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Urbanisation is a major driver of habitat transformation that alters the environmental conditions and selective regimes of the habitats where it occurs. For species inhabiting urban habitats, such alterations can facilitate adaptive responses in their phenotypes, including their morphology. Quantifying potential responses could provide important information for assessing adaptation to urbanisation and may also be relevant to their conservation. Previous studies on African dwarf chameleons (Bradypodion) have shown these lizards to have remarkable adaptive capacity in response to different habitats (e.g. closed canopy habitats vs. open canopy habitats). Several of these species exploit urban habitats, but the extent to which populations are adapting to urban environments has only recently started to receive attention. In this study, we quantify differences in body size and body condition between urban and natural populations of five species of dwarf chameleons. For most comparisons, either females, males or both sexes from urban populations were longer, heavier and/or had better body condition than those from natural populations. In the remaining cases, there were no differences in these traits between populations. Our findings conform with the emerging paradigm that urbanisation positively correlates with enhanced lizard body sizes and condition, although the reasons for this may be complex. Nevertheless, our data provide an avenue for future research into investigating the potential factors (e.g. food supply, predation risk, etc.) that facilitate the trends we observed. [ABSTRACT FROM AUTHOR]

Background: The cornea of various vertebrate is considered a major part in the glop, which acts as a powerful lens, providing a sharp retinal image, and meantime acts as an excellent defensor for other corneal layers. Results: The four reptilian families [Scincidae (Chalcides ocellatus); Chamaeleontidae (Chameleon chameleon); Cheloniidae (Chelonia mydas) and Testudiniae (Testudo kleinmanni)] investigated in the current study were gathered across Egypt. After being taken out of the orbit, the cornea under inquiry was ready for light, specific stain and scanning electron microscopy. The epithelium, stroma, and endothelium are the three corneal layers that are common to all four species of reptiles. All other species lack Bowmen's and Descemet's membranes, with the exception of C. ocellatus and T. kleinmanni. The latter layers of Chalcides ocellatus display a strong affinity for Periodic Acid Schiff stain. Epithelial cells with a variety of forms, from hexagonal to atypical polygonal cells, cover the outer corneal surface. These epithelial cells are coated in short microplicae, microvilli, and microholes of varied diameters. There are a few blebs scattered around their surface. Conclusion: The current study concluded that various habitats have various significant effects on the cornea's microstructure characteristics and its physiological trends to accommodate different environmental surroundings. [ABSTRACT FROM AUTHOR]

Climate and land use changes are eroding biodiversity globally, and reptiles are highlighted as being particularly susceptible. In South Africa, global changes threaten the persistence of an assemblage of dwarf chameleons (Bradypodion) located in a biodiversity hotspot. We used ecological niche modelling to assess the combined effect of climate change and habitat transformation on these species and assessed their susceptibility in a vulnerability framework under optimistic and pessimistic change scenarios. Although our models showed a gain in suitable climatic space for all coastal species in some scenarios, considerable losses were predicted for most species under the most pessimistic change scenarios. Bradypodion ngomeense, for example is predicted to incur a complete loss of climatic suitability by 2050. The vulnerability framework predicts inland species to be more adversely affected by climate change than coastal species. However, no species show resilience to the combined effects of climate change and habitat transformation. Our models predicted a loss of climatically suitable habitat for most species in protected areas. These findings highlight the importance of a protected area network design to remain a step ahead of these anticipated changes. [ABSTRACT FROM AUTHOR]

Urbanisation creates novel environments, not only through (abiotic) microhabitat alterations, but also due to changes in (biotic) inter- and intraspecific interactions. Where sheltering sites in urban habitats are limited, intra or interspecific interactions may increase, resulting in increased competition and changes in predation risk in urban areas compared to natural habitats. The Knysna Dwarf Chameleon (Bradypodion damaranum) occurs in both urban and natural settings, is extremely ornamented, and individuals have been observed with multiple wounds and scars. We therefore hypothesised that urban populations may have adapted to the physical features of urban habitats, and that this would be detectable through ornament size and bite force, as well as the presence of scarring. We quantified these traits from urban and natural populations from two separate localities (the towns of George and Knysna, South Africa). Our results showed that female and male B. damaranum from urban populations had a higher number of injuries and that urban males were more likely to be injured than males from natural habitats. Bite force was only recorded at one locality (Knysna), but both sexes in urban habitats had higher bite force when accounting for casque height as compared to those from the natural habitats. Urban chameleons also had less developed ornamentation but wider and/or higher heads compared to populations in natural habitats. Urban habitats had significantly lower tree density than natural habitats, and this may be a factor in driving the morphological differences between populations, whereby reduced ornamentation confers an advantage for remaining cryptic to predators in the open habitat but compromises the ability for signalling conspecifics with encounters escalating to physical contests. [ABSTRACT FROM AUTHOR]

A complete and high-quality reference genome has become a fundamental tool for the study of functional, comparative, and evolutionary genomics. However, efforts to produce high-quality genomes for African taxa are lagging given the limited access to sufficient resources and technologies. The southern African dwarf chameleons (Bradypodion) are a relatively young lineage, with a large body of evidence demonstrating the highly adaptive capacity of these lizards. Bradypodion are known for their habitat specialization, with evidence of convergent phenotypes across the phylogeny. However, the underlying genetic architecture of these phenotypes remains unknown for Bradypodion , and without adequate genomic resources, many evolutionary questions cannot be answered. We present de novo assembled whole genomes for Bradypodion pumilum and Bradypodion ventrale , using Pacific Biosciences long-read sequencing data. BUSCO analysis revealed that 96.36% of single copy orthologs were present in the B. pumilum genome and 94% in B. ventrale. Moreover, these genomes boast scaffold N50 of 389.6 and 374.9 Mb, respectively. Based on a whole genome alignment of both Bradypodion genomes, B. pumilum is highly syntenic with B. ventrale. Furthermore, Bradypodion is also syntenic with Anolis lizards, despite the divergence between these lineages estimated to be nearly 170 Ma. Coalescent analysis of the genomic data also suggests that historical changes in effective population size for these species correspond to notable shifts in the southern African environment. These high-quality Bradypodion genome assemblies will support future research on the evolutionary history, diversification, and genetic underpinnings of adaptation in Bradypodion. [ABSTRACT FROM AUTHOR]

The livers of reptiles are being studied as a model for the link between the environment and hepatic tissue. There have been few investigations on the histology of reptile livers, and very few or no studies have examined the histology of liver of veiled chameleon (Chamaeleo calyptratus). This paper describes the histomorphological, histochemical and ultrastructural characterization of the liver of veiled chameleons in southern Saudi Arabia. Seven Chamaeleo calyptratus were captured in the summer season in Abha City, Aseer region, southern Saudi Arabia. Chamaeleon liver samples were processed for histomorphology, histochemistry and ultrastructure analyses. Morphologically liver of Chamaeleo calyptratus was observed as a large dark brown organ with lighter speckles, which represent melanin deposits. It located at the ventral part of abdominal cavity forward of the stomach. Its dimensions approximately were 3.7 ' 2 cm. The liver was a bilobed organ divided into two lobes, right and left lobes. The right one was bigger than the others. The gallbladder was well developed and had an elongated shape, situated between the two lobes and contained the bile for the digestion. Microscopically, the liver was found to be covered by a thick layer of connective tissue, which formed the hepatic capsule. Hepatic parenchyma probably appeared in cross sections as hepatic glandular-like alveoli "acini" or follicular structures with various diameters, each acinus contains approximately four to six hepatocytes, surrounded by sinusoidal capillaries filled with abundant melanomacrophages, which are absent in birds and mammals. Melanomacrophages are common in the hepatic parenchyma's perisinusoidal areas, particularly near portal spaces. Hepatocytes are polyhedral or pyramidal with and mostly contained large, rounded nuclei mostly peripherally located, with prominent dark oval nucleoli. Some of nuclei are eccentric or central position. The cytoplasm appeared spongy or vacuolated and more eosinophilic when stained by hematoxylin-eosin and strongly reactive to PAS staining technique, indicating abundant glycogen content. The reticular fibers that surround hepatocytes, blood arteries, and sinusoids supported the hepatic parenchyma. The blood sinusoids are seen interspersed among hepatocytes of varying sizes. The sinusoidal lumen was bordered by flattened endothelial cells and includes elliptical nucleated erythrocytes and liver macrophages as phagocytes, which are also known as Kupffer cells. Branches of the portal vein, hepatic artery, small bile duct, and lymph vessels were detected in the hepatic portal area "tract" or triad which made up of connective. Hematopoietic tissue was observed in subcapsular region and portal triads. Ultrastructurally, the hepatocyte appeared polyhedric containing a single large rounded basal or eccentric vesicular nucleus with prominent nucleolus. Extensive network of rough endoplasmic reticulum (RER) often arranged in an array parallel to the nuclear membrane with many mitochondria, and Golgi apparatus were described. The cytoplasm contained glycogen granules, vesicles or vacuoles scattered throughout the cytoplasm especially at the apical region were reported. The bile canaliculi and the hepatic "Kupffer" cells were also discussed. This is the first study on the histological characterization of the healthy liver of Yemen veiled chameleon in southern Saudi Arabia. The findings reported here should be used as a reference to compare with the pathological abnormalities of the liver in this animal. [ABSTRACT FROM AUTHOR]

Biotremors are vibrations, usually surface waves along the boundary of a medium, produced by an organism. While substrate-borne vibrations are utilized by different reptile species, true conspecific communication via biotremors has not yet been demonstrated in lizards. Recent research revealed that the veiled chameleon (Chamaeleo calyptratus) produces biotremors. The prerequisites for any communication system are the ability of an organism to produce and detect a signal. We tested C. calyptratus behavioral responses to vibrations by placing them on a dowel attached to a shaker, emitting vibrations of 25, 50, 150, 300, and 600 Hz and compared their locomotory velocity before and after the stimulus. Adult chameleons exhibited a freeze response to 50 and 150 Hz, while juveniles exhibited a similar response to frequencies between 50 and 300 Hz. In a second experiment, chameleons were induced to produce biotremors via experimenter contact. These biotremors ranged in mean fundamental frequency from 106.4 to 170.3 Hz and in duration from 0.06 to 0.29 s. Overall, two classes of biotremors were identified, "hoots" and "mini-hoots," which differed significantly in mean relative signal intensity (−7.5 and −32.5 dB, respectively). Juvenile chameleons 2 months of age were able to produce biotremors, suggesting this behavior may serve a wide range of ecological functions throughout ontogeny. Overall, the data demonstrate that C. calyptratus can both produce and detect biotremors that could be used for intraspecific communication. [ABSTRACT FROM AUTHOR]

Arboreal chameleons must navigate a complex, three-dimensional landscape consisting of trees, bushes and/or grasses of various sizes. This complexity equates to the microhabitat of chameleons, that is, the branches upon which they perch and through which they move. Therefore, chameleons rely on their ability to grip perches available to them, and this is evident by their specialised adaptations such as their prehensile tail and their grasping hands and feet. To date, ecological studies of chameleons have relied on gathering data on perch use only at night because locating chameleons during the daytime is extremely difficult. However, the night-time perch represents the sleeping perch of individuals, and this is not necessarily reflective of overall diel perch use. Many other arboreal reptiles are constrained to using thin perches at night, but by day their microhabitat is more variable, using thicker branches, limbs or tree trunks. To assess whether this well-entrenched paradigm (night-time perch use being constrained to thin perches) also extends to fully arboreal chameleons, daytime and night-time perch diameters were measured for the Cape Dwarf Chameleon, Bradypodion pumilum, and were compared using analyses of variance statistical approaches. Neither perch diameters nor variance in perch diameters differed between the two photoperiods, and the variance in diameters of perches used was remarkably high. Despite this variance, there was a significant, positive relationship between body size and the diameter of perches used. Unlike other reptiles, the results show that for B. pumilum the night-time perch use is not different than diurnal perch use, and there appears to be a fairly wide range of perches used by chameleons of a given body size over both photoperiods. Nevertheless, the positive trend for chameleons of larger body sizes to choose larger perches than smaller chameleons implies that there are some upper and lower constraints for the diameters of perches used, possibly relating to their ability to effectively grip a range of perch sizes. [ABSTRACT FROM AUTHOR]

Previous molecular phylogenetic studies of pygmy chameleons have identified several cases of undescribed cryptic diversity of species, some of which have remained undescribed due to a lack of morphological information. Here, we combine descriptive morphology with principal component analysis, to quantify the overall morphological variation, and phylogenetic analysis to describe six new species of Rhampholeon from the Eastern Arc Mountains, including populations found in the Udzungwa, Rubeho, Nguru, Ukaguru, and Nguu Mountains. From our study we detected only limited morphometric variation between species. We distinguish the new species using genetics, combined with assessment of morphological features, and their geographical distribution. We highlight the threats to pygmy chameleons in East Africa from habitat change and exporting live specimens for the wildlife trade. Based on our understanding, we note a few species that we consider at risk of decline – mainly based on their narrow distribution and their apparent popularity in the export market. This study also further underlines the extraordinary biological value of the relatively small forest patches (less than 3000 km2 ) of the Eastern Arc, which contain more species of chameleons than any other area in mainland Africa. [ABSTRACT FROM AUTHOR]

The mechanisms that underpin ecological speciation, morphological convergence and the evolution of ecological morphotypes (ecomorphs) in squamates have allowed for a better appreciation of the speciation process in chameleons. In particular, attention has been drawn to several populations of chameleons (Sauria, Chamaeleonidae, Bradypodion) from the Cape Fold Mountains, South Africa. Previous work suggested that these populations are genetically divergent, but with strong similarities in phenotype. Using an integrative taxonomic approach that accounts for genetic diversity, habitat and morphology, three of these populations are described as species. One population is from an isolated forest patch and is genetically different at the species level, but morphologically similar to Bradypodion damaranum (Boulenger, 1887) from forested areas in the Knysna region. Although not sister species, the two are in the same clade and probably diverged through vicariance of the forest. Two other populations are from fynbos habitat in adjacent mountain ranges (Tsitsikamma/Langkloof/Kouga mountains and Baviaanskloof Mountains) and are also morphologically similar, but genetically divergent at the species level. These two species are not sister taxa and are not in the same clade yet have a virtually identical phenotype presumably as the result of convergent evolution for the fynbos habitat. Within the context of morphological taxonomy, these populations have been difficult to evaluate. However, when viewed in the context of ecological speciation, convergence and morphological conservatism, the species boundaries are apparent, allowing for them to be described as new taxa. [ABSTRACT FROM AUTHOR]

Background: Pronounced asymmetric changes in ocular globe size during eye development have been observed in a number of species ranging from humans to lizards. In contrast, largely symmetric changes in globe size have been described for other species like rodents. We propose that asymmetric changes in the three‐dimensional structure of the developing eye correlate with the types of retinal remodeling needed to produce areas of high photoreceptor density. To test this idea, we systematically examined three‐dimensional aspects of globe size as a function of eye development in the bifoveated brown anole, Anolis sagrei. Results: During embryonic development, the anole eye undergoes dynamic changes in ocular shape. Initially spherical, the eye elongates in the presumptive foveal regions of the retina and then proceeds through a period of retraction that returns the eye to its spherical shape. During this period of retraction, pit formation and photoreceptor cell packing are observed. We found a similar pattern of elongation and retraction associated with the single fovea of the veiled chameleon, Chamaeleo calyptratus. Conclusions: These results, together with those reported for other foveated species, support the idea that areas of high photoreceptor packing occur in regions where the ocular globe asymmetrically elongates and retracts during development. Key Findings: The eyes of the brown anole, Anolis sagrei, and veiled chameleon, Chamaeleo calyptratus undergo dynamic asymmetrical changes in ocular shape during development.In both species, asymmetric elongation and retraction of the ocular globe is associated with fovea morphogenesis.Pit formation and photoreceptor cell packing in the foveal area occur when the corresponding region of the ocular globe is retracting relative to adjacent regions. [ABSTRACT FROM AUTHOR]

This study aimed to describe the morphology, histology, and histochemistry of the kidneys and the sexual segment of the kidney (SSK) in Chamaeleo calyptratus (Yemen chameleons or veiled chameleons) collected during the active reproductive season. To achieve this objective, a total of 7 mature male Chamaeleo calyptratus were captured from their natural habitats from different areas in the Aseer region of Saudi Arabia and transferred to the reptilian laboratory where their kidneys were dissected out. Next, a morphological examination was conducted on the kidneys and the SSK was processed for light microscopic examinations with the primary focus placed on the morphology and histology of the SSK. The results of the study showed that Chamaeleo calyptratus possess two, reddish-brown, attenuated kidneys divided into lobes and lobules (lobulated). The histological study showed that the chameleons had no distinct limits between the cortex and medulla of the kidneys. In general, similar with other reptiles, this lizard demonstrated that the kidneys have few nephrons, do not show any nephron loop (loop of Henle), and display few glomeruli. The nephron is generally composed of standard components: renal corpuscle, glomerulus surrounded by a double-walled, the glomerular capsule (Bowman's capsule) and renal tubules (six renal tubular segments differentiated as the ciliated neck segment [between the glomerulus and the proximal segment], proximal segment, ciliated intermediate segment instead of nephron loop that connects proximal and distal, distal segment, terminal segment or sexual segment, and all segments emptying into the collecting ducts. The epithelial tissues lining the lumen of these segments vary from simple cuboidal cells to columnar and tall columnar cells in the SSK. Mature male Chamaeleo calyptratus possess hypertrophied parts of the distal renal segments, which are called the SSK. Histologically, the active SSK consists of simple tall columnar epithelial cells with rounded basal nuclei with clear centralized nucleoli and numerous apical coarse secretory granules which are released from the cells by an apocrine process. Histochemically, the secretory granules stain positively for proteins with mercuric bromophenol blue and react intensely to periodic acid-Schiff (PAS) for neutral carbohydrates. This is the first report about the histology of the SSK of the Chamaeleo calyptratus, and this study adds to the knowledge of the reproductive biology, biodiversity, and reproductive strategies of chameleons. Further studies are required to investigate the ultrastructure of the kidneys and SSK. [ABSTRACT FROM AUTHOR]

Fluid therapy selection is an important consideration for managing hemodynamically unstable patients. When working with reptiles, limited information is available for species-specific osmolality. A further understanding of reptile fluid balance and plasma osmolality is needed to select the most appropriate fluid for each situation. To date, osmolality has not been reported in a chameleon. Blood was collected from the ventral tail vein of 12 veiled chameleons (Chamaeleo calyptratus) and 12 panther chameleons (Furcifer pardalis) to measure plasma osmolality using an osmometer and to measure sodium, potassium, glucose, and uric acid concentrations using a standard chemistry analyzer. The chemistries were used to calculate osmolality using seven different formulas. The osmometer measured osmolalities in the veiled and panther chameleons were 330.5 mOsm/kg (range: 285–346.5 mOsm/kg) and 308.0 mOsm/kg (294–358.5 mOsm/kg), respectively. Bland–Altman plots were used to assess the level of agreement between these measured osmolalities and the seven calculated osmolalities. There was poor agreement between the measured and calculated osmolalities. Multiple linear regression was used to develop a species-specific equation for calculated osmolality; this was useful for veiled chameleons (osmolality = 2.098 [Na+]), but not panther chameleons. When comparing the measured osmolalities of these chameleons to other reptiles, there were significant differences (P < 0.05) between all groups, except veiled chameleons and green iguanas (Iguana iguana). The results of this study suggest that plasma osmolality should be considered species-specific in reptiles, and that an osmometer is the preferred method for measuring osmolality in veiled and panther chameleons. [ABSTRACT FROM AUTHOR]

The data presented in this paper stand as supplementary information of the associated article “Karyological characterization of the common chameleon (Chamaeleo chamaeleon) provides insights on the evolution and diversification of sex chromosomes in Chamaeleonidae” [1]. This work provides (i) raw experimental data on the karyology of the common chameleon Chamaeleo chamaeleon and (ii) the results of bioinformatic analysis on sex-specific and repeated DNA sequences found in the same species. The karyological information here presented includes traditional staining method (Giemsa staining) and sequential C-banding + fluorochromes performed on Tunisian samples of the species. The sequence data include the alignments of the isolated DNA sequences with homologous sequences found in squamate Short Read Archives (SRAs) and the results of searches in public nucleic acid databases.

Coccidia are common endoparasites in reptiles, especially lizards. Within this class Choleoeimeria spp. infections are rarely detected, but they may have a high pathogenic potential and treatments are often unsuccessful. A retrospective study was performed evaluating the prevalence of Choleoeimeria in fecal samples from lizards submitted for routine examination to a diagnostic laboratory in Germany. Between 2013 and 2014, 1.5% (n = 24/1,621; 95% confidence interval [CI]: 1.0–2.2%) of coprological samples from different lizard species tested positive for Choleoeimeria oocysts using a fecal flotation technique. This prevalence was similar to data obtained 10 yr earlier at the same laboratory. Infected species included central bearded dragons (Pogona vitticeps), collared lizards (Crotaphytus collaris), unclassified agamids, monitors, one horned tree lizard (Acanthosaura sp.), one gecko, one common bluetongue (Tiliqua scincoides), and one chameleon. Different treatments (toltrazuril in varying intervals or trimethoprim and sulfonamide) in combination with strict environmental hygiene and disinfection with p-Chlor-m-Kresol did not impact fecal oocyst shedding for one juvenile Lawson's dragon (Pogona henrylawsoni). A new therapy approach using 10 mg/kg toltrazuril PO q 24 h for 3 days, with a repeat in 7 days, combined with 5 mg/kg clindamycin PO q 24 h for 7 days, finally resulted in negative oocyst shedding. Possible explanations for the challenging treatment of Choleoeimeria spp. are their localization in the gallbladder or the phylogenetical distance of the genus Choleoeimeria to the typical members of the family Eimeriidae. Further research is needed to increase our knowledge of these parasites and to develop an evidence-based treatment approach for diseased reptiles. [ABSTRACT FROM AUTHOR]

The obscure or dubious designation of the name-bearing type(s) and hence the type locality of three valid chameleon taxa, viz. Brookesia superciliaris , Calumma fallax and Trioceros schubotzi , is researched and clarified. It concerns type-material of the natural history museums of Berlin, London and Paris. In the appendix additional information as to the presence of name-bearing types in various museum collections is presented to amend the checklist of Glaw (2015). [ABSTRACT FROM AUTHOR]

Follicular atresia (FA) has been assumed to serve different functions in reptiles, e.g. helping to develop hierarchies, limiting clutch size, and regression of ovarian structures. Reproductive output is dependent on a balance between ovulations and FA. Excessive rates of FA may not only be detrimental for the survival of a population, but have also been associated with pathological conditions. In order to gain insights into the physiological and potentially pathological processes of FA, we performed a decriptive study on the morphological features of the ovaries in sexually mature female veiled chameleons (Chamaeleo calyptratus , VC). Of 60 clinically healthy female VC with continuous ovarian cycling and at least one confirmed cycle with FA over at least 1.5 years, 30 were selected for macroscopic evaluation of ovarian appearance and 7 were subjected to histology and immunohistology. While FA of previtellogenic follicles happened at a low rate, expected for a species with two germinal beds per ovary and polyautochronic reproductive pattern, atresia in the late vitellogenic stage affected entire generations of follicles, consequential to ovulatory failure. Histologically, no pathological processes were identified in any of the animals. Rather, three stages of FA (early, middle, late) were defined and vitellogenic follicles showed two distinct morphological types of FA: yolky and cystic. Yolky FA was found in 21/30 (70%) animals, while cystic FA co-occurred in 9/30 (30%) of the animals. • Follicular atresia occurs in previtellogenic and vitellogenic follicles. • Vitellogenic follicles show two distinct forms of atresia; yolky and cystic. • Cystic atresia is less frequent and shows a longer duration of resorption. • Veiled chameleons have two germinal beds per ovary. [ABSTRACT FROM AUTHOR]

Invasive reptiles cause global ecosystem damage and are difficult to control once established. Visual detection and manual capture are time consuming and largely ineffective at eradication, particularly for cryptic species. The Jackson's chameleon (Trioceros jacksonii xantholophus), native to eastern Africa, is popular in the global pet trade and has become established in several localities, including the Hawaiian Islands where it has escaped or been intentionally released into sensitive native forest habitat where it feeds on endangered species. Here we tested an orally delivered, chemical toxicant as a feasible management technique for this invasive lizard in Hawaii. We administered predetermined dosages of powdered acetaminophen to adult chamleoens and determined that the dosage necessary to achieve ≥95% mortality within 48 h across size classes was 2000 mg/kg, or 90 mg of acetaminophen for an adult average mass of 45 g. Since the liver is known to process acetaminophen in vertebrate taxa, we conducted post mortem histological examination of liver tissue for all specimens at the 48 h time point. Finally, we propose a testable mechanism for field delivery of this oral toxicant following behavioral trials. [ABSTRACT FROM AUTHOR]

Aim To investigate whether morphological variation in a continental radiation of lizards (Chamaeleonidae) was driven by ecological opportunity. Location KwaZulu-Natal, South Africa. Methods Chameleons from all morphotypes were genotyped ( n = 279) using 10 microsatellite and one mitochondrial marker ( n = 130). Genetic spatial structure was examined in a Bayesian framework and compared to ecomorphological forms, to identify distinct chameleon groups using a total evidence approach. Ecological niche modelling projected back to the Last Glacial Maximum and the Last Interglacial was used to make inferences regarding the processes that may have facilitated diversification through ecological opportunity. Results For the three inland groups, genetic and morphological evidence were in agreement suggesting these are candidate species. However, there was discordance in evidence for populations from coastal regions, although the different time-scales of the data allow us to make some inferences regarding this disparity. The microsatellite data suggest at least three independent origins of coastal chameleons, although all three clusters show the same ecomorph, which indicates convergence of phenotype in a similar environment. The species distribution models revealed high niche stability among inland groups, suggesting the presence of refugia for these chameleons; whereas the coastal niche is more dynamic and likely resulted in recent origins of these groups. Main Conclusions A dynamic climatic niche and corresponding vegetation shifts are likely to have shaped contrasting ecomorphological and genetic patterns within this continental radiation by creating ecological opportunity for the coastal chamleons. In contrast, inland groups are in climatically stable regions, and show concordance between lines of evidence, suggesting that niche stability has allowed for these chameleons to diverge genetically and phenotypically. [ABSTRACT FROM AUTHOR]

The distinctive features of the jaw apparatus in chameleons (hyperstreptostyly, amphikinetism reduction, transformation of the cranial roof into a 'casque,' the jugo-mandibular ligament, the shape and position of quadrate bones, and the structure of jaw adductors) emerged as adaptations for the refinement of the mechanism of prey capture by the tongue. The development of another group of features (loss of the epipterygoid, m. levator pterygoidei, and structures associated with the middle ear) was an indirect consequence of the adaptations listed above. The formation of a specialized mechanism for prey capture by the tongue played a role of a key innovation (macromorphosis) in the phylogeny of chameleons. The ontogenetic relationships between the aforementioned features of the jaw apparatus of the chameleons are adaptive correlations, and the evolutionary transformations of these correlations correspond to biological coordinations. The evolutionary mechanisms underlying the formation of correlation and coordination interrelations in the organism are considered. [ABSTRACT FROM AUTHOR]

Chameleon teeth develop as individual structures at a distance from the developing jaw bone during the pre-hatching period and also partially during the post-hatching period. However, in the adult, all teeth are fused together and tightly attached to the jaw bone by mineralized attachment tissue to form one functional unit. Tooth to bone as well as tooth to tooth attachments are so firm that if injury to the oral cavity occurs, several neighbouring teeth and pieces of jaw can be broken off. We analysed age-related changes in chameleon acrodont dentition, where ankylosis represents a physiological condition, whereas in mammals, ankylosis only occurs in a pathological context. The changes in hard-tissue morphology and mineral composition leading to this fusion were analysed. For this purpose, the lower jaws of chameleons were investigated using X-ray micro-computed tomography, laser-induced breakdown spectroscopy and microprobe analysis. For a long time, the dental pulp cavity remained connected with neighbouring teeth and also to the underlying bone marrow cavity. Then, a progressive filling of the dental pulp cavity by a mineralized matrix occurred, and a complex network of non-mineralized channels remained. The size of these unmineralized channels progressively decreased until they completely disappeared, and the dental pulp cavity was filled by a mineralized matrix over time. Moreover, the distribution of calcium, phosphorus and magnesium showed distinct patterns in the different regions of the tooth-bone interface, with a significant progression of mineralization in dentin as well as in the supporting bone. In conclusion, tooth-bone fusion in chameleons results from an enhanced production of mineralized tissue during post-hatching development. Uncovering the developmental processes underlying these outcomes and performing comparative studies is necessary to better understand physiological ankylosis; for that purpose, the chameleon can serve as a useful model species. [ABSTRACT FROM AUTHOR]

Alternative mating tactics in males of various taxa are associated with body color, body size, and social status. Chameleons are known for their ability to change body color following immediate environmental or social stimuli. In this study, we examined whether the differential appearance of male common chameleon during the breeding season is indeed an expression of alternative mating tactics. We documented body color of males and used computer vision techniques to classify images of individuals into discrete color patterns associated with seasons, individual characteristics, and social contexts. Our findings revealed no differences in body color and color patterns among males during the non-breeding season. However, during the breeding season males appeared in several color displays, which reflected body size, social status, and behavioral patterns. Furthermore, smaller and younger males resembled the appearance of small females. Consequently, we suggest that long-term color change in males during the breeding season reflects male alternative mating tactics. Upon encounter with a receptive female, males rapidly alter their appearance to that of a specific brief courtship display, which reflects their social status. The females, however, copulated indiscriminately in respect to male color patterns. Thus, we suggest that the differential color patterns displayed by males during the breeding season are largely aimed at inter-male signaling. [ABSTRACT FROM AUTHOR]

A new species of chameleon is described from the Livingstone and Udzungwa Mountains of Tanzania. The new species is morphologically most similar to Kinyongia vanheygeni. Furthermore, a single, short rostral appendage shows the species similarity to other Eastern Arc endemic Kinyongia species (e.g. K. uthmoelleri, K. oxyrhina, K. magomberae and K. tenuis). Females of all these species lack any rostral ornamentation and are all very similar morphologically. Males of the new species, on which the morphological diagnosis is based, can be distinguished from other Kinyongia by a shorter rostral appendage that bifurcates at the tip. They are easily distinguished from K. vanheygeni, otherwise the most similar species, by differences in head scalation and the length and shape of the rostral appendage. The new species is associated with montane rainforest and is known from only four forest fragments of which two are in the Udzungwa and two in the Livingstone Mountains. Phylogenetically, the new species is sister to K. tenuis and K. magomberae, which together, form a clade that also contains K. oxyrhina. The disjunct distribution of the new species, in the Livingstone and Udzungwa mountains, stretches across the 'Makambako Gap' which is a putative biogeographical barrier separating the distinct faunas of the Southern highlands and Eastern Arc Mountains. Evidence from this species however, points to potentially closer biological affinities between the Livingstone and Udzungwa mountains. [ABSTRACT FROM AUTHOR]

Salmonella can be present in the intestinal flora of captive reptiles without clinical disease or it can cause life threatening morbidity. The presence of certain species of Salmonella in reptiles is consistent with them being the source of contamination in some cases of human disease. Thus, Salmonella positive animals can be a potential public health concern even more when strains acquire resistance to antibiotics. The nature and extent of Salmonella harboured by different species of reptiles commonly kept in captivity are not known. The aims of this study were to analyse the incidence of Salmonella species in cloacae as an indicator of the intestinal flora in a cohort of healthy captive bred female veiled chameleons. A cloacal sample was taken from each of fifteen healthy captive bred, adult female veiled chameleons that were housed at a teaching and research clinic. Salmonella isolates were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry and positive cases were serotyped by slide agglutination test. Salmonella organisms were detected in 12 chameleons. Eighty percent of chameleons harboured 1 of 4 subspecies and serovars of Salmonella. All strains belonged to the species enterica, predominantly subspecies enterica (91.7 %) and were distributed among 4 different serovars: S. Ago (58.3 %), S. Blijdorp (16.7 %), S. Tennessee (16.7 %) and S. IV 45:g,z51:- (8.3 %). Antibiotic resistance to streptomycin was detected in one of 12 Salmonella strains: S. IV 45:g,z51:-. Our study extended the list of Salmonella found in healthy captive animals and included serovars S. Tennessee and S. IV 45:g,z51:- that have been associated with morbidity in humans. [ABSTRACT FROM AUTHOR]

Research on intraspecific aggression has typically focused on dominant individuals, but a better understanding of the consequences and mechanisms of agonistic encounters requires a balanced perspective that includes knowledge of subordinate animal behaviors. In contrast to signals of fighting ability, signals of submission are an understudied component of agonistic communication that could provide important insights into the dynamics, function, and evolution of intraspecific competition. Here, I use a series of staged agonistic trials between adult male veiled chameleons Chamaeleo calyptratus to test the hypothesis that rapid skin darkening serves as a submissive signal to resolve agonistic activity. Concordant with this hypothesis, I found that losing chameleons darkened over the course of aggressive trials while winners brightened, and the likelihood of darkening increased when individuals were attacked more aggressively. Additionally, I found that the degree of brightness change exhibited by individual chameleons was tied to both overall and net aggression experienced during a trial, with chameleons who received high levels of aggression relative to their own aggression levels darkening to a greater extent than individuals receiving relatively less aggression. Lastly, I found that aggression increased for losers and winners prior to the onset of darkening by the eventual loser but that both chameleons reduced aggression after the losing chameleon began to darken. Based on the theoretical prediction that signals of submission should be favored when retreat options are restricted, I suggest that limited escapability imposed by chameleon morphology, physiology, and ecology favored the evolution of a pigment-based signal of submission in this group. [ABSTRACT FROM AUTHOR]

Abstract: Qesem Cave is a unique Middle Pleistocene, hominin-bearing site in Israel that contains a rich microvertebrate accumulation. The microvertebrates are highly unusual in that half of them are from small reptiles, and most of the reptiles are chameleons, which are otherwise rare in the fossil record. Analysis of the lower vertebrate component shows uniform taphonomic characteristics: on average 17.6% of specimens show evidence of corrosion (the vast majority light), and specimen breakage is between 4.9 and 12.0%, depending on metric. Charring is negligible. Most species are small (body mass <60 g). These taphonomic attributes do not vary in the studied portion of the stratigraphic profile, nor do they systematically vary between taxa. Thorough study of all skeletal parts suggests that most individuals probably entered the cave as whole animals; the only exception is the large glass lizard, Pseudopus, which is represented mostly by the tail. These taphonomic data suggest a Barn Owl as the predominant accumulator. However, natural history observations on Barn Owls and chameleons are strongly at odds with this actualistic inference: Barn Owls are nowhere recorded as a major predator on chameleons. We argue that a focus on extant, especially European, populations could distort our understanding of their feeding biology and is vulnerable to counterexample. We propose a scenario that harmonizes actualism and natural history. We further identify a possible owl roost in Qesem Cave, the first time such a roost has been identified in a collapsed cave setting. These conclusions may have conservation implications for chameleons. They also suggest that the hearth adjacent to the microvertebrate concentration was situated in the twilight zone. [Copyright &y& Elsevier]

The recently erected chameleon genus Kinyongia currently includes 17 species, with the majority of this diversity occurring in montane regions of East Africa. Kinyongia adolfifriderici is one of only three species in the genus to occur in Central Africa, with numerous populations occurring from low- to high-elevation forests of the Albertine Rift. Recent fieldwork in the Lendu Plateau in northeastern Democratic Republic of the Congo (DRC) led to the discovery of a population of chameleons that is significantly larger than and morphologically distinct from the closely related species K. adolfifriderici, which was described from the lowland Ituri forest, DRC. Analyses of mitochondrial (16S and ND2) and nuclear (RAG1) DNA sequence data revealed that K. adolfifriderici is a complex of cryptic species. Herein, we describe the Lendu population as a new species, underscoring the endemism and conservation importance of this poorly known, unprotected montane region. [ABSTRACT FROM AUTHOR]

Background: One clade of Malagasy leaf chameleons, the Brookesia minima group, is known to contain species that rank among the smallest amniotes in the world. We report on a previously unrecognized radiation of these miniaturized lizards comprising four new species described herein. Methodology/Principal Findings: The newly discovered species appear to be restricted to single, mostly karstic, localities in extreme northern Madagascar: Brookesia confidens sp. n. from Ankarana, B. desperata sp. n. from Forê t d'Ambre, B. micra sp. n. from the islet Nosy Hara, and B. tristis sp. n. from Montagne des Français. Molecular phylogenetic analyses based on one mitochondrial and two nuclear genes of all nominal species in the B. minima group congruently support that the four new species, together with B. tuberculata from Montagne d'Ambre in northern Madagascar, form a strongly supported clade. This suggests that these species have diversified in geographical proximity in this small area. All species of the B. minima group, including the four newly described ones, are characterized by very deep genetic divergences of 18-32% in the ND2 gene and >6% in the 16S rRNA gene. Despite superficial similarities among all species of this group, their status as separate evolutionary lineages is also supported by moderate to strong differences in external morphology, and by clear differences in hemipenis structure. Conclusion/Significance: The newly discovered dwarf chameleon species represent striking cases of miniaturization and microendemism and suggest the possibility of a range size-body size relationship in Malagasy reptiles. The newly described Brookesia micra reaches a maximum snout-vent length in males of 16 mm, and its total length in both sexes is less than 30 mm, ranking it among the smallest amniote vertebrates in the world. With a distribution limited to a very small islet, this species may represent an extreme case of island dwarfism. [ABSTRACT FROM AUTHOR]

Aim East Africa is one of the most biologically diverse regions, especially in terms of endemism and species richness. Hypotheses put forward to explain this high diversity invoke a role for forest refugia through: (1) accumulation of new species due to radiation within refugial habitats, or (2) retention of older palaeoendemic species in stable refugia. We tested these alternative hypotheses using data for a diverse genus of East African forest chameleons, Kinyongia. Location East Africa. Methods We constructed a dated phylogeny for Kinyongia using one nuclear and two mitochondrial markers. We identified areas of high phylogenetic diversity (PD) and evolutionary diversity (ED), and mapped ancestral areas to ascertain whether lineage diversification could best be explained by vicariance or dispersal. Results Vicariance best explains the present biogeographic patterns, with divergence between three major Kinyongia clades (Albertine Rift, southern Eastern Arc, northern Eastern Arc) in the early Miocene/Oligocene (> 20 Ma). Lineage diversification within these clades pre-dates the Pliocene (> 6 Ma). These dates are much older than the Plio-Pleistocene climatic shifts associated with cladogenesis in other East African taxa (e.g. birds), and instead point to a scenario whereby palaeoendemics are retained in refugia, rather than more recent radiations within refugia. Estimates of PD show that diversity was highest in the Uluguru, Nguru and East Usambara Mountains and several lineages (from Mount Kenya, South Pare and the Uluguru Mountains) stand out as being evolutionarily distinct as a result of isolation in forest refugia. PD was lower than expected by chance, suggesting that the phylogenetic signal is influenced by an unusually low number of extant lineages with long branch lengths, which is probably due to the retention of palaeoendemic lineages. Main conclusions The biogeographic patterns associated with Kinyongia are the result of long evolutionary histories in isolation. The phylogeny is dominated by ancient lineages whose origins date back to the early Miocene/Oligocene as a result of continental wide forest fragmentation and contraction due to long term climatic changes in Africa. The maintenance of palaeoendemic lineages in refugia has contributed substantially to the remarkably high biodiversity of East Africa. [ABSTRACT FROM AUTHOR]

Reptiles have an amazing diversity of life-history attributes ranging from the shortest-to longest-lived of vertebrate species. Estimating survival in wild populations is of key importance when understanding population dynamics and life-history evolution. However, data are lacking for a large and charismatic group of lizards, the chameleons. We conducted a Robust Design (RD) capture-mark-recapture (CMR) experiment on the Cape dwarf chameleon, Bradypodion pumilum, at two nested sites within the Cape Town Metropolitan Area, South Africa, in order to estimate survival and movement of adults in and around an isolated 3.5 ha patch of suitable habitat. Over a nine-week period, 97 individuals were identified in 379 captures from five primary capture sessions with three secondary events each. Analysis of CMR data provided evidence that smaller chameleons have a substantially lower survival per 10-day period than larger chameleons. RD analysis showed that males were more prone to temporary emigration than females, while open multi-strata analysis revealed that smaller chameleons more readily moved between the sites than larger chameleons. Our findings offer first important insights into chameleon survival and life-history dynamics, which suggest a more vagile subadult population and the possibility of male biased dispersal. Our results have implications for managing the conservation of threatened chameleon populations in highly fragmented urban habitats. [ABSTRACT FROM AUTHOR]

Glucocorticoids act throughout life to regulate numerous physiological and behavioral processes. Their levels are therefore highly labile, reacting to varying conditions and stressors. Hence, measuring glucocorticoids (and other steroids) in wildlife is challenging, and devising methods that are unaffected by the stress of capture and handling should be explored. Here we use the tip of free-ranging chameleons’ claws that were cut to allow individual identification, and report a steroids extraction and quantification method. Claw steroids present an integrated level representing the period of claw growth. We found that we could measure corticosterone in small amounts of chameleon claw matrix using commercial EIA kits. Using this method, we learned that in wild male chameleons, claw corticosterone levels were associated with body size. We suggest that claw-testing can potentially provide an ideal matrix for wildlife biomonitoring. [ABSTRACT FROM AUTHOR]

We compare phylogenetic hypotheses for iguanian (chameleonids) and anguimorph lizard groups (varanoids, xenosauroids, anguids) which were generated from analyses of genital (hemipenial) morphology, with recent molecular phylogenetic approaches towards the same groups. Taxa with infraspecific communication by means of visible, sexually dimorphic epigamic characters usually have less diverse genital structures than taxa with less developed visible epigamic characters but with a more highly developed chemical intersexual communication. Generally, it turned out in the cases considered here, that phylogenetic hypotheses based on hemipenial characters coincide much better with molecular-genetic phylogenies than with earlier concepts based solely on external morphology. It seems that genital morphological characters are phylogenetically more informative – on both the species and the supraspecific level – than external morphological characters at least in these examples, because the former seem not to be affected by environmental selective pressures but seem to be only subject to sexual selection. Our data suggest that sexual selective pressure on genital structural diversity is higher the less sexually dimorphic, optical cues for infraspecific communication have evolved. They further suggest a correlation with the mating system (single versus multiple matings). [ABSTRACT FROM AUTHOR]

The article focuses on a study which investigated the effects of predicated climate change on the endemic South African dwarf chameleons, Bradypodion. To predict the suitable climatic habitat for most the chameleon species and for their phylogenetic clades, a niche-based modelling technique was employed. The Intergovernmental Panel on Climate Change (IPCC) climate change scenarios were also used in the study. All models showed responses to predicted climate change but the degree and extent of these responses were individualistic. Most of them responded with a contraction in predicated climatic suitability while some registered an expansion or a shift.

We describe a new species of anole of the Norops schiedei group from western Guatemala. A distinctive suite of characters distinguish it from the remaining species of the group (e.g., prenasal scales fused to circumnasal; most midventral scales weakly keeled; all scales in prefrontal depression strongly keeled; scales comprising supraorbital semicircles about same size as scales between semicircles; all keels on dorsal surface of head oriented nearly longitudinally; hemipenis large and bilobate). [ABSTRACT FROM AUTHOR]

Many reptiles lay eggs with flexible shells that can progressively lose water until lethal dehydration under dry soil conditions. The number of eggs that develop together may influence the water exchange in the nest. We hypothesise that egg aggregation could reduce water lost under dry conditions. We exposed aggregated and isolated eggs to severe hydric stress followed by a period of rehydration. Hydric stress caused a general loss of water in common chameleon eggs. Initial egg mass did not affect survival but eggs that had lost more water had higher mortality and produced smaller hatchlings. Mass loss was higher and even lethal for isolated Chamaeleo chameleon eggs. However, aggregated eggs lost less water and most survived this period. After hydric stress, all surviving eggs gained mass via water absorption, and aggregation negatively affected water uptake. Isolated eggs hatched at smaller sizes than aggregated eggs. Aggregation also favoured hatching synchrony. Large clutches may favour hatching success of terrestrial flexible-shelled eggs incubated under severe drought conditions. [ABSTRACT FROM AUTHOR]

Ontogenetic habitat shifts have been documented in numerous fish and amphibians and in some reptiles. Intraspecific competition together with differential predation, prey size, social interactions, size-related thermal requirements, and morphological constraints on movement are often implicated in this ontogenetic habitat separation. In the current study, we combined field observation with experiments in seminatural arenas to test various hypotheses regarding the ontogenetic habitat shift that we have documented in the common chameleon. Juveniles (mean, 1 g) occupied low grasses and the adults (mean, 35 g) were found on bushes and trees. Overlap in habitat use between these two age classes was minimal. Our field experiments showed that juveniles actively avoid the presence of adults by concealment or flight. Adults readily attacked and consumed juveniles, regardless of their own mass. These results suggest that the risk of cannibalism towards juveniles is an important selective force behind the ontogenetic habitat shift observed in the common chameleon and may be important in other species too. [ABSTRACT FROM AUTHOR]