Ptyodactylus Guttatus Research Articles

Ecophysiological trait variation in desert versus Mediterranean populations of a gecko

AbstractPopulations inhabiting several biomes may experience different abiotic and biotic conditions, exerting local selection pressures. Temperature and water regimes are interconnected variables, that may differ between biomes, and greatly influence ecophysiological traits, such as metabolic and evaporative water loss rates. We hypothesized that Ptyodactylus guttatus (Sinai Fan‐fingered Gecko) individuals, which occupy the Mediterranean and desert biomes across Israel, would follow the “metabolic cold adaptation” hypothesis and be adapted to the microclimate in the biome they inhabit. We thus predicted that desert individuals would prefer lower temperatures, and have lower resting metabolic rates and evaporative water loss rates at higher ambient temperatures than Mediterranean individuals. We also predicted that Mediterranean individuals would have a better body condition than individuals from the desert, because of higher primary productivity in the Mediterranean biome, and would therefore have higher mite loads. We further predicted that geckos from the desert would have longer limbs, enabling them to lose more heat to the environment, according to Allen's rule. To test these hypotheses, we measured the temperature preferences, field body temperatures, resting metabolic rates, evaporative water loss rates, body conditions, mite loads, and limb lengths of 82 P. guttatus individuals collected from four localities two from the desert biome and two from the Mediterranean biome. There were no significant differences in any of the tested traits when comparing between biomes. However, we found some differences in the evaporative water loss rates, body temperatures, body condition, and forelimb lengths between the northernmost and southernmost, and driest and wettest localities, supporting some of our predictions. Our results highlight the importance of the resolution of the analysis. Although some ecophysiological traits of P. guttatus seem to be conserved across localities and biomes, thermal plasticity in these traits may have helped this species reach its current distribution and occupy two biomes.

Two new mite species of the genus Geckobia Mégnin (Acariformes: Pterygosomatidae) from Israel

Two new species of pterygosomatid mites parasitizing Sinai fan-fingered gecko Ptyodactylus guttatus Heyden (Phyllodactylidae) from Israel are described: Geckobia bochkovi sp. nov. and Geckobia synthesys sp. nov. The former species is the most similar to Geckobia squameum Bertrand, Paperna, and Finkelman, 1999, but differs by the presence of a well-outlined, slightly concave propodonotal shield in its anterior and posterior margin, fine-pointed dorsal setae that slightly increase in length from the anterior to the posterior part of the idiosoma, leg setae l'FI and l'GI, shape of coxal setae 4a, 4b and 4c which are slender and smooth or with barely discernible serration. The latter species is most similar to Geckobia keegani Lawrence, 1953 but differs in the shape of the propodonotal shield, which is almost straight in its posterior margin, the presence of five pairs of setae on the shield, 19-28 pairs of idiosomal ventral setae, three genital setae and leg setae l'GI, l'GIV, vFI-II, vFIII-IV, lFIII-IV and vTrIV.

Conserved ecophysiology despite disparate microclimatic conditions in a gecko.

Microscale differences in the habitats organisms occupy can influence selection regimes and promote intraspecific variation of traits. Temperature-dependent traits can be locally adapted to climatic conditions or be highly conserved and insensitive to directional selection under all but the most extreme regimes, and thus be similar across populations. The opposing slopes of Nahal Oren canyon in the Carmel Mountains, Israel, are strikingly different: the south-facing slope receives intensive solar radiation, is hot and supports mostly annual vegetation, whereas the north-facing slope is ~10°C cooler, more humid, and supports Mediterranean woodland. We examined whether these differences manifest in the thermal physiology of a common gecko species Ptyodactylus guttatus in controlled laboratory conditions. We predicted that geckos from the hotter south-facing slope would prefer higher temperatures, have faster gut passage times, lower metabolic and evaporative water loss rates, and start diel activity earlier compared with north-facing slope conspecifics. Contrary to these predictions, there were no differences between any of the ecophysiological traits in geckos from the opposing slopes. Nevertheless, our data showed that individuals from the north-facing slope were generally more active in earlier hours of the afternoon compared with south-facing individuals. We suggest that P. guttatus individuals disperse between the slopes and either gene-flow or behavioral plasticity deter local adaptation, resulting in similar physiological traits. Perhaps a stronger contrast in climatic conditions and a stronger barrier are needed to result in interpopulation divergence in temperature-dependent traits.

Ultrastructural comparison between the tongue of two reptilian species endemic in Egyptian fauna; Bosc's fringe-toed lizard Acanthodactylus boskianus and Sinai fan-fingered gecko Ptyodactylus guttatus.

The current observations focused on the ultrastructure comparison between the tongue of two reptile species endemic the Egyptian fauna; Bosc's fringe-toed lizard Acanthodactylus boskianus and Sinai fan-fingered gecko Ptyodactylus guttatus to exhibit the relationship between the lingual epithelium and its function according to their specific feeding strategy. A. boskianus possessed triangular elongated tongue with bifurcated tapering apex and wide base while; the P. guttatus had a triangular flattened tongue with conical shallow bifurcated apex and broad base. The ventral surface of the lingual apex of A. boskianus had transverse while in P. guttatus had two oval pads and median ventral groove. Both surfaces of the tongue of both examined species are covered by stratified squamous epithelium with great variability of degree of keratinization. The dorsal epithelium formed flattened and conical filiform papillae in A. boskianus, while in P. guttatus formed cylindrical papillae, conical, and tall filiform ones. Few taste buds are observed on the fore-tongue but increase on the mid-tongue of A. boskianus, while in P. guttatus, numerous taste buds are distributed on the fore-tongue and mid-tongue. Both surfaces of the laryngeal mound of both examined species provided with numerous of cilia and orifices of laryngeal gland. The present results confirmed that the tongue of A. boskianus acts as a chemoreceptor organ to follow pheromone trails of prey and mates. While in P. guttatus the tongue may play an important role in the feeding mechanism and act as a chemoreceptor organ.

Measuring body condition of lizards: a comparison between non-invasive dual-energy X-ray absorptiometry, chemical fat extraction and calculated indices

BackgroundCondition indices (CIs) are used in ecological studies as a way of measuring an individual animal’s health and fitness. Noninvasive CIs are estimations of a relative score of fat content or rely on a ratio of body mass compared to some measure of size, usually a linear dimension such as tarsus or snout-vent length. CIs are generally validated invasively by lethal fat extraction as in a seasonal sample of individuals in a population. Many alternatives to lethal fat extraction are costly or time consuming. As an alternative, dual-energy X-ray absorptiometry (DXA) allows for non-destructive analysis of body composition and enables multiple measurements during an animal’s life time. DXA has never been used for ecological studies in a small, free-ranging lizard before, therefore we calibrated this method against a chemical extraction of fat from a sample of 6 geckos (Israeli fan toed gecko Ptyodactylus guttatus) ranging in body mass between 4.2–11.5 g. We then used this calibrated DXA measurements to determine the best linear measurement calculated CI for this species. ResultsWe found that fat mass measured with DXA was significantly correlated with the mass of chemically extracted fat for specimens more than 4.8 g (N = 5, R2 = 0.995, P < 0.001). Fat percentage regressed with body mass significantly predicted the DXA fat percentage (N = 29, R2adj. = 0.862, p < 0.001). Live wet mass was significantly correlated with predicted fat mass (N = 30, R2 = 0.984, P < 0.001) for specimens more than 4.8 g. Among the five calculated non-invasive CIs that we tested, the best was mass/SVL.ConclusionsWe recommend that in situations where DXA cannot be used, that the most accurate of the body condition estimators for this species is mass/SVL (snout-vent length) for both sexes.

Asymmetric Behavior in Ptyodactylus guttatus: Can a Digit Ratio Reflect Brain Laterality?

The digit ratio, an indicator of brain laterality, is the ratio of the second and fourth digits on the left (L24) or right foot (R24). Much of the research on the digit ratio and brain laterality focuses on primates, rather than other species such as reptiles. We tested whether the digit ratio in the gecko Ptyodactylus guttatus was associated with behaviors attributed to brain laterality. We examined risk-taking behavior (time spent under cover), foot preference (which foot was the first to start moving) and the side from which geckos bypassed an obstacle, in relation to the digit ratio. Geckos with longer fourth digits on their left hind foot (higher digit ratio) spent more time under cover. Geckos starting to move with their left leg were much more likely to bypass obstacles from the right side, and vice versa. This is the first evidence of laterality being associated with the digit ratio in reptiles. Comparisons among vertebrates are needed in order to decipher the evolutionary origin of the commonalities and peculiarities of brain asymmetry and disentangle the patterns and drivers of our evolutionary tree.

Comparative and functional study of integumentary system of two different reptiles: adaptation to their different modes of life

Aim of the work: the present study aimed to illustrate the structure and function of the integumentary system of two reptile''s species (Bosc’s fringe toed-lizard (Acanthodactylus boskianus, A. boskianus)and spotted fan-fingered gecko (Ptyodactylus guttatus , P. guttatus) and discussed the influence of different behaviors on their structure (keratinzation and pigmentation, claws, adhesion pads and sensory hairlets). Material and methods: the present study used light and scanning electron microscopy to investigate the structure of skin layers of A. boskianus and P. guttatus. Results: the thin epidermal layer of Acanthodactylus boskianus was covered by hard keratinized horny epidermal scales, while the epidermal layer of Ptyodactylus guttatus was well distinguished and covered by soft keratinized layer. Moreover, in P. guttatus the scales were non-overlapping along the whole length of the body with dome-like shaped on head region, while in A. boskianus the scales were overlapping and articulating with each other by thin hinge. In the present study the dermis of A. boskianus, was the deeper layer of collagenous connective tissue with a rich supply of blood vessels and nerves, while, the dermis of P. guttatus was formed of both collagenous and adipose tissues. Three types of chromatophores (melanophores, iridophores and xanthophores) were distinguished in the skin of both studied species. In A. boskianus, the melanophores were black, large and have dendrites invaginates in the stratum basale of epidermis. The iridophores (reflecting pigments) were scattered in the dermis with large number in the ventral skin than the dorsal one. In P. guttatus, melanphores they were larger, blackish brown and scattered within dermis beneath the iridophores with less number in P. guttatus than that of A. boskianus. Xanthophores (absorbing pigment) were more prominent in P. guttatus than that of A. boskianus. Conclusion: examination of the skin of the two studied reptile species revealed great variations in distributionof chromatophoresthrough the whole bodyreflecting the adaptation of each animal to different modes of life.

Comparative and functional study of integumentary system of two different reptiles: adaptation to their different modes of life

Aim of the work: the present study aimed to illustrate the structure and function of the integumentary system of two reptile''s species (Bosc’s fringe toed-lizard (Acanthodactylus boskianus, A. boskianus)and spotted fan-fingered gecko (Ptyodactylus guttatus , P. guttatus) and discussed the influence of different behaviors on their structure (keratinzation and pigmentation, claws, adhesion pads and sensory hairlets). Material and methods: the present study used light and scanning electron microscopy to investigate the structure of skin layers of A. boskianus and P. guttatus. Results: the thin epidermal layer of Acanthodactylus boskianus was covered by hard keratinized horny epidermal scales, while the epidermal layer of Ptyodactylus guttatus was well distinguished and covered by soft keratinized layer. Moreover, in P. guttatus the scales were non-overlapping along the whole length of the body with dome-like shaped on head region, while in A. boskianus the scales were overlapping and articulating with each other by thin hinge. In the present study the dermis of A. boskianus, was the deeper layer of collagenous connective tissue with a rich supply of blood vessels and nerves, while, the dermis of P. guttatus was formed of both collagenous and adipose tissues. Three types of chromatophores (melanophores, iridophores and xanthophores) were distinguished in the skin of both studied species. In A. boskianus, the melanophores were black, large and have dendrites invaginates in the stratum basale of epidermis. The iridophores (reflecting pigments) were scattered in the dermis with large number in the ventral skin than the dorsal one. In P. guttatus, melanphores they were larger, blackish brown and scattered within dermis beneath the iridophores with less number in P. guttatus than that of A. boskianus. Xanthophores (absorbing pigment) were more prominent in P. guttatus than that of A. boskianus. Conclusion: examination of the skin of the two studied reptile species revealed great variations in distributionof chromatophoresthrough the whole bodyreflecting the adaptation of each animal to different modes of life.

Comparative Functional Analysis of the Anatomy of the appendicular skeleton in two reptilian species

Aim of the work: the present study aimed to illustrate the osteological characters of the appendicular skeleton of two Egyptian lizard species, Acanthodactylus boskianus and Ptyodactylus guttatus and clarify the relationship between characteristics of the appendicular skeleton and mode of their locomotion of the two species. A. boskianus is diurnal insectivorous lizard forage in open area and it is a generalized ground-dwelling species and P. guttatus is a diurno-nocturnal omnivorous gecko which is a highly specialized climbing on vertical substrates. Material and methods: in the present study we used Alizarin red and Alcian blue as double skeletal staining to investigate the the bony and cartilaginous pattern of limbs and girdles of A. boskianus and P. guttatus. Results: in P. guttatus, the pectoral girdle was characterized by the presence of the interclavicles was dagger in shape and partially fused with clavicles, while it was cruciform and completely fused with the clavicles in A. boskianus. In P. guttatus, the epicoraoid was well developed, broad bony plates and fused with the interclavicles, while in A. boskianus it was narrow cartilaginous, plates and overlap in the mid-line. Moreover, in P. gutattus two fenestrae were appeared within coracoid and scapula with un-fenestrated cartilaginous sternum, while one fenestra appeared in both coracoid and sternum of A. boskianus. On other hand, the pelvic girdle of P. guttatus had complete fusions between the pubis, ischium and ilium, while in A. boskianus the pubis articulated poster-omedially with the ischium. In both P. gutattus and A. boskianus, the forelimbs posture was in horizontal plane, while the hind limbs were in vertical plane. In P. gutattus both the fore and hind limbs were relatively equal in length, while the fore limb in A. boskianus was greatly shorter than the hind limb. Conclusion: the P. gutattus is considered as a one of climbers species which have stout appendicular skeleton to support the climbing process on the vertical surface with relatively short limbs, while A. Boskianus is ground-dwellers and also good climbers and use their claws to walk and climbing on rocky areas and these abilities of locomotion depend on the flexibility of skeletal elements of its appendicular skeleton.

Comparative Functional Analysis of the Anatomy of the appendicular skeleton in two reptilian species

Aim of the work: the present study aimed to illustrate the osteological characters of the appendicular skeleton of two Egyptian lizard species, Acanthodactylus boskianus and Ptyodactylus guttatus and clarify the relationship between characteristics of the appendicular skeleton and mode of their locomotion of the two species. A. boskianus is diurnal insectivorous lizard forage in open area and it is a generalized ground-dwelling species and P. guttatus is a diurno-nocturnal omnivorous gecko which is a highly specialized climbing on vertical substrates. Material and methods: in the present study we used Alizarin red and Alcian blue as double skeletal staining to investigate the the bony and cartilaginous pattern of limbs and girdles of A. boskianus and P. guttatus. Results: in P. guttatus, the pectoral girdle was characterized by the presence of the interclavicles was dagger in shape and partially fused with clavicles, while it was cruciform and completely fused with the clavicles in A. boskianus. In P. guttatus, the epicoraoid was well developed, broad bony plates and fused with the interclavicles, while in A. boskianus it was narrow cartilaginous, plates and overlap in the mid-line. Moreover, in P. gutattus two fenestrae were appeared within coracoid and scapula with un-fenestrated cartilaginous sternum, while one fenestra appeared in both coracoid and sternum of A. boskianus. On other hand, the pelvic girdle of P. guttatus had complete fusions between the pubis, ischium and ilium, while in A. boskianus the pubis articulated poster-omedially with the ischium. In both P. gutattus and A. boskianus, the forelimbs posture was in horizontal plane, while the hind limbs were in vertical plane. In P. gutattus both the fore and hind limbs were relatively equal in length, while the fore limb in A. boskianus was greatly shorter than the hind limb. Conclusion: the P. gutattus is considered as a one of climbers species which have stout appendicular skeleton to support the climbing process on the vertical surface with relatively short limbs, while A. Boskianus is ground-dwellers and also good climbers and use their claws to walk and climbing on rocky areas and these abilities of locomotion depend on the flexibility of skeletal elements of its appendicular skeleton.

Foot-preference underlies bite-scar asymmetry in the gecko Ptyodactylus guttatus

ABSTRACTScar-asymmetry may reflect brain laterality because scar location may reflect behaviour when being attacked. This has been studied in a few organisms, but never in lizards. Wild geckos (Ptyodactylus guttatus) from Israel were examined for bite-scar numbers and their lateral asymmetry. Social status was documented in the field before capture. Foot-preference, for either the right (R-footed) or left (L-footed) hind leg was determined in six trials for each gecko on adults captured in Jerusalem. I studied 48 geckos: 15 R-footed, 6 ambidextrous and 9 L-footed females; 6 R-footed, 3 ambidextrous and 9 L-footed males. Adults showed significantly more bite-scars than juveniles. The proportion of L-footed males mirrored that of R-footed females.Ambidextrous and L-footed geckos had a higher social status. In males, R-footed individuals had more bite-scars on the right side of the body, while L-footed individuals had more on the left side. R-footed females had more bite-scars on the right side, while L-footed females had bite-scars equally on both sides. Bite-scar asymmetry correlated with hind-leg preference, clearly reflecting brain laterality. Since all ambidextrous males had high social status, that may be the driving factor behind the females’ different bite-scar pattern.

THE CALL OF THE SRI LANKAN GOLDEN GECKO CALODACTYLODES ILLINGWORTHORUM, ECOLOGICAL PARALLEL OF THE FAN-TOED GECKOS, GENUS PTYODACTYLUS (REPTILIA: SAURIA: GEKKONIDAE)

ABSTRACT Based on nine calls of Calodactylodes illingworthorum recorded in the wild in Sri Lanka, the ‘spontaneous’ call of the species is a very rapid series of 4–7 roughly similar chirps. Call parameters are compared to those of Ptyodactylus guttatus of Israel because the species are similar in morphology (size, proportions, digit shape, scutellation, coloration), ecology (rupicolous, nocturnal), and reproductive biology (clutches of two eggs, stuck to rock, in ‘rookeries’). The calls of the two species, despite similarity in basic structure, greatly differ in the number of chirps, chirp repetition rate, total duration, dominant frequency, and relative intensity level. The functional implications of these differences are briefly considered.

Sexual Dimorphism and Ecology of The Gecko, Ptyodactylus Guttatus

Geckos are generally nocturnal and show no sexual dichromatism, and males are usually smaller than females. Ptyodactylus guttatus is an unusual gecko. It is active by day and night and is sexually dichromatic, and males are larger than females. We studied P. guttatus at two sites in southern Israel. Eggs were laid between May and October at Haluqim, where we studied eggs in natural caves. At a second site, Hazeva, P. guttatus occur on buildings at a density of 390 ha−1. This is 195 times the density that the species occurs in natural habitats. At Hazeva, adult males inhabited large home ranges, which generally overlapped with one or more smaller home ranges of females. The pattern of home-range overlap presumably reflects the opportunities for mating. A path analysis was consistent with the hypothesis that females spaced themselves to gain access to insects (which they eat) attracted to wall lights on the buildings, and that males space themselves to gain access to female mates. We did not find evidence of territoriality in this population but observed males guarding females. Large male body size may provide priority access to mates, and the distinct male dorsal pattern may have arisen because light does not constrain the use of visual signals in these unusual, largely diurnal geckos, to the same extent as it may in nocturnal geckos.

Predatory behaviour of gekkonid lizards, Ptyodactylus spp., towards the scorpion Leiurus quinquestriatus hebraeus, and their tolerance of its venom

In the present pilot study the effect of the venom of the Israeli yellow scorpion (Leiurus quinquestriatus hebraeus (Birula, 1908)) on two Israeli fan-toed gecko lizards (Ptyodactylus guttatus von Heyden, 1827 and P. puiseuxi Boutan, 1893) was examined through (1) observations on feeding behaviour and (2) toxicity assays. It was shown that (1) the geckos ate the extremely venomous yellow scorpions in a sting-avoiding fashion and when occasionally stung they were not affected; (2) subcutaneous injections of lyophilized venom were survived by the scorpion-sympatric P. guttatus in doses of 1 mg of crude lyophilized venom per g of body weight (4000 times its ld 50 value for mice), in contrast with the presumably allopatric P. puiseuxi which died within 80 and 210 min from doses of 1 and 0.5 mg per g, respectively. The pharmacological and ecochemical aspects of the above tolerance are discussed.

Sarcocystis stenodactylicolubris n. sp., a new sarcosporidian coccidium with a snake-gecko heteroxenous life cycle.

Oocysts/sporocysts of Sarcocystis sp. measuring 9.7 (9-10) x 7.6 (7-8) microns were found in the intestinal contents of the Dahl's whip snake Coluber najadum. Of wide spectrum of experimentally inoculated hosts, only species of the family Gekkonidae--Ptyodactylus guttatus and Stenodactylus grandiceps--were found to be susceptible intermediate hosts. Transparent, barely visible sarcocysts found in tail, limbs and tongue striated muscles of the geckoes were 175-200 microns x 35-50 microns in size at 78 DPI. Ultrastructurally, the primary cyst wall was characteristic by spine-like villar protrusions up to 800 nm long, 200-250 nm in diameter at their base, tapering to thinner apex. Protrusions appear typically lobular or irregular in the cross-sections. Back-transmission from P. guttatus to Coluber rogersi leaded to oocysts/sporocysts excretion since 38 days post infection. Based on sarcocyst morphology and experimental data, Sarcocystis stenodactylicolubris is apparently a new species. Based on obtained and already published results, Sarcosporidia parasitising colubrid snakes as definitive hosts are suggested to be family specific on the level of their intermediate host.

Temperature selection and thermoregulation in the Moorish gecko, Tarentola mauritanica

Abstract Temperature selection in a thermal gradient and the physiological responses to heat exposure were studied in the Moorish gecko, Tarentola mauritanica, from Crete. In association with previous indications that the Moorish gecko has a bimodal activity pattern, we found a bimodal temperature selection with modes at 27-28 and 30-32°C. In this respect, it resembles the closely related Israeli gecko, Ptyodactylus guttatus. However, Tarentola is more susceptible to heat exposure and has a moderate thermoregulatory capacity compared to P. guttatus and this is probably related to its reaching more northern latitudes than Ptyodactylus. During heat exposure (up to 40°C) oxygen consumption increased significantly and was not sustained by the moderate increase (Q10 = 1.44) in heart frequency. We found a significantly lower heating rate than cooling rate in Tarentola. This is in accord with allometric predictions for its low body mass and might stem from the high mass-specific evaporative water loss and from the relatively small increment in heart rate during heat exposure which may adaptively retard heat gain from the environment and maximize its activity periods.

Development of the subdigital adhesive pads of Ptyodactylus guttatus (Reptilia: Gekkonidae).

Subdigital adhesive pads play an important role in the locomotion of many species of gekkonid lizards. These pads consist of integrated components derived from the epidermis, dermis, vascular system, subcuticular tendons, and phalanges. These components become intimately associated with each other during the developmental differentiation of the digits and the sequence of this integration is outlined herein in Ptyodactylus guttatus. The pads initially appear as paired swellings at the distal tips of the digits. Subsequently, a fan-like array of naked scansors develops on the ventral surface of each digit, at about the same time that scales differentiate over the surface of the foot as a whole. At the time of appearance of the naked scansors, the vascular sinus system of the pad also differentiates, along with subcuticular connective tissue specializations. At this stage the digits, along with the rest of the body, are clad in an embryonic periderm. Only after hatching and as the periderm is shed, do the epidermal setae and spines appear. The developmental sequence described here is consistent with predictions previously advanced about the evolutionary origin and elaboration of subdigital pads in gekkonid lizards. The paucity of available staged embryonic material leaves many questions unresolved.