Chalcides Ocellatus Research Articles

Redescription of two nematode parasites infecting Reptilia in Qena Governorate

During a helminthological examination of Tarentola annularis (Geoffroy, 1828) and Chalcides ocellatus (Forskal, 1775), 12 out of 60 Tarentola annularis were found to harbour a large number of Spauligodon aspiculus, 30 out of 106 Chalcides ocellatus were found to harbour Thelandros aegypti.

COCCIDIAN BLOOD INFECTIONS OF LIZARDS IN EGYPT

The infection rates of coccidian blood parasites in the common lizards (Gekkonidae: Ptyodactylus hasselquistii, Tarentola annularis, Hemidactylus turcicus; Scincidae: Chalcides ocellatus, Chalcides sepsoides, Mabuya quinquetaeniata; Varanidae: Varanus niloticus and Lacertidae: Acanthodactylus boskianus) in Qena (Egypt) were investigated; 67 lizards (42%) out of 161 lizards were infected. The infection rate was 49% among males and 37% among females. The highest infection rate was found in the Gekkonidae P. hasselquistii (100%) and T. annularis (74%). However, 17% of H. turcicus, were parasitized. Meanwhile, in the Scincidae C. ocellatus, C. sepsoides and M. quinquetaeniata the percentage of the infection was 23%, 17% and 14%, respectively. Only one V. niloticus (Varanidae) was infected. None of A. boskianus (Lacertidae) were parasitized. Seasonal variations of infection rates seem to occur in T. annularis, in which high rates were found in summer (100%) and winter (77.8%). All P. hasselquistii were infected with Karyolysus sp., and 56% contained a mixed infection with Plasmodium sp., resulting in parasitaemia up to 14%. About 30% of T. annularis infections were due to Lankesterella sp., the others were due to Haemogregarina sp., both together infecting up to 6%. Lankesterella species was found in 0.02% of H. turcicus. The parasitaemia in Scincidae were 75% in C. ocellatus and 0.02% in C. sepsoides. In M. quinquetaeniata, up to 12% of blood cells possessed Hepatozoon sp. and in V. niloticus up to 0.5% was infected with Haemogregarina sp.

On the life cycle and morphology of development stages of Paraspiralatus sakeri Gibbons et al., 2004 (Nematoda: Spiroidea, Spirocercidae), a heteroxenic stomach parasite of falcons

Pitted darkling beetles (Adesmia cancellata) were infected with nematode eggs found in the alimentary tract of a gyrfalcon (Falco rusticolus) naturally infected with Paraspiralatus sakeri. Third-stage larvae in numbers between 1 and 84 were removed from the beetles 5weeks postinfection and were used for morphological studies as well as to infect domestic chicken, yellow-bellied geckos (Hemidactylus flaviviridis) and fringe-toed lizards (Acanthodactylus schmidti). All experimental animals, necropsied 4-38weeks later, were positive for spirally coiled nematode larvae located under the skin and in the interstitium of skeletal muscles. Despite similarities in general morphology, larvae from beetles and reptiles and chicken differed strikingly in the total body length and body width. Differences in length of the muscular oesophagus and distances of cervical papillae, nerve ring and excretory pore from the anterior end were less distinct. Morphology of these larvae matched with larvae found in subcutaneous cysts in naturally infected houbara bustards (Chlamydotis macqueeni) from Pakistan and UAE as well as with those detected in the muscles of an ocellated skink (Chalcides ocellatus).

Swimming through the substrate: the neoichnology of Chalcides ocellatus and biogenic structures of sand-swimming vertebrates

Swimming through the substrate: the neoichnology of Chalcides ocellatus and biogenic structures of sand-swimming vertebrates

Food composition of Ocellated Skink, Chalcides ocellatus (Forskal, 1775) (Squamata: Scincidae), from the Cyprus Island

th December. Abstract. We examined the food composition of the museum specimens of Chalcides ocellatus (Forskal, 1775) col- lected from Morphou (= Guzelyurt) and Gonyeli (Nicosia District, Northern Cyprus). The stomach contents of 41 (23 males, 11 females, and 7 juveniles) individuals were analyzed, and totally 86 prey items were detected. The species was found to feed mainly on a variety of insects (94.3%) and particularly on coleopterans (62.1%). No statistical ly signifi- cant sex- or age-dependent difference was observed in the feeding regime. In conclusion, the diet of C.ocellatus was based mainly on insects and other arthropods.

Parasitological and Biochemical Studies on Chalcides ocellatus Inhabiting Damietta Region

Parasitological and Biochemical Studies on Chalcides ocellatus Inhabiting Damietta Region

Comparative study on the tongue of Bufo regularis and Chalcides ocellatus in relation to their habitats

The present study investigated the structure of the tongue of the toad, Bufo regularis and the lizard, Chalcides ocellatus. They have different feeding habits and live in different habitats. The tongue of the toad contains two types of lingual papillae; fungiform papillae and filiform papillae. The fungiform papillae are usually scattered among the filiform papillae and are believed to function in gustation and in the secretion of salivary fluid. Scanning electron microscopical studies revealed that no ciliated cells were observed on the surface of the filiform papillae or in the surrounding area of the sensory disc. In C. ocellatus the tip of the tongue is bifurcated and keratinized. The dorsal surface of the tongue is covered with several types of papillae; irregular, scale and ridge-shaped. Taste buds were present in the epithelium of the tongue. The lingual glands consist of mucous cells that form crypt-like invaginations between papillae. The present study revealed that there is a marked correlation between the structure of the tongue of both B. regularis and C. ocellatus and habitats and feeding mechanism of the two species.

Slow evolving satellite DNAs: the case of a centromeric satellite in Chalcides ocellatus (Forskål, 1775) (Reptilia, Scincidae)

Satellite DNAs represent a preponderant portion of eukaryotic genomes, and despite the ample literature on satDNAs of eukaryotes little is known about these repetitive elements in reptiles. Studies on reptiles satellite DNAs have been mainly focused on lacertid lizards and only one aimed at characterising these repetitive elements in skinks. Here, the isolation and characterisation of a satellite DNA in two populations of the ocellated skink, Chalcides ocellatus (Forskål, 1775), is presented. The repetitive element isolated is located at centromeres of all chromosomes of the complement, shows a tendency towards AT enrichment (53.5%), and contains short motifs that are common in centromeric satellites of eukaryotes (TG/CA, GAAA). The satellite shows an extremely low evolutionary rate (0.13% per million year) that make it unsuitable as a phylogenetic probe to assess the genetic differentiation of the populations investigated, that show a deep genetic divergence at mitochondrial level. The influence of satellite location on chromosomes and chromosomal morphology are invoked to explain this unusually slow mutation rate.

Ultrastructural Studies on the Tongue of Some Egyptian Lizards 1-Scincine Lizards Chalcides Oscellatus and Chalcides Sepsoides (Lacertilia, Scincidae)

Tongues of Egyptian lizards Chalcides ocellatus and Chalcides sepsoides are investigated under scanning and transmission electron microscope. Their tongues are divided into tip, anterior, middle and posterior regions. In C. ocellatus, the tip region is bifurcated and protected with strong, non-papillosed, keratinized epithelium. The lingual papillae are separating with wide trenches except in the middle region. Papillae of the anterior and posterior regions have serrated and imbricated ends oriented in the posterior direction. The surface epithelia is studded by tiny or reticular microvilli. Ultra-sections show that the imbricated portions have goblet cells rich in numerous secretory granules. The lamina propria of each papilla is provided with striated muscle fibers. The distribution and orientation of the lingual muscle fibers prove that the tongue is adapted for snipping, masticate and swallowing their praise. In C. sepsoides tongue, the tip region is slightly bifurcated. All lingual papillae have different shapes with narrow moats separating between them. Those of the anterior and posterior regions have free ends overlapped towards the anterior or posterior directions, respectively, while that of the middle region is not imbricated. The surface epithelia of the tongue has dispersed or aggregated microvilli. In the tongue of the C. sepsoides, new structures are described for the first time. At its ventral aspect, there is an accessory lingual muscle formed of numerous muscle fibers orient to the vertical, transverse or longitudinal directions. These orientations prove that the tongue is able to mash and suck the prey’s sherbets. At the end of the posterior region, there is a ciliated concave depression hosting a laryngotracheal organ, which has T-shaped crevice precedent by large fleshy highly ciliated lip supported by inflexible folds.

Diet ofChalcides ocellatus(Squamata: Scincidae) from Southern Egypt

ABSTRACT We studied the diet of Chalcides ocellatus (Forskal, 1775) from southern Egypt using stomach contents from a large series of specimens collected during the Yale University Prehistoric Expedition to Nubia. Only 2.5% of specimens contained identifiable prey items. Insect larvae, coleopterans and orthopterans were the most important prey items. The first two of these prey categories are typically among the most important in the diet of this species in other areas of its broad distribution. Males and females differed somewhat in their diets and had a dietary overlap of 0.607. Males had relatively larger head widths than females, but this is likely to be related to sexual selection rather than dietary segregation.

The phylogenetic position of Chalcides ocellatus (Squamata: Scincidae) from Yemen and Somalia

The skink Chalcides ocellatus (Forskal) is distributed around the Mediterranean region, Arabian Peninsula, and Horn of Africa. We examined C. ocellatus from Yemen and Somalia to clarify the biogeography of the species in the region of the Red Sea/Gulf of Aden. We examined 3612 bp of partial and complete mtDNA fragments (12S, 16S, ND1, cyt b, ND4, and adjacent tRNA) and 5380 bp of partial nuclear DNA fragments (BDNF, C-MOS, Rag1, PNN, and R35). Bayesian inference and Maximum-likelihood analysis placed the Somalia and Yemen specimens with those from the Eastern Mediterranean. We were unable to resolve a split between East African (Somalia) and Arabian (Yemen) populations with mtDNA, nuclear loci, and combined loci analyses.

Heavy metal pollution across sites affecting the intestinal helminth communities of the Egyptian lizard, Chalcides ocellatus (Forskal, 1775)

This study aimed to investigate the possible effects of heavy metal pollution across sites and some biological factors on helminth communities infecting the lizard, Chalcides ocellatus. The possibility of heavy metal accumulation by such helminths was also investigated. A total of 202 C. ocellatus were collected from three different sites (industrial, rural, and urban systems) in Ismailia governorate, Egypt, during summer 2009. The lizards were classified according to their sex and size and were examined for the intestinal helminths. Heavy metal levels were detected in the intestinal tissue of the lizards and the recovered helminths. Species richness was 6, 5, and 3 in rural, urban, and industrial systems, respectively. Significant site variations regarding infection prevalence, intensity, and abundance were encountered at different levels. Some noticeable effects of the host size were found. The significant differences found between the metal levels of the intestinal tissues and the recovered helminths and the other relations found in this study may be indications for a possible metals accumulation capacity by helminths. The cestode Oochoristica tuberculata could be a promising biomonitor for Cu and Pb, while the intestinal nematodes were less sensitive to the pollution. Differences in the accumulation capacity may be attributed to the intensity of infection, parasite species, and metal. The observed patterns of distribution and occurrence of helminths and the metals accumulation capacity reflect the need for more studies since this study proposes the model intestinal helminth/C. ocellatus as another promising bioindication system in the terrestrial habitat, especially in areas where the lizard C. ocellatus are available.

Uterine Gene Expression in the Live-Bearing Lizard, Chalcides ocellatus, Reveals Convergence of Squamate Reptile and Mammalian Pregnancy Mechanisms

Although the morphological and physiological changes involved in pregnancy in live-bearing reptiles are well studied, the genetic mechanisms that underlie these changes are not known. We used the viviparous African Ocellated Skink, Chalcides ocellatus, as a model to identify a near complete gene expression profile associated with pregnancy using RNA-Seq analyses of uterine transcriptomes. Pregnancy in C. ocellatus is associated with upregulation of uterine genes involved with metabolism, cell proliferation and death, and cellular transport. Moreover, there are clear parallels between the genetic processes associated with pregnancy in mammals and Chalcides in expression of genes related to tissue remodeling, angiogenesis, immune system regulation, and nutrient provisioning to the embryo. In particular, the pregnant uterine transcriptome is dominated by expression of proteolytic enzymes that we speculate are involved both with remodeling the chorioallantoic placenta and histotrophy in the omphaloplacenta. Elements of the maternal innate immune system are downregulated in the pregnant uterus, indicating a potential mechanism to avoid rejection of the embryo. We found a downregulation of major histocompatability complex loci and estrogen and progesterone receptors in the pregnant uterus. This pattern is similar to mammals but cannot be explained by the mammalian model. The latter finding provides evidence that pregnancy is controlled by different endocrinological mechanisms in mammals and reptiles. Finally, 88% of the identified genes are expressed in both the pregnant and the nonpregnant uterus, and thus, morphological and physiological changes associated with C. ocellatus pregnancy are likely a result of regulation of genes continually expressed in the uterus rather than the initiation of expression of unique genes.

Associations between reproductive cycle and occurrence of intestinal helminths infecting the Egyptian lizard, Chalcides ocellatus

Little attention has been given to the association between the host reproductive cycle and the dynamics of parasitic infection in the reptilian model. This relationship was investigated in this study with the common intestinal nematode, Thelandros schusteri (Family: pharyngodonidae) infecting the Egyptian lizards, Chalcides ocelattus. Fifty threelizards were collected during winter and spring 2009 and were weighted and sexed. The gonads were weighted and gonadosomatic index (GSI) was calculated; both represent measures of the reproductive cycle. The intestinal nematodes were recovered from the intestine by the standard technique. Results showed that the seasonal variation did not affect the infection prevalence in male or female lizards while GSI greatly affected the prevalence in female lizards only. Females with low GSI showed the highest infection prevalence while, those of high GSI showed the highest intensity of infection. Positive or negative correlations between number of follicles/ ovary, gonad mass or GSI and the intensity of infection in female hosts suggested that the investment in reproduction of females is more costly than for males. We interpret the high intensity of infection in females to be an effect of the reproductive cycle and conclude that sex dependent difference is very important in such pattern of host parasite relationship when aspects of reproductive cycle are considered and that the host reproductive investment may be a factor contributing to occurrence of parasitic infection.

Oochoristica chalcidesi n. sp. (Eucestoda: Linstowiidae) from the ocellated skink, Chalcides ocellatus (Forskal, 1775) in the United Arab Emirates

Five out of ten ocellated skinks (Chalcides ocellatus) examined in Dubai between 2007 and 2010 were infected with cestodes of the genus Oochoristica. Out of the 36 collected tapeworms seven specimens were used to describe a new species. Oochoristica chalcidesi n. sp. belongs to the group of species with 25 to 35 testes arranged in two clusters. The lobes of the ovary are subdivided into 4-5 lobules in a similar way as O. ubelakeri described from Agama atra in Namibia. Both species differ in the presence of a neck, a lower number of mature segments in O. chalcidesi n. sp. and a different position of the cirrus pouch in relation to the ovary, as well as in the distribution of uterine capsulae in gravid segments.

The Amphibians and Reptiles of the 1962–1965 Yale University Prehistoric Expedition to Nubia

The Yale University Prehistoric Expedition to Nubia collected zoological specimens and archeological artifacts from Egypt and the surrounding region from 1962 to 1965. A total of 2486 herpetological specimens were collected during this time, representing 51 species and 13 families. Among the herpetological specimens is a series of 1232 Chalcides ocellatus and a recently described species of spitting cobra (Naja nubiae). Because most of the collection sites are now under Lake Nasser, most specimens represent extirpated populations. Some specimens are of taxa now considered endangered species in Egypt. Although the primary purpose of the YUPEN expedition was to preserve the rich anthropological history south of Aswan, the herpetological specimens that were preserved provide a valuable temporal snapshot into the historical ecosystems that were present in Lower Egypt.

Phylogeography of the ocellated skink Chalcides ocellatus (Squamata, Scincidae), with the use of mtDNA sequences: A hitch-hiker’s guide to the Mediterranean

We analyze geographic genetic variation in C. ocellatus to evaluate the influences of major climatic, paleogeographic and anthropogenic factors in its biogeographic history. Ninety four specimens from 61 populations were collected across all of its geographical range and analyzed based on partial mitochondrial sequences (cyt b, 12S, and ND1). Our results demonstrate that an ancestral form of C. ocellatus, which expanded in northwestern Africa at the end of Miocene, diverged in at least three separate evolutionary lineages approximately 4.57Ma: C. humilis spread south of the Sahara, while the other two (C. ocellatus sensu stricto) were restricted in the coastal North African region. The complicated history of the ocellated skink is a result of multiple vicariant phenomena followed by multiple active or passive dispersals. The Messinian salinity crisis and the re-flooding of the Mediterranean basin, the climatic transition from Middle to Upper Pliocene, and the hyperarid phase of the Sahara, affected the distribution and diversification of C. ocellatus, while in historical times it was introduced in the central Mediterranean islands and eastern Mediterranean region from Tunisia and Cyrenaica, respectively.

Analysis of pellets from a suburban Common Kestrel Falco tinnunculus nest in El Harrach, Algiers, Algeria

The diet of a Common Kestrel Falco tinnunculus in a suburban area of Algiers at El Harrach was determined by pellet analysis over two years. In both years, the hybrid sparrow (Passer domesticus × P. hispaniolensis) was the main prey item, based on relative frequency (22.3% and 58.7% in 1999 and 2000, respectively). Greenfinch Carduelis chloris was the next most important prey item in 1999 (14% of relative frequency), followed by Kuhl's Pipistrelle Pipistrellus kuhli (9.4%), striped earwigs Labidura riparia and rose chafers Potosia cuprea (7.9% each) and millipedes Polydesmus sp., which contributed 5.8% of the relative proportion. In 2000, the other prey species in the diet made up less than 5% of the proportion. In terms of biomass, the hybrid sparrow was the main prey represented, with 47.6% in 1999 and 78.7% in 2000, followed by Carduelis chloris, with 29.8% of biomass, and ocellated skink Chalcides ocellatus, with 10.2% of biomass in 1999. In 2000, the other prey species made up less than 10% of the biomass. As with other urban studies in Europe, birds make up an important component of the kestrel's diet.

Morphology, niche segregation, and escape tactics in a sand dune lizard community

We examined patterns of co-existence for three species of scincid lizards ( Sphenops sepsoides, Scincus scincus, and Chalcides ocellatus) in the simple sand dune habitat of North Sinai, Egypt. We first examined the morphological differences among the three species and compared their niche use and escape tactics in the context of their morphologies. Our results suggests that natural selection has favored two different phenotypes, Scincus scincus's long limbs with toe fringes and Sphenops sepspoides's extremely reduced limbs for sand locomotion. These two sand specialists, Sphenops sepsoides and Scincus scincus, shared microhabitats such as soft substrate and occurred further away from vegetation but showed strong separation in the surface temperatures at which they were active. The generalist species, C. ocellatus which lacked toe fringes and had relatively short limbs that were not reduced enough for fossorial movement, was found closer to vegetation and on harder substrates where such traits may be beneficial. Escape tactics may further strengthen habitat partitioning between desert generalists and sand specialists as C. ocellatus sprint to vegetation to escape predators whereas both sand specialists dive into the sand. Our results suggest that traditional ideas about predation risk may not apply to sand diving lizards as they may be able to venture far from vegetation refuges without increased vulnerability to predation.

Factors affecting helminths community structure of the Egyptian lizardChalcides ocellatus(Forskal, 1775)

The variation in the component community structure of intestinal helminths in the lizard Chalcides ocellatus (Forskal, 1775) was studied in relation to the seasonal variation and host weight and sex. 120 lizards were collected seasonally during year 2004, from Al Firdan, Ismailia governorate, Egypt. The helminths community consisted of six species (five nematodes and one cestode). The various helminths differed according to host sex. The prevalence of total helminths infection was 67.6 % while the prevalences of Thelandros schusteri, Pharyngodon mamillatus, Parapharyngodon bulbosus, Cosmocerca vrcibradici, Spauligodon petersi and Oochoristica maccoyi were 43.4%, 3.9 %, 13.2%, 5.3%, 6.6%, and 14.3%, respectively. The results showed that the season was the main factor affecting infracommunity species richness and parasite abundance. Moreover, there was interaction between season and host sex on abundance of P. bulbosus. The prevalence of intestinal helminths varied significantly in relation to host weight classes and sex in some species. Helminths abundance and intensity were independent from host sex. In addition, correlations were found between total helminths abundance and host weight. In conclusion, the helminths community of C. ocellatus was depauperate and the influence of the studied factors varied from species to another one. We cannot say if the low species richness and infection rates observed in the present study are typical of the host species or if they are due to characteristics of the study area, since no available data on parasite assemblages exist for other C. ocellatus populations.