing by having a shorter power stroke and relatively more cranial and less jaw movement. The kinematics of feeding in Agama agama are compared with those of other lizards studied previously.     

Characteristic features of the sonicated DNA of Agama agama agama L. (Reptilia,Agamidae) on hydroxyapatite columns,using mouse DNA as a reference

Hydroxyapatite column chromatography has been used to study some properties of the extensively sheared DNA of the Rainbow lizard, Agama agama agama. Reassociation studies show that the genome has a Cot_1/2 of 370. Approximately 15% of the genome is highly repetitive in nature. This repetitive fraction is resolved into thermally stable and less stable fractions. The stable fraction has a base composition of 47% GC, higher than the 40.2% GC for the native DNA. This stable fraction is believed to be of recent origin.Chromatography of the total DNA of the lizard with linear gradients of phosphate buffer containing 1 M urea resolves it into two components which were shown by thermal fractionation, also in the presence of 1 M urea, to vary in base composition. This behaviour may be characteristic of reptilian genomes and may be used as a basis for studying the structural organisation of the reptilian genome.     

Characterization of gastrointestinal chitinase in the lizard Sceloporus undulatus garmani (Reptilia: Phrynosomatidae)

Most studies on chitinase activity in lizards have been concerned with Palaearctic (European) and Laurasian (Middle Eastern and Asian) taxa. Several genera of Old World lizards, Anguis, Uromastix, Chamaeleo and Lacerta, have been shown to possess chitinolytic activity. To date, only one New World lizard, Anolis carolinensis, has been reported to exhibit chitinolytic activity. In the present study, chitinase activity was characterized in a second New World taxon, Sceloporus undulatus garmani, a New World, phrynosomatid lizard. Chitinolytic activity was measured by incubating tissue extracts with a radioactive chitin substrate, acetyl-[H³]chitin and determining acid soluble radioactivity as an estimate for chitin hydrolysis. Chitinolytic activity was present in stomach, small intestine and pancreas extracts, with the stomach and pancreas having the highest specific activities. Chitinolytic activity was higher at pH 4.5 than at pH 7.5. The stomach chitinase is immunologically similar to the gastric chitinase previously described for rainbow trout. Western blot analysis showed anti-chitinase cross-reactivity in the extracts of the stomach, but no cross-reactivity in the pancreatic or intestinal extracts, suggesting different isoforms of chitinase. There was no detected lysozyme activity (less than 0.01 mg/ml lysozyme) present in the extracts of the stomach, small intestine and pancreas. The localization of chitinolytic activity in S. u. garmani is in agreement with earlier reptilian reports on the distribution of chitinase.     

Conservation genetics of the endangered grassland earless dragon Tympanocryptis pinguicolla (Reptilia: Agamidae) in Southeastern Australia

The grassland earless dragon, Tympanocryptis pinguicolla, islisted as endangered throughout its range. A recent taxonomic studybased on both morphological and allozyme data elevatedpinguicolla from a subspecies of T. lineata to fullspecies status, but the allozyme data showed considerabledifferentiation among pinguicolla populations. To investigatethe magnitude and nature of these differences with an independent dataset, we targeted key pinguicolla populations and sequenced anapproximately 900 base pair DNA fragment of the mitochondrial genomethat includes half of the ND4 gene and three tRNA genes. We obtainedsequence data from 21 individuals drawn from the three T.pinguicolla populations, included representatives of two otherTympanocryptis species and used an Amphibolurusspecies as an outgroup. Seven mitochondrial haplotypes were found amongthe 21 T. pinguicolla samples – two in the AustralianCapital Territory (ACT) and five in the Cooma region, Phylogeneticsignal in the data sets was extremely strong and a variety ofphylogenetic analyses of the data all resulted in the same single fullyresolved tree. There are 37 unique differences in the ND4 gene betweenthe ACT and Cooma populations. This translates into genetic differencesof between 5.76% and 6.23% between the two populations. Incomparison to studies on other reptile groups in which the same fragmentof DNA was used, the differences found between the ACT and Coomapopulations are more in line with species-level differences thandifferences within a single species and suggests that these populationsshould be considered separate taxonomic units.     

Distribution and Environmental Suitability of the Smallscaled Rock Agama,Paralaudakia microlepis （Sauria： Agamidae） in the Iranian Plateau

Predictive potential distribution modeling is of increasing importance in modern herpetological studies and determination of environmental and conservation priorities. In this article we provided results of analysis and forecasts of the potential distribution of smallscaled rock agama Paralaudakia microlepis （Blanford, 1874） using the distribution models through Maxent （www.cs.princeton.edu/- schapire / maxent）. We made an attempt for comparison of input of bioclimatic factors and characteristics of biotope distribution for three species of genus Paralaudalda. Constructed model identified dissemination of Paralaudakia microlepis enough performance （AUC = 0.972 with dispersion 0.003）. According to the map constructed, the most suitable habitats of smallscaled rock agama Paralaudakia microlepis are located in southern and eastern Iran, the west of central Pakistan and southeastern Afghanistan.     

Purification and kinetic properties of skeletal muscle lactate dehydrogenase from the lizard Agama stellio stellio

Lactate dehydrogenase isoenzyme LDH-5 (M4) was purified to homogeneity from the skeletal muscle of lizard Agama stellio stellio as a poikilothermic animal, using colchicine-Sepharose chromatography and heat inactivation. The purified enzyme showed a single band after SDS-PAGE, corresponding to a molecular weight of 36 kD. The K _m values for pyruvate, NADH, lactate, and NAD⁺ were 0.020, 0.040, 8.1, and 0.02 mM, respectively. Pyruvate showed maximum activity at about 180 M, with a decline at higher concentrations. The enzyme was stable at 70°C for 30 min, but was rapidly inactivated at 90°C. The optimum pH for the forward reaction (pyruvate to lactate) was 7.5, and for the reverse reaction (lactate to pyruvate) was 9.2. Oxalate, glutamate, Cu²⁺, Co²⁺, Mn²⁺, and Mg²⁺ were inhibitory in both forward and reverse reactions.     

Population fragmentation in the southern rock agama, Agama atra: more evidence for vicariance in Southern Africa

Mitochondrial DNA sequence data derived from two genes were used to infer phylogeographical relationships between 13 Agama atra populations. Three distinct geographical assemblages were found among the lizard populations. The first occurs in southern Namibia, the second is restricted to the western dry arid regions of South Africa, whereas the third is distributed throughout the more mesic southern and eastern parts of the subcontinent. Geographically structured differences among populations within Agama clades are probably the result of dispersal and historic isolations among populations. At the broader scale, there were marked congruences between the Agama genetic discontinuities and those described previously in other rock-dwelling vertebrates such as Pronolagus rupestris and Pachydactylus rugosus. This suggests vicariance, probably as a response to natural climatic changes during the past three million years.     

Genetic variation and climatic selection in the lizard Agama stellio in Israel and Sinai

Summary Allozymic variation in proteins encoded by 25 loci was analyzed electrophoretically in 242 adult specimens representing nine populations of the Levantine lizard, Agama stellio, comprising two subspecies: the Mediterranean A. stellio subsp., and the desert-inhabiting A. stellio brachydactyla from the Negev and Sinai. Likewise, four body traits were measured in the same populations. The nine populations were sampled along a general southward transect of increasing aridity. Agama stellio is above average in both polymorphism, P, and heterozygosity, H, as compared to other reptiles and vertebrates in general, displaying levels of genetic variation characterizing habitat generalist vertebrates. In the populations studied no fixation of alternative alleles was found in any of the 25 loci: rather the commonest allele was either fixed or predominated in 23 of 25 loci examined. Eleven loci (44%) were monomorphic in all nine populations. However, of the remaining 14 polymorphic loci, eight were strongly polymorphic displaying distinct genetic differentiation between populations. Genetic diversity (indexed by P and H) displayed geographic variation and was slightly higher in A.s. brachydactyla than in A. stellio subsp. Nevertheless, genic similarity between populations was high. A statistically significant amount of morphological variation between localities was found for all body characters. In general, body size increased southwards and eastwards with aridity.Selection at some loci is suggested by significant deviation from Hardy-Weinberg expectations and possibly by excess heterogeneity of effective inbreeding coefficients, F_e. Furthermore, allozymic variation at seven loci (Ldh-1, Idh-1, 6-Pgd-1, Aat-1, Pgm-2, Pept-1, and Trf) and geographic variation in body size and weight were significantly correlated with, and predictable by, climatic variables, primarily by water availability and secondarily by temperature. Finally, allozymic and morphological variations were partly correlated.The spatial patterns and ecological correlates of genic and morphological variations in Agama stellio in Israel and Sinai suggest that at least some proteins and body size differentiate geographically and appear to be adaptive, presumably with respect to factors affecting the availability of water.     

Phylogeny of North African Agama lizards (Reptilia: Agamidae) and the role of the Sahara desert in vertebrate speciation

The origin of Saharan biodiversity is poorly understood, in part because the geological and paleoclimatic events that presumably shaped species diversity are still controversial, but also because few studies have explored causal explanations for the origin of Saharan diversity using a phylogenetic framework. Here, we use mtDNA (16S and ND4 genes) and nDNA (MC1R and CMOS genes) to infer the relationships and biogeographic history of North African agamas (genus Agama). Agamas are conspicuous, diverse and abundant African lizards that also occur in the Saharan xeric and mesic environments. Our results revealed the presence of three Agama lineages in North Africa: one Afrotropical, one Sahelo-Saharan, and one broadly distributed in North Africa and mainly Saharan. Southern Mauritania contains the highest known diversity, with all three lineages present. Results suggest that agamas colonized the Sahara twice, but only one lineage was able to radiate and diversify there. Species in the Saharan lineage are mostly allopatric, and their splitting, genetic diversity and distribution are greatly explained by mountain ranges. One species in this lineage has colonized the Mediterranean climatic zone (A. impalearis), and another one the Sahel savannah (A. boueti). The other lineage to colonize the Sahara corresponds to A. boulengeri, an eminently Sahelian species that also inhabits Saharan mountain ranges in Mauritania and Mali. Phylogenetic analyses indicate that allopatric montane populations within some currently recognized species are also genetically divergent. Our study therefore concludes that vicariant speciation is a leading motor of species diversification in the area: Inside the Sahara, associated to mountain-ranges isolated by dune seas and bare plains; outside, associated to less harsh climates to the North and South. Paleoclimatic oscillations are suggested as causal explanations of the vicariant distribution and origin of species. Agamas are thought to have colonized northern Africa during wet periods, with subsequent dry periods fragmenting species distribution and leading to allopatric populations associated to milder and wetter climates in the Mediterranean, Sahel, and in Saharan mountains, in an island-model fashion. Finally, our results support the synonymization of A. castroviejoi with A. boueti, the reciprocal monophyly of all other North African agamas, and suggest one candidate species within A. boulengeri.     

Climate change drives speciation in the southern rock agama (Agama atra) in the Cape Floristic Region, South Africa

Aim Vicariance has played a major role in the evolution of the southern rock agama, Agama atra (Reptilia: Agamidae), and it is hypothesized that habitat shifts will affect small‐scale patterns of gene flow. The Cape Floristic Region (CFR) is known for high levels of diversity and endemism; thus we set out to investigate whether genetic structuring of CFR populations of A. atra corresponds to regional environmental shifts. Location Cape Fold Mountains and the Cape Floristic Region of South Africa. Methods The phylogeographical structure of 116 individuals of A. atra was determined by making use of 988 characters derived from two mitochondrial DNA fragments (control region and the NADH dehydrogenase subunit 2 coding region, ND2). Most animals originated from the CFR, but to gain a better understanding of the processes and patterns of dispersal within the species, 17 additional specimens from outside the CFR were also included and analysed in a phylogenetic context. Results Parsimony and Bayesian analyses revealed four distinct CFR clades (Cape clades) associated with geography. Phylogenetic analyses suggest that populations of A. atra in the CFR region are not entirely isolated from other populations, because some individuals from outside the CFR were nested within the four main Cape clades. The combined mitochondrial DNA data set revealed 59 distinct haplotypes in the CFR. Analysis of molecular variance (amova ) confirmed the high degree of genetic structure among the Cape clades, with more than 75% of the genetic variation found among the geographical areas. A spatial amova suggested that a ‘central clade’ originally defined as one of the four Cape clades may contain several additional populations. The main cladogenesis of A. atra within the CFR is estimated to have taken place c. 0.64–2.36 Ma. Main conclusions Agama atra shows at least four distinct genetic provinces within the CFR region, which highlights the conservation importance of this biologically diverse area. The dates of separation among the clades coincide well with the documented Pleistocene climate fluctuations, which might have contributed towards the isolation among lineages; the congruent genetic structure of A. atra with other CFR taxa further supports vicariance as a main isolating factor.     

Conservation genetics and species status of an endangered Australian dragon, <Emphasis Type="Italic">Tympanocryptis pinguicolla</Emphasis> (Reptilia: Agamidae)

We present a phylogenetic and morphological study of the grassland earless dragon, Tympanocryptis pinguicolla, an endangered habitat specialist that occurs in a few isolated populations in eastern Australia. Tympanocryptis pinguicolla occurred historically in Victoria in south-eastern Australia, but has not been seen since 1990, and current populations are known in New South Wales and Canberra in south-eastern Australia. Recently, new populations identified as T. pinguicolla were discovered on the Darling Downs, Queensland. Translocation of individuals between these populations has been suggested as a conservation management strategy to maintain genetic diversity. To address this issue, we undertook a phylogenetic study of all major populations of T. pinguicolla using a 1838 bp region of mitochondrial DNA, incorporating ND1, ND2, COI and eight tRNA genes. We incorporated specialized degraded-DNA techniques to amplify DNA from historical museum specimens, as no extant tissue was available for Victorian populations. Our results, which include morphological analysis, provide convincing evidence that populations currently identified as T.␣pinguicolla do not comprise a monophyletic species, as the populations from the Darling Downs are more closely related to T. tetraporophora than to T. pinguicolla. In addition, we find that there is a significant level of haplotype divergence between populations of T. pinguicolla, indicating that these lineages separated at least 1.5 mya. Our results suggest translocation may not be an appropriate management strategy and our findings that Darling Downs populations are not T.␣pinguicolla will significantly influence the conservation management of this species in Queensland.     

A phylogeny of Chinese species in the genus Phrynocephalus (Agamidae) inferred from mitochondrial DNA sequences

We investigated the phylogenetic relationships among most Chinese species of lizards in the genus Phrynocephalus (118 individuals collected from 56 populations of 14 well-defined species and several unidentified specimens) using four mitochondrial gene fragments (12S rRNA, 16S rRNA, cytochrome b, and ND4-tRNA(LEU)). The partition-homogeneity tests indicated that the combined dataset was homogeneous, and maximum-parsimony (MP), neighbor-joining (NJ), maximum-likelihood (ML) and Bayesian (BI) analyses were performed on this combined dataset (49 haplotypes including outgroups for 2058bp in total). The maximum-parsimony analysis resulted in 24 equally parsimonious trees, and their strict consensus tree shows that there are two major clades representing the Chinese Phrynocephalus species: the viviparous group (Clade A) and the oviparous group (Clade B). The trees derived from Bayesian, ML, and NJ analyses were topologically identical to the MP analysis except for the position of P. mystaceus. All analyses left the nodes for the oviparous group, the most basal clade within the oviparous group, and P. mystaceus unresolved. The phylogenies further suggest that the monophyly of the viviparous species may have resulted from vicariance, while recent dispersal may have been important in generating the pattern of variation among the oviparous species.     

Function and evolution of the frill of the frillneck lizard, Chlamydosaurus kingii (Sauria: Agamidae)

Relative to body size, the frill of the Australian agamid lizard Chlamydosaurus kingii is one of the largest and most spectacular display structures seen in any animal species. More than 300 hours observation of free-ranging lizards, combined with data on museum specimens, revealed that the frill is used primarily for intraspecific communication and predator deterrence. Earlier hypotheses on alternative uses for the frill (gliding, food storage, thermoregulation or auditory enhancement) are not supported. The folded frill may also enhance camouflage, but this is probably a fortuitous effect rather than an adaptation.
Male frillnecks frequently display and fight during the mating season. Male displays are highly stereotyped, and involve repeated partial erection of the frill, head-bobbing, tail-lashing, and waving of forelimbs. Both males and females erect the frill during social encounters, and in response to potential predators. Males grow larger than females and have larger heads than do females at the same body size, but no dimorphism is apparent in the relative size of the frill. The extreme development of the display structure in this species may be due to general allometric relationships, as well as to ecological features that have intensified the action of sexual selection in Chlamydosaurus.     

Temperature effects on oxygen consumption of two nocturnal geckos,Ptyodactylus hasselquistii (Donndorff) andBunopus tuberculatus (Blanford) (Reptilia: Gekkonidae) in Saudi Arabia

Summary Oxygen consumption rates of the lizardsPtyodactylus hasselquistii (adult and subadults) andBunopus tuberculatus (adult) were determined in relation to ambient temperatures ranging from 10 to 35°C using a double-chamber, volumetric closed system. The metabolic rate-temperature curves for both species were triphasic and similar in shape, but O₂ consumption differed between species.The low thermal dependence at temperatures between 15 and 25°C, common to both species, was correlated with the lizards' dual mode of thermoregulatory activity and ecology.     

Chromosomal variation in the scincid genus Mabuya and its arboreal relatives (Reptilia: Squamata)

Karyotypes of four East and Southeast Asian species of the genus Mabuya and representatives of three arboreal genera considered to be closely related to the genus (Apterygodon, Dasia and Lamprolepis) are examined. Mabuya rugifera and M. rudis possess 2n=32 karyotypes, whereas M. longicaudata lacks one small chromosome pair, which makes its diploid number 30. The karyotype of M. macularia quadrifasciata from southern Thailand differs from any known scincid karyotypes, including a previously reported karyotype of the conspecific Indian population, in exhibiting a high diploid number (38) and a gradual change in size from large to small chromosomes. This suggests that M. macularia may consist of more than one biological species. Karyotypes of Apterygodon vittatus, Dasia olivacea and Lamprolepis smaragdinus, while exhibiting a close similarity to most Mabuya karyotypes, suggest the occurrence of slight rearrangements involving either the deletion of two small chromosome pairs (A. vittatus), or the change of centromeric positions in medium and small chromosomes (D. olivacea and L. smaragdinus).