Eublepharis Macularius Research Articles

The Effect of Enrichment on Leopard Geckos (Eublepharis macularius) Housed in Two Different Maintenance Systems (Rack System vs. Terrarium).

The aim of this study was to test the usefulness of environmental enrichment for Eublepharis macularius depending on the maintenance method (terrarium vs. rack system). The hypothesis was that reptiles kept in an extremely low-stimulus environment (rack system) would be more prone to interact with environmental enrichment items than those kept in a biotope terrarium. During the study, 21 female geckos were kept in two types of captive enclosures: 9 in terrariums, and 12 in rack system boxes in groups of 3 animals per enclosure. During the enrichment sessions, geckos were observed for 45 min while enrichment items (dry and wet hides, a new feeding method, a new object) were present in the enclosure. All geckos showed interest in enrichment items that enabled hiding and climbing. Animals kept in the rack system showed significantly lower latency in approaching enrichment items and a higher frequency of enrichment interactions than lizards in biotope terrariums. However, no significant differences were found in the total time spent interacting with enrichment items between geckos in the two settings.

The revised reference genome of the leopard gecko (Eublepharis macularius) provides insight into the considerations of genome phasing and assembly.

Genomic resources across squamate reptiles (lizards and snakes) have lagged behind other vertebrate systems and high-quality reference genomes remain scarce. Of the 23 chromosome-scale reference genomes across the order, only 12 of the ~60 squamate families are represented. Within geckos (infraorder Gekkota), a species-rich clade of lizards, chromosome-level genomes are exceptionally sparse representing only two of the seven extant families. Using the latest advances in genome sequencing and assembly methods, we generated one of the highest-quality squamate genomes to date for the leopard gecko, Eublepharis macularius (Eublepharidae). We compared this assembly to the previous, short-read only, E. macularius reference genome published in 2016 and examined potential factors within the assembly influencing contiguity of genome assemblies using PacBio HiFi data. Briefly, the read N50 of the PacBio HiFi reads generated for this study was equal to the contig N50 of the previous E. macularius reference genome at 20.4 kilobases. The HiFi reads were assembled into a total of 132 contigs, which was further scaffolded using HiC data into 75 total sequences representing all 19 chromosomes. We identified 9 of the 19 chromosomal scaffolds were assembled as a near-single contig, whereas the other 10 chromosomes were each scaffolded together from multiple contigs. We qualitatively identified that the percent repeat content within a chromosome broadly affects its assembly contiguity prior to scaffolding. This genome assembly signifies a new age for squamate genomics where high-quality reference genomes rivaling some of the best vertebrate genome assemblies can be generated for a fraction of previous cost estimates. This new E. macularius reference assembly is available on NCBI at JAOPLA010000000.

Record of Cryptosporidium serpentis from Goniurosaurus kuroiwae sengokui (Reptilia, Squamata, Eublepharidae) in Tokashikijima, Okinawa Prefecture, Japan.

In reptiles, infection with Cryptosporidium parasite can be lethal, especially in species of family Eublepharidae such as Eublepharis macularius and Goniurosaurus splendes species. We investigated the presence of Cryptosporidium spp. in wild reptiles, especially Goniurosaurus spp., in five islands of Japan. Nested PCR was performed to detect Cryptosporidium spp. in 38 fecal samples of 9 reptile species from five islands of Japan, and 3 (3/8) positive samples of Goniurosaurus kuroiwae sengokui from Tokashikijima, Okinawa Prefecture were detected. A BLAST search of the detected gene sequences revealed that the all 3 samples were identified as Cryptosporidium serpentis, a reptile-specific Cryptosporidium parasite. This is the first record of Cryptosporidium from a wild Goniurosaurus species in Japan and worldwide.

Description and assessment of the Enigma syndrome (ES) in leopard geckos (Eublepharis macularius) with regard to its relevance as trait of breeding heritable defects

Description and assessment of the Enigma syndrome (ES) in leopard geckos (Eublepharis macularius) with regard to its relevance as trait of breeding heritable defects

Temperature Incubation Influences Gonadal Gene Expression during Leopard Gecko Development.

During development, sexual differentiation results in physiological, anatomical and metabolic differences that implicate not only the gonads but also other body structures. Sex in Leopard geckos is determined by egg incubation temperature. Based on the premise that the developmental decision of gender does not depend on a single gene, we performed an analysis on E. macularius to gain insights into the genes that may be involved in gonads' sexual differentiation during the thermosensitive period. All the genes were identified as differentially expressed at stage 30 during the labile phase of sex differentiation. In this way, the expression of genes known to be involved in gonadal sexual differentiation, such as WNT4, SOX9, DMRT1, Erα, Erβ, GnRH, P450 aromatase, PRLand PRL-R, was investigated. Other genes putatively involved in sex differentiation were sought by differential display. Our findings indicate that embryo exposure to a sex-determining temperature induces differential expression of several genes that are involved not only in gonadal differentiation, but also in several biological pathways (ALDOC, FREM1, BBIP1, CA5A, NADH5, L1 non-LTR retrotransposons, PKM). Our data perfectly fit within the new studies conducted in developmental biology, which indicate that in the developing embryo, in addition to gonadal differentiation, sex-specific tissue and metabolic polarization take place in all organisms.

Molecular evidence of Monocercomonas and Acanthamoeba in the feces of captive reptiles

Reptiles are frequently kept as pet animals. They are considered as important reservoirs of protozoa with veterinary-medical significance. At a reptile farm in Ireland, fecal samples were collected from 98 captive reptiles, representing 43 species of three orders (Squamata, Testudines, and Crocodylia). After DNA extraction, all samples were screened by conventional PCRs, targeting the ribosomal small subunit (SSU) RNA and alpha-tubulin genes of trichomonads and SSU RNA gene of Acanthamoeba spp. One leopard gecko (Eublepharis macularius) was positive for a not yet reported species/genotype of the genus Monocercomonas, different from M. colubrorum. Various Acanthamoeba genotypes were detected in six reptilian species, i.e., Acanthamoeba genotype T11 in Eunectes notaeus and Heloderma suspectum/horridum; genotype T4 in Varanus exanthematicus, Chlamydosaurus kingii, and Macrochelys temminckii; and the genotype T13 in Iguana iguana. Some of these amoeba species might have clinicopathological significance in both humans and animals. Our findings highlight the importance to monitor pathogenic protozoa in pet as well as wildlife reptiles, as a source of possible infection for animals and humans living nearby.

Response to the future climate change effect of two leopard geckos’ distribution (Sauria: Eublepharidae) in Iran

This study investigates the climate change effects on the distribution range of two species of nocturnal lizards in Iran. Using climate change scenarios recently (2021) published by IPCC, two species of leopard geckos that are distributed in the northeast ( Eublepharis turcmenicus ) and southwest ( Eublepharis angramainyu ) of Iran were selected and analyzed because they are only members of the family Eublepharidae in Iran and under high risk of extinction in the wild. We found that the most important bioclimatic variables that could affect the presence of these species are the minimum temperature in the coldest month of the year and the mean temperature in the wettest season; the Mean Temperature of the Driest Quarter and the Mean Temperature of the Coldest Quarter are the most important variables in future (2070) for E. angramainyu and E. turcmenicus , respectively. These variables are important directly at the beginning and end of the hibernation period of ectotherms such as lizards and can disrupt their life cycle by changing this period. Temperature changes over the next 50 years may not be a significant threat to these two species, as their range will be much wider than the current time, indicating that these species will be able to adapt to new conditions.

Spontaneous neuronal regeneration in the forebrain of the leopard gecko (Eublepharis macularius) following neurochemical lesioning.

Neurogenesis is the ability to generate new neurons from resident stem/progenitor populations. Although often understood as a homeostatic process, several species of teleost fish, salamanders, and lacertid lizards are also capable of reactive neurogenesis, spontaneously replacing lost or damaged neurons. Here, we demonstrate that reactive neurogenesis also occurs in a distantly related lizard species, Eublepharis macularius, the leopard gecko. To initiate reactive neurogenesis, the antimetabolite 3-acetylpyridine (3-AP) was administered. Four days following 3-AP administration there is a surge in neuronal cell death within a region of the forebrain known as the medial cortex (homolog of the mammalian hippocampal formation). Neuronal cell death is accompanied by a shift in resident microglial morphology and an increase neural stem/progenitor cell proliferation. By 30 days following 3-AP administration, the medial cortex was entirely repopulated by NeuN+ neurons. At the same time, local microglia have reverted to a resting state and cell proliferation by neural stem/progenitors has returned to levels comparable with uninjured controls. Together, these data provide compelling evidence of reactive neurogenesis in leopard geckos, and indicate that the ability of lizards to spontaneously replace lost or damaged forebrain neurons is more taxonomically widespread and evolutionarily conserved than previously considered.

Epidermal Cyst on the Head of a Leopard Gecko (Eublepharis macularius)

Abstract An estimated 6-yr-old female leopard gecko (Eublepharis macularius) presented with a raised spherical mass on the head. Grossly, the skin overlying the mass was smooth, with a focal area of ulceration. Histologically, the dermis was expanded by a well-demarcated, poorly cellular single expansile cyst. The cyst was lined by stratified squamous epithelium and was filled with an accumulation of tightly packed lamellar keratin with regular folding, resembling keratinization of the epidermis. Neither cellular nor nuclear atypia was observed, and there were no mitotic figures in the lining epithelium. The histopathological findings were consistent with an epidermal cyst. To the best of the authors' knowledge, an epidermal cyst in the dermis of the head has not been documented previously in a captive leopard gecko.

Radial Glia and Neuronal-like Ependymal Cells Are Present within the Spinal Cord of the Trunk (Body) in the Leopard Gecko (Eublepharis macularius).

As is the case for many lizards, leopard geckos (Eublepharis macularius) can self-detach a portion of their tail to escape predation, and then regenerate a replacement complete with a spinal cord. Previous research has shown that endogenous populations of neural stem/progenitor cells (NSPCs) reside within the spinal cord of the original tail. In response to tail loss, these NSPCs are activated and contribute to regeneration. Here, we investigate whether similar populations of NSPCs are found within the spinal cord of the trunk (body). Using a long-duration 5-bromo-2′-deoxyuridine pulse-chase experiment, we determined that a population of cells within the ependymal layer are label-retaining following a 20-week chase. Tail loss does not significantly alter rates of ependymal cell proliferation within the trunk spinal cord. Ependymal cells of the trunk spinal cord express SOX2 and represent at least two distinct cell populations: radial glial-like (glial fibrillary acidic protein- and Vimentin-expressing) cells; and neuronal-like (HuCD-expressing) cells. Taken together, these data demonstrate that NSPCs of the trunk spinal cord closely resemble those of the tail and support the use of the tail spinal cord as a less invasive proxy for body spinal cord injury investigations.

Description of a new species of leopard geckos, Eublepharis Gray, 1827 from Eastern Ghats, India with notes on Eublepharis hardwickii Gray, 1827

A recent molecular phylogenetic study of the genusEublepharisGray, 1827 revealed the presence of a genetically divergent lineage sister toEublepharis hardwickiiGray, 1827. We re-assessed the taxonomy ofEublepharis hardwickiibased on museum material in light of the molecular phylogenetic study and the results support the recognization of two species distributed on either sides of the Brahmani River. A redescription ofE. hardwickiiis presented based on the holotype and additional museum material along-with the description of a new species,Eublepharis pictussp. nov.from Andhra Pradesh and Odisha. The presence of yet another distinct lineage in such close geographical proximity in the northern Eastern Ghats highlights the significance of these relic forests and advocates the need for conservation prioritization.

Rare Occurrence of Blastocystis in Pet Animals and Their Owners in the Pomeranian Voivodeship in Poland in the Light of Literature Data.

Blastocystis is an intestinal microeukaryote with ambiguous pathogenicity, commonly detected in human feces worldwide. It comprises at least 28 genetically diverse subtypes (STs), 12 of which also occur in a wide range of animal species, giving rise to suspicion of zoonotic transmission. To investigate this, we conducted a molecular study of 145 stool samples of pet animals, and 67 of their owners, living in an urban area in Poland. Blastocystis was detected in only three (2.1%) animal samples (of two bearded agamas and a leopard gecko), while all dogs, cats, and pet rodents were Blastocystis-negative. Blastocystis was also present in three (4.5%) owners of animals, but they were cat owners, not reptile owners, and the subtypes identified in them differed significantly from those of reptiles. Additionally, the frequency of Blastocystis in different groups of dogs (depending on how they were kept) was analyzed. This work is the first to find Blastocystis in pet reptiles, and we encourage further investigation of Blastocystis in this poorly examined group of animals, as well as continued study on the transmission of this microorganism between humans and animals.

Cryptosporidium in Leopard Gecko: A case report

The choice for so-called “unconventional” animals has grown a lot in recent times and reptiles have gained popularity as pets. The Leopard Gecko (Eublepharis macularius) has been much sought after for breeding in captivity, and is currently one of the most adopted lizards in the world. However, most reptiles in captivity are acquired illegally, without information related to management, which triggers the onset of diseases such as cryptosporidiosis. Cryptosporidium are obligate intracellular coccidia protozoa that reproduce in the epithelial cells of the small intestine of a host via the fecal-oral route and contamination in Eublepharis macularius can cause fatal diarrheal disease. In this study, we report the first case, in Brazil, of an extremely debilitated specimen of Leopard Gecko, which died and was referred for cadaveric examination at the pathology laboratory at Unb, with suspicion of Cryptosporidium. Based on the results obtained in the autopsy report, the animal's cause of death was due to parasitism caused by Cryptosporidium sp.

Does colour impact responses to images in geckos?

AbstractAnimals are exposed to different visual stimuli that influence how they perceive and interact with their environment. Visual information such as shape and colour can help animals detect, discriminate, and make appropriate behavioural decisions for mate selection, communication, camouflage, and foraging. Previous research indicates that at least some species within all major vertebrate groups prefer and can discriminate among certain colours and that colour may increase the response to a stimulus. However, since colour is often studied together with other potentially confounding factors such as movement and scent, it is still unclear what role colour plays in the perception of and attention to different stimuli. In this study, we test whether colour influences the response that an animal has to an object, and whether this influence changes depending on the type of object shown to the animal. We assessed the response of three gecko species,Correlophus ciliatus,Eublepharis macularius,andPhelsuma laticauda, to familiar and novel objects presented as colour or grayscale images. Our results indicate that colour does not change the response to objects. Specifically, we found that while all species responded more often to novel than to the familiar images, colour did not influence the response. We also found that the duration of interaction with images was significantly longer for the diurnal species,P. laticauda, than for the two nocturnal species, but this was also independent of colouration. Finally, no differences among sexes were observed within or between species. Our results show that geckos discriminate between 2D images of different content independent of colouration, suggesting that colour may not increase detectability or intensity of the response. These results are essential for uncovering which visual stimuli produce responses in animals.

The evolutionary history of an accidental model organism, the leopard gecko Eublepharis macularius (Squamata: Eublepharidae)

The leopard gecko, Eublepharis macularius, is a widely used model organism in laboratory and experimental studies. The high phenotypic diversity in the pet trade, the fact that the provenance of different breeding lines is unknown, and that distinct Eublepharis species are known to hybridize, implies that the continued use of E. macularius as a model requires clarity on the origin of the lineages in the pet trade. We combine multi-locus sequence data and the first range-wide sampling of the genus Eublepharis to reconstruct the evolutionary history of the Eublepharidae and Eublepharis, with an updated time-tree for the Eublepharidae. Our sampling includes five of the six recognized species and additional nominal taxa of uncertain status comprising 43 samples from 34 localities plus 48 pet-trade samples. The Eublepharidae began diversifying in the Cretaceous. Eublepharis split from its sister genera in Africa in the Palaeocene-Eocene, and began diversifying in the Oligocene-Miocene, with late Miocene-Pliocene cladogenesis giving rise to extant species. The current species diversity within this group is moderately underestimated. Our species delimitation suggests 10 species with four potentially unnamed divergent lineages in Iran, India and Pakistan. All 30 individuals of E. macularius that we sampled from the pet trade, which include diverse morphotypes, come from a few shallow E. macularius clades, confirming that lab and pet trade strains are part of a single taxon. One of the wild-caught haplotypes of E. macularius, from near Karachi, Pakistan, is identical to (10) pet-trade samples and all other captive populations are closely related to wild-caught animals from central/southern Pakistan (0.1–0.5 % minimum pairwise uncorrected ND2 sequence divergence).

Coproparasitologic survey of gastrointestinal parasites in a captive leopard geckos collection (Eublepharis macularius).

An increase in exotic animal imports has been noticed in the last decades worldwide. In this scenario, reptiles represent a quite popular group of interest as exotic pets. However, they can harbor pathogens that under inadequate captivity conditions can lead to disease expression and sometimes death. This study performed coprological analysis to investigate gastrointestinal parasites in a private collection of leopard geckos (E. macularius) relating the results with husbandry practices. Twenty-three geckos of 1 to 5years, weighing 30-65g, of both sexes were used. Freshly voided fecal samples were collected and centrifugal fecal float technique was performed using Sheather's sugar solution. 65,21% animals were positive for gastrointestinal parasites. No animal presented any clinical signs but previous loss was reported in the colony. Among affected animals, 93,3% presented oxyurid eggs, 33,33% Strongyloidea eggs and 26,66% presented mite eggs. Four animals were infected with both nematodes. The groups found are commonly reported in captive reptiles and, due to their direct life cycle, reinfection is common in captive animals. The husbandry practices proved to be insufficient and preventive measures such as quarantine were not adopted by the owner, which can compromise not only the reptiles health but also people who deal with them.

Evaluation of Euthanasia Methods Using Injectable Agents in Leopard Geckos (Eublepharis macularius)

Reptile euthanasia techniques are poorly described. This non-blinded randomized study compared pentobarbital, lidocaine, and potassium chloride (KCl) for leopard geckos (Eublepharis macularius) euthanasia at 20° Celsius and evaluated for post-mortem artifacts. Fifty-three non-clinical adult leopard gecko were scheduled for euthanasia due to Cryptosporidium varanii exposure. Based on pilot study results, geckos randomly received one of six treatments: intracoelomic (ICo) pentobarbital 400mg/kg (ICo-P4, n = 9) or 800mg/kg (ICo-P8, n = 9), intramuscular (IM) alfaxalone 20mg/kg followed by intracardiac (ICa) pentobarbital 800mg/kg (ICa-P, n = 9), KCl 10mEq/kg (ICa-K, n = 9), or lidocaine 100mg/kg (ICa-L, n = 9) or IM alfaxalone 20mg/kg (IM-A, n = 8, control). Serial Doppler heart rate assessments were performed until cardiac arrest, 30 minutes (ICa groups), or 60 minutes (ICo groups). Cardiac arrest occurred in 7/9, 9/9, 9/9, 8/9, and 8/9 geckos in ICo-P4, ICo-P8, ICa-P, ICa-K, and ICa-L, respectively, with median (range) times of 35 (25 - 45), 30 (15-60), 0 (0 - 6.33), 0 (0 - 0.05), and 0 (0 - 0.03) minutes. Side effects were noted in a subset of ICo-P (arched posture) and ICa-K (muscle spasms) geckos. Six geckos in ICa-L had Doppler sound resumption several hours following cessation, with three displaying spontaneous movement. All geckos in IM-A recovered. Intracardiac pentobarbital following IM alfaxalone caused rapid, permanent loss of heartbeat in all tested geckos. Intracoelomic pentobarbital was also effective but had a prolonged time to cardiac arrest. Intracardiac lidocaine is not recommended for leopard gecko euthanasia.

Measuring the Effects of a Single Dose of Human Chorionic Gonadotropin (hCG) on Plasma Testosterone Concentrations in Leopard Geckos (Eublepharis macularius)

Current estimates suggest that one-fifth of all reptiles are currently threatened with extinction because of anthropogenic activity, and that if nothing is done to mitigate these impacts, massive extinctions will occur over the coming decades. Assisted reproductive technologies (ART) can be used to develop ex vivo conservation programs to ensure species survival until environmental deficiencies can be corrected. Geckos represent one of the most diverse groups of reptiles on earth and need protection; however, to date, no ART have been developed for these animals. Exogenous human chorionic gonadotropin (hCG) is routinely used to alter reproductive hormones of vertebrates and are integrated in ART. The purpose of this study was to determine if a single dose of hCG could increase plasma testosterone concentrations in the leopard gecko (Eublepharis macularius) within 24 h of administration. The study was performed in September, which is considered the nonbreeding season for this species in the northern hemisphere. Twelve captive-bred, adult, male leopard geckos were randomly divided into three treatment groups and administered an intramuscular injection of hCG (50 or 100 IU) or saline. Whole blood was collected prior to injection (baseline) and 12 and 24 h after injection. Plasma testosterone concentrations were measured using an enzyme immunoassay kit. There was no significant difference (P = 0.195) in testosterone concentrations between treatment groups. Because there was no difference, an observed testosterone range (61.0 ± 42.5, 5.5–149.0) for September was calculated. These results suggest that captive leopard geckos may be in a recrudescence phase in September in the northern hemisphere.

Capturing and analyzing pattern diversity: an example using the melanistic spotted patterns of leopard geckos

Animal color patterns are widely studied in ecology, evolution, and through mathematical modeling. Patterns may vary among distinct body parts such as the head, trunk or tail. As large amounts of photographic data is becoming more easily available, there is a growing need for general quantitative methods for capturing and analyzing the full complexity and details of pattern variation. Detailed information on variation in color pattern elements is necessary to understand how patterns are produced and established during development, and which evolutionary forces may constrain such a variation. Here, we develop an approach to capture and analyze variation in melanistic color pattern elements in leopard geckos. We use this data to study the variation among different body parts of leopard geckos and to draw inferences about their development. We compare patterns using 14 different indices such as the ratio of melanistic versus total area, the ellipticity of spots, and the size of spots and use these to define a composite distance between two patterns. Pattern presence/absence among the different body parts indicates a clear pathway of pattern establishment from the head to the back legs. Together with weak within-individual correlation between leg patterns and main body patterns, this suggests that pattern establishment in the head and tail may be independent from the rest of the body. We found that patterns vary greatest in size and density of the spots among body parts and individuals, but little in their average shapes. We also found a correlation between the melanistic patterns of the two front legs, as well as the two back legs, and also between the head, tail and trunk, especially for the density and size of the spots, but not their shape or inter-spot distance. Our data collection and analysis approach can be applied to other organisms to study variation in color patterns between body parts and to address questions on pattern formation and establishment in animals.

The effect of climate change on habitat suitability and a distribution model of the Iranian fat-tailed gecko, Eublepharis angramainyu Anderson and Leviton, 1966 (Sauria: Eublepharidae) since the Last Interglacial to 2050

Surveying the role of climate changes on the species distributions in the past, present and future, and correlating these with changes in distribution ranges have attracted considerable research interest. The leopard geckos of the genus Eublepharis Gray, 1827 (family Eublepharidae), as a vicariate group, comprises six valid species distributed from Turkey through the Iranian Plateau to India, of which E. angramainyu, E. macularius and E. turcmenicus occur in Iran. In this study, we modelled the potential distribution areas for E. angramainyu and determined the suitable habitats in the past (the last interglacial [LIG] and mid-Holocene [MH]), present (1950–2000), and also predicted four scenarios in the future (2050) by using the maximum entropy approach (MaxEnt). The obtained models indicated very good values of the area under curve (AUC): LIG = 0.996 ± 0.003, MH = 0.996 ± 0.004, contemporary period = 0.995 ± 0.004, and the future = 0.997 ± 0.002. Precipitation of the coldest quarter and precipitation of the warmest quarter were the most important factors shaping the distribution of E. angramainyu. As it seems, climatic changes have been responsible for a southward shift in distribution and suitable habitats of E. angramainyu from the LIG (~150,000–120,000 years ago) to the future. The representative concentration pathway (RCP) 2.6 scenario model of the future predicted a much more restricted distribution and less suitable habitats due to radiation of the forcing level which reaches a value of around 3.1 W/m² by mid-century and returns to 2.6 W/m² by 2100.