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We describe Baalemys mansillai gen. et sp. nov. a chelid turtle, based on an articulated shell from the Portezuelo Formation of the Baal locality, northern shore of Barreales lake, Neuquén Province, Argentina. Baalemys mansillai gen. et sp. nov. is distinguished from other chelids by its oval shape, moderate size, distinctive granulated ornamentation, narrow nuchal plate, first hexagonal neural with short posterolateral margins, a second neural plate that is a regular hexagon, and a posterior lobe that is longer than both the anterior lobe and the bridge. This unique combination of features supports the establishment of a new genus and species. Baalemys mansillai gen. et sp. nov was discovered in the Baal locality with sauropod dinosaurs, theropod dinosaurs, crocodiles, pelomedusoid turtles and other genera of chelids; a similar biota was identified in other localities of the Portezuelo Formation. The identification of Baalemys mansillai gen. et sp. nov. significantly adds to our knowledge of the diversity of pleurodiran turtles from the Portezuelo Formation, the Neuquén Basin, and the broader Patagonian region. [ABSTRACT FROM AUTHOR]

Chemical signaling through pheromones is an ancient and widespread mode of communication. Turtles and tortoises (chelonians) secrete pheromones via mental (chin) glands and have superior olfactory capacities rendering them a promising group to study the evolution and function of chemical communication in vertebrates. Here, we use state-of-the art proteomics and lipidomics techniques to identify and explore the possible functions of proteins and lipids secreted by mental glands in turtles. We examined four turtle species all from the family Geoemydidae, to understand among-species as well as sexual variation in the composition of mental gland secretions. Differential expression of a relatively small number (ca. 65) of proteins explained a large portion of the proteome variation across species, highlighting the existence of specific signals evolving even in closely related species. Lipidomic analysis revealed high inter-individual variation, but species differences could be attributed to five different lipid classes. The lipids found in mental glands could have a dietary origin or be related to individual condition, but may nonetheless be used in communication. We also examined sex-specific differences in the proteome of a single species (Mauremys leprosa) and found that males expressed a much larger array of proteins than females. Our findings establish a group of candidate proteins potentially involved in chemical signaling in freshwater geoemydid turtles. Alternatively, differently expressed proteins in mental glands could have an indirect link to chemical communication, being involved in pheromone transport and/or antioxidant protection. [ABSTRACT FROM AUTHOR]

The Journal of Herpetological Medicine & Surgery published a collection of peer-reviewed articles on infectious agents affecting reptiles and amphibians from January to July 2024. The research covers viruses, bacteria, fungi, and their impact on various species, offering insights into host-parasite interactions. The articles discuss parasitic infections, fungal diseases, bacterial infections, and helminth parasites in reptiles and amphibians, exploring topics like host response mechanisms and environmental influences on disease prevalence. The findings contribute to understanding parasite diversity, transmission dynamics, and potential treatment options for infected animals. [Extracted from the article]

Copyright of Mitteilungen des Deutschen Germanistenverbandes is the property of Vandenhoeck & Ruprecht GmbH & Co. KG and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Urbanization and fragmentation of habitat are major drivers of population declines in wildlife in cities. This study evaluated fragmentation of aquatic systems in the context of urbanization, using the Eastern long-necked turtle Chelodina longicollis as a model as it is a generalist species, highly vagile and engages in regular overland migration. During two seasons (2020-22), we compared C. longicollis demography in stormwater ponds in two distinct urban drainages, one with greater habitat connectivity (lower road network and an unmodified creek) and one with lower habitat connectivity (higher road network and stormwater drains) in Canberra, south-eastern Australia. Most of the parameters related to habitat (pond age and size) and food requirements (phosphate and prey biomass) for C. longicollis were similar between the two drainages, in addition to proportion of females, overall size-frequency distributions and population size (corrected for variation in capture probability). However, there was a significant effect of the interaction between pond habitat connectivity and pond size with population sizes increasing more steeply in higher than in lower connectivity sites (F1, 4 = 14.3, p = 0.02). We also recaptured a marked turtle from a previous study in the drainage with more habitat connectivity, 14 years later and 15 km from its initial point of capture. This demonstrates the ability of the species to move within an urbanized context. Despite evidence of C. longicollis being resilient to urbanization, dispersal constraints seem to affect population dynamics and long term population viability in areas with low habitat connectivity. [ABSTRACT FROM AUTHOR]

Classifying animal behaviors in their natural environments is both challenging and ecologically important, but the use of biologgers with multiple sensors has significantly advanced this research beyond the capabilities of traditional methods alone. Here, we show how biologgers containing an integrated tri-axial accelerometer, GPS logger and immersion sensor were used to infer behavioural states of a cryptic, freshwater turtle, the Blanding's turtle (Emydoidea blandingii). Biologgers were attached to three males and five females that reside in two undisturbed coastal marshes in northeastern Georgian Bay (Ontario, Canada) between May and July 2023. Raw acceleration values were separated into static and dynamic acceleration and subsequently used to calculate overall dynamic body acceleration (ODBA) and pitch. The unsupervised Hidden Markov Model (HMM) successfully differentiated five behavioural states as follows: active in water, resting in water, active out of water, resting in water, and nesting. Overall accuracy of the classification was 93.8%, and except for nesting (79%), all other behaviours were above 92%. There were significant differences in daily activity budgets between male and female turtles, with females spending a greater proportion of time active out of water, and inactive out of the water, while males spent a greater proportion of time active in water. These differences were likely a result of large seasonal life-history requirements such as nesting and mate finding. Accurate classification of behavioural states is important for researchers to understand fine-scale activities carried out during the active season and how environmental variables may influence the behaviours of turtles in their natural habitats. [ABSTRACT FROM AUTHOR]

Anthropogenic landscape change due to urbanization, agriculture, and resource extraction results in barriers within the landscape. Artificial structures such as roads, fences, levees, and dams limit the movement of some species and further fragment residual habitat. In this study, we investigated the ability of Eastern long‐necked turtles (Chelodina longicollis) to cross various terrestrial obstacles commonly encountered throughout their habitat. We tested two types of fences (chicken wire and hinged joint exclusion fencing) commonly used in agricultural systems and three sizes of rocks (gravel, cobbles, and boulders) often used for road construction, erosion control, and waterway stabilization. We examined the success rates of turtles in crossing obstacles, the effect of fatigue on crossing attempts, and the impact of individual boldness on movement behaviour. Turtles had high success rates in crossing gravel (85.4%), cobbles (86%), boulders (73.3%) and hinged joint exclusion fencing (94.7%). Turtles did not successfully cross chicken wire fencing (0%) despite 276 attempts. A significant fatigue effect occurred throughout the experiment, with turtles making an average of 3.94 (±1.42 SE) fewer attempts at the end of the experiment (day 18) than on day 1. Bolder turtles were faster at crossing obstacles, but boldness had no influence on obstacle‐crossing success. Our results highlight the need for thoughtful selection of waterway, wetland, and riparian bordering infrastructure and the fatiguing impact of constant exposure to anthropogenic barriers for wildlife. [ABSTRACT FROM AUTHOR]

The gut microbiota of vertebrates is malleable and may be shaped by both intrinsic and extrinsic factors. Here, the effect that geography has on the cloacal microbiota of two species of Australian freshwater chelonians, eastern longneck turtle (Chelodina longicollis) and Macquarie River turtle (Emydura macquarii), captured from waterbodies with different levels of anthropogenic pressure was investigated. We analysed the microbiota composition, structure and diversity through 16S rRNA gene amplicon sequencing. It was hypothesised that animals from less disturbed environments would harbour a more diverse cloacal microbial population. The cloacal microbiotas from 93 turtles (C. longicollis n = 78; E. macquarii n = 15), from five locations, were analysed. For both species, the most predominant phylum was Proteobacteria. Cloacal microbiota alpha diversity varied significantly between the C. longicollis from all locations, but no differences were found for E. macquarii. In C. longicollis, turtles from wetlands within the centre of Melbourne had the lowest alpha diversity metrics, while the highest alpha diversity values were seen in turtles captured from an undisturbed rural waterbody. Beta diversity, obtained by weighted UniFrac distance, showed significant differences between locations of capture for both species of turtles in this investigation. For C. longicollis, 87 biomarkers were identified responsible for explaining differences between locations, and in E. macquarii, 42 biomarkers were found. This is the first study to explore the cloacal microbiota composition of the eastern longneck turtle and gives greater insight into microbial community structures in Macquarie River turtles. Our study demonstrated that cloacal microbiota composition of freshwater turtles was significantly influenced by locality and that disrupted environments may reduce microbial diversity in C. longicollis. Interestingly, we discovered that the effects of location contrasted significantly between species for alpha diversity with differences discovered for C. longicollis but not E. macquarii. However, for both species, beta diversity was notably influenced by habitat type. These results highlight the need to interpret chelonian microbiota data in the context of geography and human disturbance of the environment. [ABSTRACT FROM AUTHOR]

South Africa is currently home to a highly diverse tortoise assemblage whose evolutionary history has been investigated mostly as a result of molecular studies. The fossil record is of little help because the remains of extant taxa are relatively recent, and only three extinct species, of uncertain relationships, have been described so far. An Early Pliocene extinct species of the currently monotypic genus Chersina , still inhabiting South Africa, was reported at the fossil-rich site of Langebaanweg more than 50 years ago but never formally described. Here we erect and describe the extinct species Chersina langebaanwegi sp. nov. on the basis of abundant material that provides information on its morphological variation. The referral of the new species to the genus Chersina is supported by phylogenetic analysis which includes the Malagasy ploughshare tortoise, sharing the presence of a single gular shield covering a very long gular protrusion with Chersina spp. and a domed shell with C. langebaanwegi sp. nov. The material from Langebaanweg represents the oldest fossil evidence of this genus. It significantly post-dates the branching of Chersina from its sister taxon Chersobius , but pre-dates the presumed split of the extant lineages of Chersina angulata as estimated on molecular basis. [ABSTRACT FROM AUTHOR]

Turtles have high shape variation of their mandibles, likely reflecting adaptations to a broad variety of food items and ingestion strategies. Here, we compare functional disparity measured by biomechanical proxies and character disparity measured by discrete morphological characters. Functional and character disparities vary between clades and ecological groups and are thus decoupled. Comparisons with cranial disparity also indicate decoupled patterns within the turtle skull. Exploration of mandibular patterns reveals that several biomechanical configurations or character state combinations can lead to the same feeding type (i.e., convergence) or that high functional disparity can be achieved at a low exhaustion of character state combinations (e.g., cryptodires). Dietary specialists show larger functional disparity than generalists, but the phylogenetically widespread generalist ecology leads to high character disparity signals in the ecotype. Whereas character disparity generally shows high phylogenetic signal, functional disparity patterns correspond to dietary specializations, which may occur convergently across different groups. Despite this, individual functional measurements have overlapping ranges across ecogroups and do not always conform to biomechanical expectations. Jaw opening and closing biomechanical advantages model trade‐offs between force transmission and opening/closing speeds, and turtles show a variety of combinations of values that we try to synthesize into several "jaw types". Closing mechanical advantage shows that turtles retain high levels of force transmission at the anterior jaw end compared with other groups (e.g., pseudosuchians). This can possibly be explained as an evolutionary adaptation to retain high bite forces at small head sizes. [ABSTRACT FROM AUTHOR]

Sex‐ratio theory predicts that parents can optimise their fitness by producing offspring of the rare sex, yet there is a dearth of empirical evidence for adaptive sex allocation in response to the adult sex ratio (ASR). This is concerning, as anthropogenic disruption of the sex ratios of reproductive individuals threatens to cause demographic collapse in animal populations. Species with environmental sex determination (ESD) are especially at risk but may possess the capacity to adaptively influence offspring sex via control over the developmental environment. For example, reptiles with temperature‐dependent sex determination (TSD) could conceivably choose nest sites with thermal characteristics that produce offspring of the rare sex. To test this hypothesis, we seeded three secure outdoor ponds with different sex ratios (~M:F 3:1, 1:1, and 1:3) of adult painted turtles (Chrysemys picta), a reptile species with TSD. We then quantified nesting traits that could influence nest temperature and thus offspring sex ratio, including nesting date, nest depth, and nest canopy cover. We found no directional relationship between the ASR treatments and any measured nest traits and thus rejected our hypothesis. Interestingly, increased maternal body size was associated with reduced nest canopy cover, and this trend was more pronounced in the biased ASR treatments. If adaptive sex allocation occurs in this system, it instead may manifest via maternal epigenetic predisposition of offspring sex or in response to a phenomenon other than the ASR. [ABSTRACT FROM AUTHOR]

Turtles are a small clade of vertebrates despite having existed since the Late Triassic. Turtles have a conservative body plan relative to other amniotes, characterized by the presence of a shell and quadrupedality. This morphology is even retained in strong ecological specialists, such as sea turtles, which are secondarily adapted to marine locomotion by strong allometric scaling in their hands. It is possible that the body plan of turtles is strongly influenced by the presence of the shell, acting as a constraint to achieving greater diversity of body forms. Here, we explore the evolutionary allometric relationships of fore‐ and hindlimb stylopodia (i.e., humerus and femur) with one another as well as their relationship with shell size (carapace length) to assess evidence of constraint. All turtles, including Triassic shelled stem turtles, have near‐isometric relationships that do not vary strongly between clades, and evolve at slow evolutionary rates. This indeed indicates that body proportions of turtles are constrained to a narrow range of possibilities. Minor allometric deviations are seen in highly aquatic sea turtles and softshell turtles, which modified their shells by bone losses. Our allometric regressions allow accurate body size estimations for fossils. Several independent sea turtle lineages converged on maximum sizes of 2.2 m of shell length, which may be a biological maximum for the group. [ABSTRACT FROM AUTHOR]

Simple Summary: The rapid development of turtle breeding leads to the risk of aquaculture wastewater pollution. The microalgal strain Desmodesmus sp. CHX1 has shown great potential in removing nutrients from wastewater. This study investigated the effects of temperature and light on the growth of Desmodesmus sp. CHX1 and its nutrient removal in turtle aquaculture wastewater to find the optimal conditions for growth and nutrient removal efficiency. This study was relevant to the development of new strategies for the resource utilization of turtle aquaculture wastewater based on microalgae cultivation. The aim of this study was to explore the effects of temperature and light on microalgal growth and nutrient removal in turtle aquaculture wastewater using a single-factor experiment method. Results showed that the growth process of Desmodesmus sp. CHX1 in turtle aquaculture wastewater exhibited three stages, namely adaptation, logarithmic, and stable periods. Temperature and light significantly influenced the growth and protein and lipid accumulation of Desmodesmus sp. CHX1. The optimal conditions for the growth and biomass accumulation of Desmodesmus sp. CHX1 included a temperature of 30 °C, a photoperiod of 24L:0D, and a light intensity of 180 μmol photon/(m2·s). Increased temperature, photoperiod, and light intensity enhanced nutrient removal efficiency. Maximum nitrogen removal was achieved at a temperature of 30 °C, a photoperiod of 24L:0D, and a light intensity of 180 μmol photon/(m2·s), with the removal efficiency of 86.53%, 97.94%, 99.57%, and 99.15% for ammonia, nitrate, nitrite, and total phosphorus (TP), respectively. Temperature did not significantly affect TP removal, but increased photoperiod and light intensity improved the removal efficiency of TP. The development of microalgae biomass as a feed rich in protein and lipids could address feed shortages and meet the nutritional needs of turtles, offering a feasible solution for large-scale production. [ABSTRACT FROM AUTHOR]

Early juvenile loggerhead turtles (Caretta caretta) rely on gelatinous zooplankton, whereas individuals larger than 40 cm curved carapace length are adapted to crush hard-shelled invertebrates. Nevertheless, fish were reported to be the staple food of loggerhead turtles in the western Mediterranean 30 years ago. Here, the temporal consistency of such a fish-based diet of loggerhead turtles is assessed through gut content analysis and stable isotope analysis of samples from the Mediterranean coast of Spain spanning three decades. The gut contents of 134 juvenile loggerhead turtles (curved carapace length range: 27–71 cm) from three different periods (1991, 1999–2008 and 2010–2017) were analyzed, as well as a subsample of the same turtles (n = 10 in each period) for both bulk and compound-specific stable isotope ratios (CSIA-AA). Gut content analysis revealed a decline in the frequency of occurrence and numerical abundance of fish and an increasing contribution of gastropods and bivalves throughout time, although pelagic tunicates were always the most frequently observed prey. The δ15Nbulk of turtle bone also dropped throughout the study period, but the values of the stable isotope ratio of N in phenylalanine (δ15NPhe) indicated that 52.5% of that variability was due to a baseline shift over time. Accordingly, the trophic position estimated from CSIA-AA did not follow the decreasing pattern of δ15Nbulk, but fluctuated throughout time. The overall evidence indicates that fish consumption by loggerhead turtles in the study region declined through time, but the trophic position of loggerhead turtles did not change simultaneously. This is probably because low trophic prey such pelagic tunicates and filter-feeding bivalves and suspension-feeding gastropods were the bulk of the diet during the whole study period and fish played a minor role, even when their frequency of occurrence peaked. Past levels of high fish consumption might be due to high levels of fishery discards, currently declining because of the recent reduction of the fishing fleet. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To compare multiple noninvasive ECG Methods in pond sliders based upon repeatability, ability to recognize standard waveforms, and measurability. METHODS: The study was performed from November 2023 through January 2024. Ten healthy adult pond turtles were enrolled in the study. ECG tracings were obtained using 4 previously reported and 1 novel ECG methodology, using adhesive patches applied to the prehumeral fossae and abdominal scutes. The 50 ECG tracings were blinded by method and turtle, randomized for evaluation by 4 observers, and assessed for quality on a scale from 0 to 3. RESULTS: Interobserver and intraobserver intraclass correlation coefficients for all tracings were 0.84 and 0.97, respectively, indicating an almost perfect agreement. The average score amongst the observers for each tracing was then averaged by method, ranging from 0.875 to 2.15. The novel method demonstrated a collective average of 2.15 and was the highest scoring method for 8 of 10 turtles. CONCLUSIONS: Electrocardiogram utilizing Methods that apply adhesive patches to the prehumeral fossae and either the abdominal scutes of the plastron or prefemoral fossae in pond turtles can be performed to produce recognizable waveforms. CLINICAL RELEVANCE: Diagnostic tools, such as ECGs, are imperative to enhance veterinary care in nonconventional species, particularly with the rising trend of exotic pets worldwide. [ABSTRACT FROM AUTHOR]

Fences disturb the movements of terrestrial species, altering migration patterns, limiting access to vital resources, and reducing genetic diversity. With almost 40% of the Earth's land surface converted for agriculture, farm fencing to protect crops and corral livestock is expected to stretch into the millions of kilometers. As semi‐terrestrial ectotherms, freshwater turtles are threatened by fences that limit access to resources and increase risks of desiccation, entanglement, and overheating, often resulting in death. To determine the effect of fences, we quantified the movement patterns for a population of eastern long‐necked turtles (Chelodina longicollis) inhabiting an agricultural landscape near Armidale, New South Wales, Australia from November 2022 to September 2023. There was considerable variation in the distance traveled, home range size, and movement corridor selection between turtles that was not explained by the morphological factors of size, mass, or the loss of a limb (likely due to predation attempts). On average, 38% ± 4.70 (x¯ $\bar{x}$ ± SE) of turtle movements were terrestrial (overland) during their active season (spring and summer) during which they encountered fences frequently because of a complex matrix of paddocks. Fence design dictated the distance turtles traveled to locate a suitable passage point. The majority of fences allowed turtles to pass (turtle‐friendly fences, 71.4% of total fence distance) as opposed to turtle‐unfriendly fences (28.6% of total fence distance). Turtles were required to travel almost 4 times the distance to locate a suitable crossing point (a gap or fault in the fence) when they encountered an unfriendly fence (85.32 m ± 29.81) compared to a turtle‐friendly fence (25.85 m ± 3.58). Our results highlight the need for land managers to avoid small‐diameter exclusion fencing and fence designs containing chicken wire that extend to or below ground level. In settings where small‐diameter wire fencing is required, we recommend the installation of turtle gates for small terrestrial fauna or elevating bottom wires at least 50 mm above ground level to facilitate fence permeability. [ABSTRACT FROM AUTHOR]

Background/Objectives: Marine turtles are globally threatened and face daily anthropogenic threats, including pollution. Water pollution from emerging contaminants such as antimicrobials is a major and current environmental concern. Methods: This study investigated the phenotypic antimicrobial resistance and heavy metal resistance genes of 47 Vibrio isolates from different stages of sea turtles (oceanic stage vs neritic stage) from the Taiwanese coast. Results: The results show that a high proportion (48.9%; 23/47) of the Vibrio species isolated from sea turtles in our study had a multiple antimicrobial resistance (MAR) pattern. It was found that Vibrio spp. isolates with a MAR pattern and those with a MAR index value greater than 0.2 were both more likely to be observed in neritic-stage sea turtles. Furthermore, isolates from neritic-stage sea turtles exhibited greater resistance to the majority of antimicrobials tested (with the exception of beta-lactams and macrolides) than isolates from the oceanic-stage groups. Isolates from neritic sea turtles were found to be more resistant to nitrofurans and aminoglycosides than isolates from oceanic sea turtles. Furthermore, isolates with a MAR pattern (p = 0.010) and those with a MAR index value greater than 0.2 (p = 0.027) were both found to be significantly positively associated with the mercury reductase (merA) gene. Conclusions: The findings of our study indicate that co-selection of heavy metals and antimicrobial resistance may occur in aquatic bacteria in the coastal foraging habitats of sea turtles in Taiwan. [ABSTRACT FROM AUTHOR]

Simple Summary: Sea turtles are vital components of marine ecosystems, and their conservation has become a global concern due to declining populations. Monitoring the health of sea turtles is essential for their management, and blood biochemical parameters are increasingly being used as a tool to assess their physiological state. These parameters provide crucial information on metabolic, nutritional, and immune statuses, which are integral to understanding the health, reproductive condition, and stress levels of these animals. The aim of this study was to assess blood biochemical parameters at various ages and during the reproductive and non-reproductive period of Caretta caretta sea turtles, the only known species nesting on the Mediterranean coast. Eighteen biochemical blood parameters were analyzed on sixty-seven subjects. The glucose and total protein values showed significant differences between juveniles, sub-adults, and adults. Despite the small number of subjects, it would seem that, in adult turtles, the values of ALP, γ-GT, Fe, and LDH are higher during the reproductive season. These results made it possible to take a snapshot of the values of the most common biochemical parameters, highlighting the importance of monitoring these to assess the health status and physiological period of Caretta caretta turtles. The Caretta caretta is the only known sea turtle that nests along the coasts of the Mediterranean Sea. It is considered a vulnerable species by the International Union for Conservation of Nature (IUCN) because it is threatened by human activities. The aim of this work was to analyze biochemical parameters in different age groups of C. caretta subjects recovered at the Centro di Referenza Nazionale sul Benessere, Monitoraggio e Diagnostica delle Malattie delle Tartarughe Marine (C.Re.Ta.M.), Sicily. Biometric parameters were recorded for each subject. Peripheral blood was collected and centrifuged, and 18 biochemical parameters were analyzed. Glucose and total proteins showed lower values in juvenile turtles than in sub-adult and adult subjects. Since blood biochemical parameters can be influenced by several factors (age, sex, infectious disease, or trauma), we evaluated differences in the values of some parameters between the reproductive and non-reproductive seasons of adult turtles whose sex and cause of stranding could be determined. Despite the small number of subjects, it would seem that, in adult turtles, the values of ALP, γ-GT, Fe, and LDH are higher during the reproductive season. These biochemical variations showed important differences in the parameters, underlining their importance in assessing the health status of turtles and better understanding their physiology during different stages of their lives. [ABSTRACT FROM AUTHOR]

Cyanobacteria are known for forming associations with various animals, including sea turtles, yet our understanding of cyanobacteria associated with sea turtles remains limited. This study aims to address this knowledge gap by investigating the diversity of cyanobacteria in biofilm samples from loggerhead sea turtle carapaces, utilizing a 16S rRNA gene amplicon sequencing approach. The predominant cyanobacterial order identified was Nodosilineales, with the genus Rhodoploca having the highest relative abundance. Our results suggest that cyanobacterial communities become more diverse as sea turtles age, as we observed a positive correlation between community diversity and the length of a sea turtle's carapace. Since larger and older turtles predominantly utilize neritic habitats, the shift to a more diverse cyanobacterial community aligned with a change in loggerhead habitat. Our research provides detailed insights into the cyanobacterial communities associated with loggerhead sea turtles, establishing a foundation for future studies delving into this fascinating ecological relationship and its potential implications for sea turtle conservation. [ABSTRACT FROM AUTHOR]

Nanhsiungchelys (Testudines: Nanhsiungchelyidae) has been established in the 1960s, but its plastral morphology is not well understood. Here, we report an anterior lobe of the plastron of Nanhsiungchelys from the Upper Cretaceous of Ganzhou Basin, China. The plastron of the new specimen bears a V-shaped notch anteriorly which is absent or unknown in other Nanhsiungchelyidae. Besides, we also further describe the plastron of the holotype of Nanhsiungchelys yangi. These two specimens reveal that the plastron of Nanhsiungchelys spp. is partly hollow, and may have additional ossifications of the epiplastra. All of these suggest an unusual plastral morphology and evolution of Nanhsiungchelys. [ABSTRACT FROM AUTHOR]

Animals that hatch within a subterranean nest, such as turtle hatchlings, expend some of their limited energy reserves digging out through sand or soil to reach the surface. In sea turtles, this emergence process can take the hatchlings 3–7 days. However, we have a poor understanding of this process as it is difficult to observe what is occurring underground. Here, we utilize a novel method to characterize digging-out behaviour: affixing an accelerometer directly to newly hatched green turtles (Chelonia mydas) to record movement until nest emergence. Our data revealed that buried hatchlings maintained a head-up orientation but did not move in the expected left and right swaying motion associated with alternating limb crawling. Rather, they moved using dorsal–ventral heaving and pitching as if swimming vertically through the sand to the surface. Movement activity was irregular and brief, interspersed by many short periods of inactivity, mostly lasting less than 10 min. The first 24 h of head-up activity displayed no diel patterns, but the last 24 h prior to emergence involved more intense movement during night-time hours compared with daytime hours. Thus, our results add valuable new insight, and in some cases change previous assumptions, regarding the digging behaviours during the egg-to-emergence life stage in sea turtles. [ABSTRACT FROM AUTHOR]

Invasive species are one of the leading causes of biodiversity loss. During demographic monitoring of native turtle species in northeast Spain, we captured several alien species of semi-aquatic turtles, including Mauremys mutica. Among them, four individuals of this latter species showed external characteristics that were not fully consistent with the diagnosis of this species. These individuals showed a smaller postocular stripe and 2-3 lateral cervical lines and the typical plastral pattern observed in Mauremys leprosa. The analysis of mitochondrial DNA indicated that the maternal lineage was unequivocally M. mutica (pure or hybrid), but nuclear DNA revealed a heterozygote position at the C-mos gene, matching sequences for this gene in GenBank from both M. leprosa and M. mutica. These results highlight the negative impact of alien turtles, which can genetically contaminate vulnerable native turtle populations. [ABSTRACT FROM AUTHOR]

Hatching synchronisation is widespread in oviparous taxa. It has been demonstrated that many species use sounds to coordinate synchronous hatching, being widespread among archosaurs (birds and crocodilians). Recent studies have shown that some turtle species produce vocalisations from within the egg, but the role of this behaviour in synchronising hatch is untested. The small amount of information about sound production by turtle embryos, limited to a handful of closely related species, precludes any inferences based on differences in their ecology, reproductive behaviour and phylogenetic context. With the goal to investigate if coordinated synchronous behaviour is mediated by within‐egg vocalisations in turtles, we recorded clutches from six different turtle species. The selected animals present different ecological and reproductive niches and belong to distinct phylogenetic lineages at the family level. We aimed to understand: (1) what is the phylogenetic distribution of within‐egg vocal behaviour among turtles; (2) if asynchronous turtle species vocalise from within the egg; (3) if clutch size influences synchronous behaviour and (4) if within‐egg turtle calls follow any phylogenetic signal. The new evidence provides light to the current knowledge about synchronous behaviour and within‐egg calls, challenging previous hypothesis that within‐egg sounds are accidentally produced as side‐effects of other behaviours. [ABSTRACT FROM AUTHOR]

This study introduces new discoveries of fossil footprints from the Middle Jurassic Yaopo Formation in Beijing, China, marking the first reptile fossils that have been discovered in this formation. The two small footprints with parallel digits and drag marks suggest they were made by tetrapods moving through water. While there are similarities to crocodylian and pterosaur tracks, the evaluation suggests that turtles are the most likely trace-makers. If correct, the Yaopo Formation footprints are likely made by xinjiangchelyids, given their dominance in Asian freshwater ecosystems during the Late Jurassic and their widespread distribution in Late Jurassic China. Sichuanchelyids, Bashuchelyidae, and Hongkongochelys are less likely candidates due to their limited temporal and geographical distribution. This finding adds to the growing body of evidence on the evolution and ecology of turtles in Asia during the Late Jurassic period. These new findings offer important insights into the behaviour and spatiotemporal occurrence of these ancient reptiles and expand our understanding of their role in prehistoric aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Illegal poaching and overexploitation for the international pet trade are among the greatest threats to freshwater turtles in Southeast Asia. Expanding consumer research in China is crucial to filling knowledge gaps about the scale and structure of illegal trade and developing audience‐targeted and relevant interventions that may reduce demand for illegal turtles as pets. We applied mixed methods to provide a detailed understanding of the consumer side of the illegal pet turtle trade in China. We conducted 30 interviews with key stakeholders and online surveys (n = 2456) of turtle keepers via community forums. From these, we identified 3 core consumer groups based on their prior turtle‐keeping experience, species exposure, and potential for future purchases. We conducted a thematic qualitative analysis of concepts related to the capability, opportunity, motivation, and behavior (COM‐B) model to determine the factors influencing the illegal pet turtle trade and to identify barriers to illegal purchases. Specifically, we identified purchasers' capabilities, opportunities, and motivations in the context of legality, enforcement risk, captive breeding, and impacts on wild population. We developed consumer journey maps (i.e., visual representations of customer's experiences throughout their buying journey) for core consumer groups. These maps illustrate the sequential behaviors and processes that consumers undertake when purchasing turtles, from initial exposure to sourcing, keeping, and providing a new home. Key factors influencing illegal purchases included convenient purchase channels, misguided cognition and motivations for pet keeping, and weak law enforcement. Effective interventions included messages focusing on shifting cognition and beliefs, increasing legal risk perception, and emphasizing stringent law enforcement, primarily delivered through online channels. Our results underscore the necessity for adaptable, audience‐tailored interventions to reduce consumer demand for illegal wildlife products. The mixed‐methods approach, combining quantitative and qualitative data, provided a comprehensive understanding of the target behavior and can inform the development of effective intervention strategies. [ABSTRACT FROM AUTHOR]

Turtles and tortoises (Order Testudines) are facing an extinction crisis, and ecosystems are at risk of collapsing with the loss of key roles they play. Hatching failure is a crucial barrier to population growth and persistence, but its causes are poorly understood, and it is unknown whether fertilization rates are declining as many populations become smaller and more female‐biased. Here, we show that very few studies of turtle and tortoise hatching success consider fertilization rates, and those that do use unreliable methods to determine egg fertility. We also show that studies of hatching success are biased towards marine turtles, as opposed to freshwater and terrestrial species, and wild rather than captive populations. To address the lack of reliable methods for assessing fertilization rates in turtles and tortoises, a microscopy‐based method (originally designed for bird eggs) for detecting perivitelline membrane (PVM) bound sperm and embryonic nuclei in the germinal disc of unhatched eggs has been developed and tested (in turtle and tortoise eggs). We demonstrate that this method provides unequivocal evidence of egg fertilization in five different turtle and tortoise species from both captive and wild populations, even after eggs have been left in wild nests for the full incubation period. This methodological approach represents a valuable tool for monitoring egg fertility and embryo survival rates in turtles and tortoises, with the potential to provide important insights into the underlying drivers of reproductive failure in threatened captive and wild populations. [ABSTRACT FROM AUTHOR]

Freshwater turtles are often used as terrarium pets, especially juveniles of exotic species. At the adult stage they are often released by their owners into the wild despite their high invasion potential. In Europe these thermophilic potentially invasive alien species occupy the habitats of the native European pond turtle Emys orbicularis (Linnaeus, 1758), with new records from the wild being made specifically in Eastern Europe (Latvia and Ukraine) during recent decades. Assessing the potential of alien freshwater turtles to establish in new territories is of great concern for preventing invasion risks while preserving native biodiversity in the present context of climate change. We explored this issue by identifying the present and future (by 2050) suitable habitats of the European pond turtle and several potentially invasive alien species of freshwater turtle already settled in Europe, using a geographic information system (GIS) modelling approach based on datasets from CliMond for climate, Near-global environmental information (NGEI) for freshwater ecosystems (EarthEnv) and Maxent modelling using open-access databases, data from the literature and original field data. Modelling was performed for seven species of alien freshwater turtles occurring from the extreme northern to southern borders of the European range of E. orbicularis: the pond slider Trachemys scripta (Thunberg and Schoepff, 1792), the river cooter Pseudemys concinna (Le Conte, 1830), the Florida red-bellied cooter Pseudemys nelsoni (Carr, 1938), the false map turtle Graptemys pseudogeographica (Gray, 1831), the Chinese softshell turtle Pelodiscus sinensis (Wiegmann, 1835), the Caspian turtle Mauremys caspica (Gmelin, 1774) and the Balkan terrapin Mauremys rivulata (Valenciennes, 1833). In Ukraine, the most Eastern limit of E. orbicularis distribution, were previously reported northern American originated T. scripta, M. rivulata, M. caspica, whereas in Latvia, Emys' most northern limit, were additionally reported P. concinna, P. nelsoni, G. pseudogeographica and Asia originated P. sinensis. The resulting Species Distribution Models (SDM) were of excellent performance (AUC > 0.8). Of these alien species, the most potentially successful in terms of range expansion throughout Europe were T. scripta (34.3% of potential range expansion), G. pseudogeographica (24.1%), and M. caspica (8.9%) and M. rivulata (4.3%) mainly in Eastern Europe, especially in the south of Ukraine (Odesa, Kherson, Zaporizhzhia regions, and Crimean Peninsula). Correlation between the built SDMs for the native E. orbicularis and the invasive alien T. scripta was reliably high, confirming the highly likely competition between these two species in places they cooccur. Moreover, a Multiple Regression Analysis revealed that by 2050, in most of Europe (from the western countries to Ukraine), the territory overlap between E. orbicularis and potentially invasive alien species of freshwater turtles will increase by 1.2 times, confirming higher competition in the future. Importantly, by 2050, Eastern Europe and Ukraine are predicted to be the areas with most suitable habitats for the European pond turtle yet with most limited overlap with the invasive alien species. We conclude that Eastern Europe and Ukraine are the most relevant priority conservation areas for the European pond turtle where it is now necessary to take protective measures to ensure safe habitat for this native species on the long-term. [ABSTRACT FROM AUTHOR]

The improvement of techniques and analyses to understand the movement of freshwater turtles has helped managers in decision-making and the establishment of management strategies for these animals, which suffer numerous threats. We analyzed the available scientific literature on the use of telemetry in the study of the movement ecology of freshwater turtles, seeking to assess the most commonly used approaches. To this end, we carried out a systematic review of articles published until December 2022 using the PRISMA protocol. We found 104 articles published between 1980 and 2022, with a clear increase in the number of publications in later years. We found publications in 40 journals with 295 authors, 150 institutions and 261 keywords. Three countries had major contributions, and we found studies with 50 species, the most recurrent being Emydoidea blandingii and Glyptemys insculpta. The most commonly used technique to study turtle movement was radiotelemetry. The use of Minimum Convex Polygon – MCP and Kernel Density Estimation – KDE was present in 56% of the studies in the last 10 years, and the evaluation of the home range of the species was the most recurrent type of study. The studies covered 33 freshwater ecoregions, and although most studies were carried out in anthropized areas, covering only 16.2% of all endangered freshwater turtle species and 11.4% of all threatened by international trade, the conservation approach has been increasingly recurrent. Our results highlight trends and gaps in the study of the ecology of freshwater turtle movements and highlight the importance of telemetry as an essential tool for species conservation. Highlights: This study reviews 104 articles on telemetry in aquatic turtles, highlighting the predominant use of radiotelemetry. It reveals a focus on anthropized areas and significant gaps, with only 16.2% of endangered species studied. The research underlines the importance of telemetry in turtle ecology conservation. Conservation efforts are growing, despite existing gaps." [ABSTRACT FROM AUTHOR]

Species of Trypanosoma infecting reptiles are poorly understood and understudied. The study of trypanosomes infecting turtles could lead to a greater understanding of the genus and its evolutionary history. The present study re-evaluates and classifies two previously described species of Trypanosoma in freshwater pelomedusid turtles, Trypanosoma (Haematomonas) neitzi and Trypanosoma (Haematomonas) sheppardi , and characterizes a new species, Trypanosoma (Haematomonas) pienaari , using morphological and molecular data. This study provides the first morphological descriptions and molecular data of South African turtle trypanosomes, setting a base for future research of the reptile trypanosomes of Africa. [ABSTRACT FROM AUTHOR]

The evolution of large size in vertebrates is a fascinating research topic, relevant, for example, for the Cretaceous turtles of the Protostegidae clade, which includes some of the largest turtles to have ever inhabited the Earth. However, there is still limited understanding regarding when and under what conditions large size emerged in this group. Here we describe several limb bones and fossil shell remains from the upper Valanginian, Rosa Blanca Formation of Colombia that, together, shed light on the onset conditions and characteristics of large-size evolution in protostegids. The material, although fragmentary, preserves enough features, such as the sigmoidal curvature of the shaft of the humeri in anterior view and their strong waist, to be attributed to Protostegidae. The fossil turtles described here constitute the largest ever known for the Early Cretaceous worldwide and the oldest record for their group. The ecological and climatic conditions of northern South America during the Late Valanginian are discussed as potential triggers of the emergence of large body size in protostegid turtles. [ABSTRACT FROM AUTHOR]

Sympatric species are expected to differ in resource use in order to avoid competition, leading to niche partitioning in natural communities. Invasive species can disrupt community structure, but these impacts are often difficult to measure. In this study, we used stable isotope analysis of carbon and nitrogen to investigate dietary niche partitioning of freshwater turtle assemblages at three sites in the Middle Rio Grande Basin of New Mexico. We sampled four turtle species common to the region, including Painted Turtles (Chrysemys picta), Spiny Softshells (Apalone spinifera), Common Snapping Turtles (Chelydra serpentina), and invasive Red-Eared Sliders (Trachemys scripta elegans). We found that species composition at the study site with the most anthropogenic influence, the Rio Grande Nature Center in the urban population center of Albuquerque, was dominated by invasive T. s. elegans, while study sites in more remote areas (Sevilleta and Bosque del Apache National Wildlife Refuges) primarily consisted of native species. Furthermore, we observed high overlap in niche space among turtle species at the Rio Grande Nature Center, but evidence consistent with niche partitioning at the other two sites. We found higher nitrogen levels in the more carnivorous A. spinifera and C. serpentina compared to other species. We also found evidence for an ontogenetic shift toward a less carnivorous diet in T. s. elegans. Our study provides valuable baseline information about understudied turtle assemblages within the Middle Rio Grande region and suggests there is potential for competition between invasive T. s. elegans and native turtle species in New Mexico. [ABSTRACT FROM AUTHOR]

Despite suffering dramatic declines due to habitat loss and overexploitation, tortoises and freshwater turtles in Southeast Asia remain understudied. Sustainable forest management offers a promising approach for advancing the conservation of threatened turtle populations. This study examines the effect of reduced impact logging (RIL), a sustainable forestry method, on 2 freshwater turtle species. We examined detectability patterns and habitat relationships for the threatened Malayan flat‐shelled turtle (Notochelys platynota) and the non‐threatened Malayan soft‐shelled turtle (Dogania subplana) in 8 streams within a commercial forest reserve between March and July 2019, in Sabah, Malaysian Borneo. Using single‐species occupancy models, we identified covariates associated with the detection and occupancy probabilities of these species across a post‐harvest recovery gradient (1–21 years since logging). Covariates used in the models were obtained directly from the field or from open‐source remote sensing data. Results for soft‐shelled turtles were inconclusive. In contrast, we found a negative association between monthly rainfall and flat‐shelled turtle detectability. The occupancy probability of flat‐shelled turtles was positively associated with greater distance from logging roads and higher stream flow accumulation. Occupancy probability for flat‐shelled turtles and soft‐shelled turtles was relatively high throughout the reserve (0.79 ± 0.1 [SD] and 0.57 ± 0.22, respectively). These results, suggest that appropriately managed forests, could serve as invaluable conservation areas for imperiled freshwater turtle species in the region. [ABSTRACT FROM AUTHOR]

How often males and females need to mate to maximize their fitness is a source of sexual conflict in animals. Sexual conflict over mating frequency can lead to antagonistic coevolution in which males employ tactics to coerce females into mating, while females resist or evade mating attempts by males. Here, we report on a novel burying behavior observed in female northern map turtles (Graptemys geographica) in Opinicon Lake, Ontario, Canada that appears to function as a tactic to avoid male detection during the mating season. Underwater videos indicated that females are heavily solicited during the mating season with over half the females being actively pursued by males. Biologgers indicated that females are less active and remain deeper than males during the mating season. Our data strongly suggest that female northern map turtles avoid intense solicitation and potential harassment by males by burying themselves in lake sediments. This behavior appears to be a low‐cost solution for females to reduce the costs of resistance and mating while they are constrained to habitats with high male densities for overwintering. [ABSTRACT FROM AUTHOR]

Conservation decisions are often based on population models that rely on underlying assumptions made about species' demographic parameters. The Rio Grande Cooter (Pseudemys gorzugi) is a conservation-dependent riverine turtle, but our understanding of its population dynamics has been limited due to the absence of long-term surveys. We used mark-recapture data collected between 2016 and 2022 from the Black River, New Mexico, USA, to evaluate P. gorzugi somatic growth parameters. Females reached larger maximum size than males but exhibited a slower growth rate. We observed only a slight difference in maximum length and Brody growth coefficient of turtles from different locations, but the growth coefficients were overall significantly lower than any other Pseudemys species. Turtles on the Black River represent the northernmost robust population of P. gorzugi. In light of the intense human use of the river and riparian areas coupled with the impacts of climate change, it is imperative to maintain commitment to conservation efforts to resist population declines given the slow somatic growth rate of the population. [ABSTRACT FROM AUTHOR]

Four wild chelonians (two three-toed box turtles [Terrapene triunguis] and two red-eared sliders [Trachemys scripta elegans]) were presented to an academic wildlife rehabilitation center after presumably being hit by a car. Physical examinations revealed various carapace, bridge, and plastron fractures, as well as a lack of motor function of different limbs. A craniodorsal-caudoventral oblique view or caudodorsal-cranioventral oblique radiographic view made at 45° to the frontal plane (Cr45D-CdV and Cd45D-CrV oblique views, respectively), along with standard views (i.e., dorsoventral, right lateral, craniocaudal views), were performed. The oblique views allowed for visualization of different pectoral girdle or pelvic girdle fractures that were not visualized or clearly identified on the standard views. Based on the four clinical cases described here, the addition of Cr45D-CdV or Cd45D-CrV oblique views to the standard views may be beneficial, especially when advance imaging such as computed tomography is not available. These oblique views can be used to better assess chelonian pectoral and pelvic girdles because these structures are superimposed in standard radiographs. Future studies investigating the diagnostic accuracy of detecting pelvic and pectoral girdle fractures using these views are warranted. [ABSTRACT FROM AUTHOR]

N-acetyl-beta-d-glucosaminidase (NAG) is a lysosomal enzyme found in renal tubular epithelial cells, the concentration of which can be measured in blood as a possible diagnostic tool to monitor renal disease; however, no reference values are currently available in reptiles. This study investigated the presence of plasma NAG concentrations in three reptile species. Blood samples were obtained from clinically healthy bearded dragons (Pogona vitticeps; n = 13), corn snakes (Pantherophis guttatus; n = 9) and wood turtles (Glyptemys insculpta; n = 13). To assess renal health further, a biochemistry panel was performed for all animals, and renal biopsies were collected from the bearded dragons and snakes, but not from the turtles. Biopsies were not taken from wood turtles to limit the risk associated with anesthetizing an endangered species. Of the 35 animals sampled, 29 were considered healthy and included in the study. Plasma NAG concentrations in the wood turtles were significantly lower than in the corn snakes (P = 0.004) and plasma NAG concentrations in the corn snakes were significantly higher than in bearded dragons (P = 0.038). Wood turtles had the lowest NAG concentrations, followed by bearded dragons and corn snakes. In conclusion, NAG reference intervals should be established for each reptile species, and analyte validation is needed for this assay in reptiles. Further research is needed to establish NAG reliability as a diagnostic tool in reptiles. [ABSTRACT FROM AUTHOR]

Coastal habitats are some of the most imperiled due to climate change and anthropogenic activities. As such, it is important to understand population dynamics of the species that may play a role in regulating coastal systems. Diamondback terrapins in Northwest Florida have been understudied, which has resulted in a gap in our knowledge for this region. To help fill this gap, we conducted a capture-mark-recapture study in St. Joseph Bay, Florida, from 2018 to 2021. Overall, we captured 518 individuals, including 146 recaptures, and we used several modeling frameworks to estimate apparent survival, recapture probability, population entrance, and population size. Our estimates of apparent survival were relatively low, especially for adult males (0.77) and adult females (0.83), but there is a considerable amount of uncertainty around our estimates. Our models indicated that the super-population consists of 1122 individuals (971–1327 95% CI), and the population is comprised of more adult males (753; 665–866 95% CI) than adult females (102; 85–130 95% CI) and juveniles (267; 221–331 95% CI). Estimates of population entrance varied by year throughout our study duration. This study is the first to document a Malaclemys terrapin population in this region of Florida, and we recommend long-term monitoring in order to gain inferences for the management of this declining coastal species. [ABSTRACT FROM AUTHOR]

The razor-backed musk turtle (Sternotherus carinatus) is native to the Southwestern United States and is traded as a pet. Currently, turtle species that are traded as pets have been observed in the wild with increasing frequency, and S. carinatus is among them. To effectively manage an invasive species, it is necessary to know its distribution. Therefore, in this study, we report a new observation of S. carinatus. We captured the turtle in a reservoir in Gwangju, South Korea, and confirmed it to be S. carinatus through morphological characteristics and genetic analysis. Our results show that, despite extensive efforts in the management of invasive species, species traded as pets continue to be observed in the wild. [ABSTRACT FROM AUTHOR]

Invasive species are a growing global concern. Modern transportation and the pet trade are facilitating the spread of invasive species. In particular, the global trade of freshwater turtles remains prevalent, with a significant emphasis on their utilization as pets. Aligning with other parts of the world, many recent studies reported a number of alien turtle species in the wild in Korea. However, knowledge of their local establishment and natural breeding is still very limited. In the current study, we report the first natural breeding of Mauremys sinensis in the wild in South Korea. The external features of the observed individual and egg characteristics confirmed its identification. The individual took around 70 minutes to build the nest, lay eggs, and cover up the nest with the soil that it dug from the nest. We recorded a clutch size of ten eggs. The rigid-shelled eggs had an average elongation of 1.82 mm, smaller than M. reevesii. Thus, we confirm the natural breeding and local establishment of M. sinensis in South Korea. Considering previous reports, this finding is significant for understanding both potential competition and putative hybridization with the native species, especially M. reevesii, the endangered native freshwater turtle species in Korea. [ABSTRACT FROM AUTHOR]

Turtle species in the Family Podocnemididae, including the Colombian endemic and critically endangered Magdalena River Turtle Podocnemis lewyana, characteristically present low recapture rates that preclude estimation of population parameters using maximum likelihood modeling. In our 12-year monitoring project with this species, we evaluated changes in relative abundances, proportions of sex/size classes, and individual body sizes and body conditions in a population in four channels in the middle Magdalena River drainage. We also inspected for associations between trends in changes in these variables and differences in hunting pressure and habitat degradation. To inspect for temporal and spatial demographic dynamics, we estimated variation in relative abundances using the Catch Per Unit Effort index, the total number of turtles captured over an entire 5-day sampling period using ten baited funnel traps. Relative abundances and the proportions of sex/size classes were different between sites and years. We found a significant decline in the proportion of females and juveniles over time, along with evidence that the females still present were smaller in body size. Our results support the hypothesis that hunting eliminates adult females from these sites, perhaps also translating into a reduction in recruitment. The lack of evidence of generalized declines in body condition of all size classes suggests that habitat degradation might contribute less to the population declines in this region. Our results also illustrate that even when recapture rates are low, monitoring turtles via standardized trapping may yield insights into the population's conservation status that other relative abundance indices cannot. [ABSTRACT FROM AUTHOR]

The current study examines the growth pattern and lifestyle habits of the freshwater snapping turtles Chelydra and Macrochelys based on limb bone histology. Femora, humeri, and tibiae of 25 individuals selected from a range of ontogenetic stages were assessed to determine inter‐element and intraskeletal histological variation. Osteohistological assessment of multiple elements is consistent with overall moderate growth rates as revealed by the dominance of parallel‐fibered bone. However, the growth was cyclical as shown by deposition of multiple lines of arrested growths in the compacta. It appears that the bone tissue of C. serpentina is more variable through ontogeny with intermittent higher growth rates. M. temminckii appears to grow more slowly than C. serpentina possessing compact and thick cortices in accordance with their larger size. Overall, vascularization decreases through ontogeny with humeri and femora being well‐vascularized in both species. Contrarily, epipodials are poorly vascularized, though simple longitudinal and radial canals are present, suggesting differences in growth patterns when compared with associated diaphyseal sections. The tibiae were found to be the least remodeled of the limb bones and therefore better suited for skeletochronology for snapping turtles. Intra‐elementally, femora and humeri preserved higher cortical vascularity ventrally, suggestive of faster relative growth. We hypothesize that the differential growth pattern in limb bones of snapping turtles may relate to differential functional constraints, where forelimbs are operational in swimming while the hindlimbs provide stability. [ABSTRACT FROM AUTHOR]

Background: The popularity of tortoises kept in captivity is increasing and has caused concern regarding the necessity to establish safe and straightforward anaesthesia for those reptiles. Aim: This study aimed to compare four protocols using levobupivacaine in spinal anaesthesia for the blockade of the caudal neuraxis of red-footed tortoises (Chelonoidis carbonarius). Methods: Twenty-four tortoises were randomly assigned into four groups: G1, levobupivacaine 0.75% (1.15 mg kg−1); G2, levobupivacaine 0.37% (1.15 mg kg−1); G3, levobupivacaine 0.75% (2.3 mg kg−1); and G4, levobupivacaine 0.75% (0.1 ml 5 cm−1 of straight carapace length). Tortoises were evaluated for respiratory rate, muscle relaxation, response to hindlimb or tail pinch, and cloacal reflex. Results: A 1.15 mg kg−1 dose of levobupivacaine 0.37% appears adequate for shorter procedures, whereas a 1.15 mg kg−1 dose of levobupivacaine 0.75% should be appropriate for longer procedures in red-footed tortoises. Conclusion: Our results are the first to show the effects of levobupivacaine on spinal anaesthesia in reptiles. Weight-based doses presented more intense and more homogeneous effects than carapace length-based doses in red-footed tortoises. Spinal anaesthesia of red-footed tortoises was safe and effective with any of the weight-based protocols. [ABSTRACT FROM AUTHOR]

This work aims to confirm the presence of freshwater turtles in the Reserva Ecológica Ciudad Universitaria-Costanera Norte, to assess whether there are monthly variations in the relative abundance of any of the observed species and to study their behavior and habitat use. We conducted weekly observations from October 2022 to June 2023 at four sites in the wetland (HI1, HI2, HI3 and HC), between 12:00 and 16:00 h. The observed turtles were identified and categorized based on behavior as resting, displacing and feeding. Variations in relative abundance were analyzed per site using the Kruskal-Wallis test, applying BenjaminiHochberg post-hoc contrasts when differences were found between months. We detected the presence of Phrynops hilarii, Trachemys dorbigni and Hydromedusa tectifera, with P. hilarii being the most abundant and frequent. No significant relative abundance differences were found for P. hilarii between months in HI2 (χ² =13.78; P=0.088) and HI3 (χ² =7.28; P=0.507). However, there was a higher relative abundance in December compared to May (z=-3.17; P.adj=0.028) and April (z=-3.17; P.adj=0.028) in HI1, and in October than November (z=-2.99; P.adj=0.017), December (z=-2.99; P.adj=0.017), January (z=-2.99; P.adj=0.017), February (z=-2.99; P.adj=0.017), March (z=-2.99; P.adj=0.017) and June (z=-2.99; P.adj=0.017) for HC. Resting and displacement behaviors were observed at all four sites, while feeding behavior was only observed in HI2 and HI3. We defined resting areas in HI1 and HC, resting and feeding areas in HI2 and HI3 and transit areas in HI1, HI2 and HI3. We propose management measures to ensure the conservation of turtles in the reserve. [ABSTRACT FROM AUTHOR]

Studying the interactions between prey and predators is crucial for understanding the intricacies of predator-prey dynamics and for formulating effective conservation strategies. Yet there is almost no systematic analysis of pancake tortoise predation, and its consequences on the tortoise populations. Using camera trapping and visual encounter surveys, we recorded the animals visiting the crevices inhabited by pancake tortoises, as well as their surroundings. From our data, we propose which visitors were potential predators, and consider predator impacts on the species. We suggest ten species (21.3%) as potential predators, among the 47 visiting the tortoise crevices between July 2020 and November 2022. We encountered six adult pancake tortoises killed and eaten by unknown predators. Four of six eggs laid by pancake tortoises in May−June 2022 were also depredated. The white-tailed mongoose (Ichneumia albicauda) and the honey badger (Mellivora capensis) were recorded probing rock crevices inhabited by pancake tortoises, with their behaviour suggesting potential predation upon tortoises. We recorded the rock monitor lizard (Varanus albigularis) and common dwarf mongoose (Helogale parvula) digging pancake tortoise nest sites. This study significantly advances our understanding of the predation risk to the critically endangered pancake tortoise. [ABSTRACT FROM AUTHOR]

Simple Summary: Animal personalities could affect the behavior and physiology of both native and invasive species during biological invasion. However, little is known about the personality interaction effects on foraging behavior and growth between native and invasive species. We used the red-eared slider turtle and Chinese pond turtle as models to investigate how personality interactions effect the foraging behavior and growth of both these turtle species. The results showed that the foraging behavior of M. reevesii was mainly affected by the personality of T. scripta elegans. However, the foraging behavior of T. scripta elegans was effected by both their own personality and the personalities of M. reevesii. Additionally, the growth of both M. reevesii and T. scripta elegans were not effected by the personality combinations. The results revealed the mechanisms of personality interaction effects on the foraging behavior and growth of both native and invasive species during biological invasion. This study provides empirical evidence to help understand the effects of personalities on invasion dynamics. Animal personalities play a crucial role in invasion dynamics. During the invasion process, the behavioral strategies of native species vary among personalities, just as the invasive species exhibit variations in behavior strategies across personalities. However, the impact of personality interactions between native species and invasive species on behavior and growth are rarely illustrated. The red-eared slider turtle (Trachemys scripta elegans) is one of the worst invasive species in the world, threatening the ecology and fitness of many freshwater turtles globally. The Chinese pond turtle (Mauremys reevesii) is one of the freshwater turtles most threatened by T. scripta elegans in China. In this study, we used T. scripta elegans and M. reevesii to investigate how the personality combinations of native and invasive turtles would impact the foraging strategy and growth of both species during the invasion process. We found that M. reevesii exhibited bolder and more exploratory personalities than T. scripta elegans. The foraging strategy of M. reevesii was mainly affected by the personality of T. scripta elegans, while the foraging strategy of T. scripta elegans was influenced by both their own personality and personalities of M. reevesii. Additionally, we did not find that the personality combination would affect the growth of either T. scripta elegans or M. reevesii. Differences in foraging strategy may be due to the dominance of invasive species and variations in the superficial exploration and thorough exploitation foraging strategies related to personalities. The lack of difference in growth may be due to the energy allocation trade-offs between personalities or be masked by the slow growth rate of turtles. Overall, our results reveal the mechanisms of personality interaction effects on the short-term foraging strategies of both native and invasive species during the invasion process. They provide empirical evidence to understand the effects of personality on invasion dynamics, which is beneficial for enhancing comprehension understanding of the personality effects on ecological interactions and invasion biology. [ABSTRACT FROM AUTHOR]

Macrochelys temminckii (alligator snapping turtle) is an aquatic turtle endemic to the southeastern United States that was proposed for listing under the Endangered Species Act in 2021. In the present study we analyzed total mercury (THg) concentrations in skeletal muscle, tail clips, and nail tissue of 93 M. temminckii sampled from 14 waterbodies in eastern Texas (USA). Our objectives were to assess (1) the degree of correlation between internal tissue (skeletal muscle and tail clip samples) and keratin (nail samples), (2) the influence of ecological factors (turtle size and waterbody/sampling site) on THg concentrations, and (3) whether THg concentrations were high enough to pose a risk to human consumers. The mean (±SE) THg concentrations of muscle and nail were 1.16 ± 0.08 μg/g dry weight and 4.21 ± 0.24 μg/g dry weight, respectively, and THg concentrations were highly dependent on the sampling site. The THg concentrations of nails were correlated with muscle concentrations (R2 = 0.56, p < 0.001). The effect of body size on THg concentrations varied by sampling site, indicating that size is not a good predictor of Hg concentration across sites. Finally, THg concentrations in M. temminckii of eastern Texas were high enough to pose a potential risk to human health based on US Environmental Protection Agency dietary guidelines. Environ Toxicol Chem 2024;43:1903–1913. © 2024 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

The presence of domestic animals in the wilderness has a negative effect on wildlife populationsor; for instance, in addition to habitat loss, urbanization, and coastal light pollution, sea turtles also suffer from another threat: the predation of their eggs, hatchlings, and even female nesters by domestic, feral, and/or wild animals. Domestic dogs are a considerable concern for turtles in nesting areas, due to their free-ranging lifestyle and the absence of predators. This study sought to evaluate the nest density and rates of sea turtle predation caused mainly by canids: foxes (native predator) and dogs (introduced predator) in the nesting areas of Southern Bahia, Brazil. Predation data was collected during field surveys and by using camera traps and hair traps installed in nests. During the sampling period, an average of 46 nests were laid by three sea turtle species: Caretta caretta, Eretmochelys imbricata, and Lepidochelys olivacea; 46.4% were lost due to predation or inundation caused by the tides. Canine populations on the island have an evident impact on sea turtle nests. Thus, it is crucial to design and implement environmental education programs and management plans with the local community to help reduce human-made and natural loss of nests and safeguard sea turtle populations and their habitat. [ABSTRACT FROM AUTHOR]

Interaction with fishing gears represents the main anthropogenic threat at sea for sea turtles worldwide, and identifying the hotspots of turtle bycatch is a priority knowledge gap.Turtle stranding data represent a source of information about mortality areas at sea that are not fully exploited. This study aims to infer turtle mortality areas of turtles stranded along the Italian Adriatic Coast in the period 2019–2021 (1432 records), through backtrack modelling of carcasses. Specifically, the decomposition process of eight loggerhead carcasses was monitored, and the relationship between floating period (FP), turtle size and sea temperature was modelled through a generalized additive model. Oceanographic information was then used to track the routes of floating carcasses back, knowing their size and decomposition stage, and finally estimate the likely area of mortality. A complementary numerical experiment of connectivity between coastal and offshore areas gave indication that areas of potential mortality are relatively close to the coast, particularly in the northern Adriatic.Stranded turtles probably represent just a small fraction (17%–25%) of total at‐sea mortalities in the study area (Italian Adriatic waters), with decomposition rates, season and distance from shore influencing their stranding likelihood. Hence, strandings can inform only about spatio‐temporal variability of coastal mortality hotspots.Inferred areas of turtle mortality were most likely located in the North and Central Adriatic all over the year and overlap with heatmaps of fishing effort, obtained from vessel monitoring system (VMS) and automatic identification system (AIS) data, in the Gulf of Manfredonia and in the North‐West Adriatic in the cold (September–December) and warm (May–August) periods, respectively. [ABSTRACT FROM AUTHOR]