Bacterial infection theranostics combining antibacterial therapy and real-time diagnosis can effectively advance the healing process. Near-infrared (NIR) light has been widely utilized for antibacterial photothermal therapy (PTT) and visible light can provide visual cues for the status of treatment, whereas the lack of modulating light propagation hinders the development of high-performance light-based infection theranostics. Here, inspired by the hierarchical micro/nano-structures of panther chameleon skin composed of deep- and superficial-iridophores responsible for regulating NIR and visible light propagation, respectively, a photonic crystal hydrogel is developed for enhanced antibacterial PTT and colorimetric monitoring of pH and treatment temperature. The deep layer composed of large-sized particles in the hyaluronic acid methacryloyl-polyacrylamide hydrogel matrix exhibits a photonic bandgap overlapping NIR light, acting as a universal platform for boosting the photothermal conversion efficiency (PCE) of embedded photothermal agents. As typical examples, 1.75-, 1.80-, and 1.94-fold increases in PCEs are achieved for embedded carbon black, carbon nanotubes, and MXenes, respectively. The superficial layer consisting of small-sized particles and a poly(2-(dimethylamino)ethyl methacrylate) hydrogel matrix is responsible for visible light modulation, exhibiting rapid, high-sensitivity, and broad-range color variations at different pH/temperatures. Benefiting from these light modulation capabilities, high-efficacy and multifunctional bacterial infection theranostics are realized, synergistically facilitating the healing of infected wounds.

ABSTRACTThe assessment of the urogenital tract is of great importance in the diagnosis of diseases in lizards, and sonographic examination is the most suitable imaging method for this purpose. However, reference data are not available for most of the commonly kept species. The objective of this prospective anatomical analytical study was to sonographically examine the urogenital tract of four of the most commonly kept lizard species and compare their kidneys, testes, and ovaries. A total of 41 lizards, 14 bearded dragons (Pogona vitticeps), 15 leopard geckos (Eublepharis macularius), seven veiled chameleons (Chamaeleo calyptratus), and five panther chameleons (Furcifer pardalis) were included. An 8–18 MHz field hockey stick transducer and a 6–15 MHz linear transducer were used. Sagittal and transverse images of the organs were recorded. The kidneys could be visualized and assessed in full length in all lizards, the testes in 18 of 19, and the ovaries in 13 of 22 lizards. The results of the current study could serve as reference values for future studies on the species mentioned.

Granulomatous pneumonia caused by Mycobacterium simiae and necroulcerative enteritis caused by Entamoeba spp in a panther chameleon (Furcifer pardalis)

The emergence of ophidiomycosis (or snake fungal disease) in snakes has prompted increased awareness of the potential effects of fungal infections on wild reptile populations. Yet, aside from Ophidiomyces ophidiicola, little is known about other mycoses affecting wild reptiles. The closely related genus Paranannizziopsis has been associated with dermatomycosis in snakes and tuataras in captive collections, and P. australasiensis was recently identified as the cause of skin infections in non-native wild panther chameleons (Furcifer pardalis) in Florida, USA. Here we describe five cases of Paranannizziopsis spp. associated with skin lesions in wild snakes in North America and one additional case from a captive snake from Connecticut, USA. In addition to demonstrating that wild Nearctic snakes can serve as a host for these fungi, we also provide evidence that the genus Paranannizziopsis is widespread in wild snakes, with cases being identified in Louisiana (USA), Minnesota (USA), Virginia (USA), and British Columbia (Canada). Phylogenetic analyses conducted on multiple loci of the fungal strains we isolated identified P. australasiensis in Louisiana and Virginia; the remaining strains from Minnesota and British Columbia did not cluster with any of the described species of Paranannizziopsis, although the strains from British Columbia appear to represent a single lineage. Finally, we designed a pan-Paranannizziopsis real-time PCR assay targeting the internal transcribed spacer region 2. This assay successfully detected DNA of all described species of Paranannizziopsis and the two potentially novel taxa isolated in this study and did not cross-react with closely related fungi or other fungi commonly found on the skin of snakes. The assay was 100% sensitive and specific when screening clinical (skin tissue or skin swab) samples, although full determination of the assay’s performance will require additional follow up due to the small number of clinical samples (n = 14 from 11 snakes) available for testing in our study. Nonetheless, the PCR assay can provide an important tool in further investigating the prevalence, distribution, and host range of Paranannizziopsis spp. and facilitate more rapid diagnosis of Paranannizziopsis spp. infections that are otherwise difficult to differentiate from other dermatomycoses.

Structural colors in nature are frequently produced by the ordered arrangement of nanoparticles. Interesting examples include reptiles and birds utilizing lattice-like formation of nanoparticles to produce a variety of colors. A famous example is the panther chameleon which is even able to change its color by actively varying the distance between guanine nanocrystals in its skin. Here, we demonstrate that the application of rigorous electromagnetic methods is important to determine the actual optical response of such biological systems. By applying the Korringa-Kohn-Rostoker (KKR) method we calculate the efficiencies of the reflected diffraction orders that can be viewed from directions other than the specular. Our results reveal that important characteristics of the reflectance spectra, especially within the ultraviolet (UV) and short visible wavelengths region, cannot be predicted by approximate models like the often-applied Maxwell-Garnett approach. Additionally, we show that the KKR method can be employed for the design of multi-layer structures with a desired optical response in the UV regime.

Chameleons are famous for their quick color changing abilities, and it is commonly assumed that they do this for camouflage. However, recent reports revealed that chameleons also change color for body temperature regulation. Inspired by the structure of the panther chameleon's skin, a stripe-patterned poly(N-isopropylacrylamide) (PNIPAM) and polyacrylamide (PAM) hydrogel film with a laminated structure is fabricated in this work; thus, both camouflage and thermoregulation can be achieved through controlling Vis and NIR light effectively. For the PNIPAM stripe, the upper layer is the native PNIPAM hydrogel and the lower layer is the carbon nanotube-composited PNIPAM hydrogel. Thus, the PNIPAM stripe is capable of reaching 28 °C at a low environmental temperature (12 °C) and a low radiation intensity (20 mW cm-2), while preventing the body temperature from rising by changing to white under a strong radiation intensity (100 mW cm-2). For the PAM stripe, the upper layer combines colloidal photonic crystals and displays a tunable structural color by stretching, and the lower layer is mixed with PNIPAM microgels for thermal regulation. Through the fabrication of multifunctional patterns, the film can achieve both dynamic structural color and thermoregulation by precisely controlling solar radiation absorption, scattering, and reflection. More importantly, in the stripe-patterned system, the shrinkage of the PNIPAM stripes can effectively trigger the elongation of the PAM stripe, which endows the structural color changing process to be self-powered completely. The performances show that the stripe-patterned film may have potential applications in intelligent coatings, especially in areas with large temperature differences during the day such as high plains.

Predicting potential distributions of species in new areas is challenging. Physiological data can improve interpretation of predicted distributions and can be used in directed distribution models. Nonnative species provide useful case studies. Panther chameleons (Furcifer pardalis) are native to Madagascar and have established populations in Florida, USA, but standard correlative distribution modeling predicts no suitable habitat for F. pardalis there. We evaluated commonly collected thermal traits– thermal performance, tolerance, and preference—of F. pardalis and the acclimatization potential of these traits during exposure to naturally-occurring environmental conditions in North Central Florida. Though we observed temperature-dependent thermal performance, chameleons maintained similar thermal limits, performance, and preferences across seasons, despite long-term exposure to cool temperatures. Using the physiological data collected, we developed distribution models that varied in restriction: time-dependent exposure near and below critical thermal minima, predicted activity windows, and predicted performance thresholds. Our application of commonly collected physiological data improved interpretations on potential distributions of F. pardalis, compared with correlative distribution modeling approaches that predicted no suitable area in Florida. These straightforward approaches can be applied to other species with existing physiological data or after brief experiments on a limited number of individuals, as demonstrated here.

Background:Veiled chameleon (Chamaeleo calyptratus) and panther chameleon (Furcifer pardalis) are two of the most popular pet chameleons, and consequently, these species are frequently evaluated in veterinary practices. According to our review of the literature, normal computed tomography (CT) anatomy of these lizards has not been previously described. Aim:The purposes of this prospective study were to describe the normal CT anatomy of the coelomic organs in healthy patients and to provide normal reference values in these species. Methods:Seventeen clinically healthy veiled chameleons and 15 clinically healthy panther chameleons were included. All CT studies were performed with the chameleons under light anesthesia and positioned in sternal recumbency. Studies were performed with a 16-slice helical CT scanner with a slice thickness of 0.625 mm. The authors recorded qualitative and quantitative CT characteristics of the coelomic structures. Macroscopic cross-sectional anatomy was performed for comparison of the CT findings.Results:Heart, lungs, liver, including caudal vena cava, hepatic vessels, gallbladder, esophagus, stomach, intestines, gonads, fat bodies, kidneys, and urinary bladder could be visualized with CT. The spleen, pancreas, and adrenal glands could not be identified. Conclusion:This study provides a guide to the normal cross-sectional and computed tomographic anatomy of the coelomic cavity in veiled and panther chameleons. Our results could be used as a reference for future research studies or comparison of clinically ill patients.

Most amniote genomes are diploid, moderate in size (approximately 1-6 Gbp), and contain a large proportion of repetitive sequences. The development of next-generation sequencing technology, especially the emergence of high-fidelity (HiFi) long-read data, has made it feasible to resolve high-quality genome assembly for non-model species efficiently. However, reference genomes for squamate reptiles has lagged behind other amniote lineages. Here we de novo assembled the first genome from the Chameleonidae family, the panther chameleon (Furcifer pardalis). We obtained telomere-to-telomere contigs using only HiFi data, reaching a contig N50 of 158.72 Mbp. The final chromosome-level assembly is 1.61 Gbp in size and 100% of primary contigs were placed to pseudochromosomes using Hi-C interaction data. We also found that sequencing depth > 30 folds can ensure both the integrity and accuracy of the genome, while insufficient depth led to false increase in genome size and proportion of duplicated genes. We provide a high-quality reference genome valuable for evolutionary and ecological studies in chameleons as well as providing comparative genomic resources for squamate reptiles.

Emergent fungal pathogens in herpetofauna are a concern in both wild and captive populations. We diagnosed dermatomycosis by Paranannizziopsis australasiensis in two panther chameleons (Furcifer pardalis) and suspected it in eight others captured from an established free-living nonnative population in Florida, USA. Chameleons developed skin lesions following recent exposure to cold weather conditions while housed in captivity, approximately 10 mo after capture and 12 wk after being placed in outdoor enclosures. Affected animals were treated with oral voriconazole and terbinafine until most cases resolved; however, medications were ultimately discontinued. Paranannizziopsis australasiensis has not previously been described in chameleons, nor in animals originating from a free-ranging population in the USA. Although the source of P. australasiensis infection is uncertain, we discuss several scenarios related to the pet trade and unique situation of chameleon "ranching" present in the USA.

Simple SummaryTumors of the skin are one of the most commonly observed neoplasms in captive lizards. The current study characterizes keratoacanthoma, a previously undescribed skin tumor, in five male lizards (one bearded dragon, one veiled chameleon, and three panther chameleons) with an average to high age. In all lizards, keratoacanthomas presented as cystic nodules with a central keratin pearl that was predominantly located at the body wall. In all chameleons, a multicentric distribution was observed. Following surgical removal of the keratoacanthomas in all lizards, a follow-up period of one to two years was established. While the skin neoplasia reappeared in the bearded dragon and the veiled chameleon, no recurrence was seen in the panther chameleons. Keratoacanthoma constitutes a rather benign histologic variant of squamous cell carcinoma, representing a non-invasive but rapidly growing skin neoplasia that may be associated with the inappropriate use of ultraviolet lighting in the captive environment. In addition, panther chameleons may show a species predisposition as well as a tendency to develop multicentric keratoacanthomas. The present study delivers pertinent results for the diagnosis, prevention, and treatment of keratoacanthomas in lizards.The present study describes the clinical behavior as well as the histopathologic and immunohistochemical characteristics of keratoacanthomas (Kas) in three different saurian species. While Kas presented as two dermal lesions in a bearded dragon (Pogona vitticeps), multicentric Kas were observed in three panther chameleons (Furcifer pardalis) and a veiled chameleon (Chamaeleo calyptratus). Macroscopically, Kas presented as dome-shaped skin tumors with a centralized keratinous pearl and a diameter ranging from 0.1–1.5 cm. In all lizards, Kas were predominantly located at the dorsolateral body wall, and KA of the eyelid was additionally observed in three out of four chameleons. Histologically, KAs presented as relatively well-defined, circumscribed epidermal proliferations that consisted of a crateriform lesion containing a central keratinous pearl with minimally infiltrating borders. In all KAs, a consistent immunohistochemical pattern was observed, with the expression of cyclooxygenase-2, E-cadherin, and pan-cytokeratin. A follow-up period of one to two years was established in all lizards. While no recurrence was observed in the panther chameleons, recurrence of a single keratoacanthoma was observed in the bearded dragon after one year, and in the veiled chameleon, multicentric keratoacanthomas reappeared during a follow-up period of two years. We describe KA as a previously unrecognized neoplastic entity in lizards that constitutes a low-grade, non-invasive but rapidly growing skin tumor that may show a multicentric appearance, especially in chameleons. As previously postulated for dermal squamous cell carcinomas (SCC), artificial ultraviolet lighting may play an important role in the oncogenesis of KAs in lizards. Although dermal SCCs in lizards show similar predilection sites and gross pathologic features, our results suggest that KA should be considered as a histologic variant of SCC that represents a rather benign squamous proliferation in comparison to conventional SCCs. Early diagnosis of KA and reliable discrimination from SCCs are essential for the prognosis of this neoplastic entity in lizards.

Chameleons represent one of the most endangered groups of lizards, with most being characterized as threatened or near-threatened. Anthropogenic impacts on their native habitat are responsible for their declines. To protect these animals, we must develop functional assisted reproductive programs. However, a full understanding of their basic reproductive biology is required to develop such a program. This study represents the first attempt at characterizing the reproductive cycles of male chameleons. Sixteen veiled chameleons (Chamaeleo calyptratus) and 16 panther chameleons (Furcifer pardalis) being housed in captivity under static conditions were used for this study. Chameleons were anesthetized twice monthly for semen collection via electroejaculation, blood sampling to measure plasma testosterone concentrations, and ultrasonographic testicular measurements. Plasma testosterone concentrations were found to be significantly different between species (P = 0.02) and the interaction of species and month (P = 0.04). In veiled chameleons, plasma testosterone concentrations were significantly elevated during October through December, while for panther chameleons, plasma testosterone concentrations were elevated in July through September, and December. Electroejaculation success was found to be seasonal in both species. In veiled chameleons, semen collection was highest in April, May, and June, while in panther chameleons semen collection success was highest in March, April, May, and June. Median spermatozoa concentrations for veiled and panther chameleons were 6.66 and 7.52 x 107 million sperm/mL, respectively. Motility was lower than expected for both veiled chameleon (median 23%) and panther chameleons (median 25%). Spermatozoa clumping was a common finding. The majority of the spermatozoa (mean 51%) were...

Chameleons are famous for their uncommon ability to change skin colors rapidly by tuning the lattice distance of guanine nanocrystals within the dermal iridophores. This mechanism has inspired various artificial photonic crystal (PC) films with tunable structural colors. However, the structural colors of most reported films are facile to be destroyed by external factors such as friction, impact, or water evaporation. Herein, an artificial intelligent skin, which has an elastomer–colloidal photonic crystal–hydrogel sandwich structure, is presented in this work. The outer modified polydimethylsiloxane layer acts as the cuticle to protect the hydrogel layer from water evaporation and endows the skin with self-healing ability. The inner hydrophilic hydrogel layer embedded with the colloidal photonic crystals acts as the dermis layer, and the polystyrene colloids layer plays the role of the guanine nanocrystals. A programmed color change can be easily controlled by varying the elongation of the artificial skin, covering the full visible spectrum range. Moreover, skin with patterned stripes, which is similar to the panther chameleon skin that can manipulate multiple colors, has also been achieved. The present artificial skin will offer fresh perspectives on the preparation of artificial chameleon skin similar to the real dynamic flexible skin, which would promote the application of PCs in optical devices.

In many animals, males engage in agonistic interactions. Color signals are commonly used to mitigate these potentially harmful interactions. Both pigment-based color and structural color, notably ultraviolet coloration, are used in this context to convey information, including an animal's resource holding potential (RHP) or social status. Despite extensive previous work on this topic, the ability to change color in this context has received relatively little attention. Moreover, no studies have considered the visible and the ultraviolet components of this ability. Thus, whether changes in ultraviolet play a role in settling intraspecific disputes remains unknown. Here, we investigate the role of color change during intrasexual agonistic interactions in male panther chameleons (Furcifer pardalis). To do so, we combined behavioral experiments and color analysis. Our results show that the outcome of male intrasexual agonistic interactions depends on particular aspects of color change in the visible spectrum. Dominant males exhibit more brightness changes and Euclidian distance changes within the HSV color space at the level of the bands and interbands, suggesting a prominent role of these patterns in panther chameleon communication. Our results also align with previous studies in another chameleon species, thus supporting the key role of brightness changes in chameleon communication, at least in a competitive context. Interestingly, although our species did exhibit UV coloration, neither this coloration nor its changes seem to be involved in intrasexual agonistic interactions among males, possibly because those signals may be used for other purposes like attracting mates, repelling predators, or deception.

Abstract A 3-yr-old female panther chameleon (Furcifer pardalis) was presented with a history of long-term inactivity, anorexia, and difficulty defecating. Using sonographic examination, we diagnosed preovulatory follicular stasis with suspected ovarian cysts. Surgical management was elected, and the ovaries were intertwined and showed severe torsion and morphologic changes. The colon was caught within the entanglement, resulting in obstipation and urate retention. After ovariectomy, the animal was able to pass feces 17 h postsurgery and regained appetite. Preovulatory follicular stasis, as well as constipation, are commonly seen conditions in reptiles; however, torsions are rarely described.

In this work, a free-standing microgel film with programmable and angle-independent structural color is prepared via a simple but effective method. Dried poly(styrene-N-isopropylacrylamide-acrylic acid) (pStNIPAAmAA) microgels were stabilized by inter-microgel crosslinking, and thus, only microgels were used to build the optical hydrogel. The free-standing microgel film displayed tunable structural color by the swelling/deswelling of the microgels under external stimuli, such as temperature, pH, ionic strength, and organic solvent. Moreover, the structural color of the film is angle-independent for the disordered microgel arrays. It is worth noting that programmable color stripes which have the panther chameleon's ability to change skin color are successfully fabricated by patterning microgels with different thermoresponsivities. More importantly, the microgel film has an ultrafast response to temperature (1.41 s from 20 to 40 °C) and pH (2.24 s from pH 8.3 to pH 2.0), much faster than that of most optical materials reported in previous studies.

A panther chameleon skin-inspired core@shell supramolecular hydrogel with spatially organized multi-luminogens enables programmable color change

Abstract 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.

While we generally understand the optimal ultraviolet B (UVB) environment for the growth and reproduction of female Panther Chameleons Furcifer pardalis, we do not know the relative importance of UVB irradiance and dose for optimal husbandry outcomes. Accordingly, we experimented with Panther Chameleon females to test the hypothesis that UVB dose (irradiance × exposure duration) determines the outcome, regardless of the combination of UVB irradiance and exposure duration generating the dose. We varied UVB irradiance and exposure duration across treatment groups while keeping dose similar and within a range previously documented to result in reproductive success. The growth rate, age of maturity, and measurable vitamin D status were not significantly different among the treatment groups. Individuals in all groups produced viable eggs that successfully hatched. Thus, we found some support for the hypothesis that the UVB dose determines the outcome regardless of UVB irradiance. However, mean egg vitamin D3 concentration and percent hatching were higher in the highest UVB irradiance group, despite similar doses among the three groups. Preliminary field data reveal that this species occupies UV irradiance Zone 4 in Madagascar, the highest zone for reptiles recorded. Only the irradiance of the high UVB irradiance group in our experiment approached this zone and resulted in the best reproductive success. Biosynthesis of vitamin D3 and provisioning to eggs is more efficient when exposure to UVB irradiance is similar to that in their natural environment. Establishing an optimal UVB environment, based on knowledge of the natural UVB environment, is important for the propagation of Panther Chameleons in captivity.

Cheilitis Associated with a Novel Herpesvirus in Two Panther Chameleons (Furcifer pardalis)