The role of social media in public health awareness during times of war in Sudan: snakebites and scorpion stings.

BACKGROUND: Snakebite envenomation (SBE) and scorpion sting envenomation (SSE) are significant neglected tropical diseases that primarily affect impoverished communities in rural areas of developing nations. A lack of understanding about snake and scorpion species and their distribution exacerbates the disabilities and fatalities caused by SBE and SSE. In Sudan, particularly in regions affected by ongoing conflicts where healthcare resources are scarce, social media platforms offer a cost-effective approach to addressing public health challenges. Our aim in this study is to highlight the benefits of using social media for data collection and health promotion in such environments. METHODS: We present a cost-effective communication and data collection strategy implemented at the Toxic Organisms Research Centre (TORC) of the University of Khartoum, focusing on a Facebook group, "Scorpions and Snakes of Sudan", as our primary social media platform. Additionally, we discuss the lessons learned and the initial impact of this strategy on enhancing population health literacy. RESULTS: The group community is composed of ~ 5000 members from 14 countries. During the period from January 2023 to January 2024, we received 417 enquiries about snakes and scorpions belonging to 11 families and composed of 55 species. In addition, 53 other enquiries covered a range of organisms and their tracks (e.g., spiders, skinks, chameleons, foxes, sun spiders, centipedes, lizards, moth larvae, and insect tracks). The first photographic evidence of Malpolon monspessulanus in Sudan was via the group activities. The rare species Telescopus gezirae, the Blue Nile cat snake, is also documented via the group member's queries. Recognizing the evolving nature of social media use in public health, we also address the current limitations and evidence gaps that need to be addressed to effectively translate best practices into policy. CONCLUSION: In conclusion, utilizing Facebook as an institutional platform to share scientific information in simple Arabic language underscores the proactive roles that citizens, scientists, and public health stakeholders can play in leveraging social media for eHealth, eAwareness, and public health initiatives. This approach highlights the potential for collaborative efforts, particularly during crises, to maximize the benefits of social media in advancing public health.

Levels of polycyclic aromatic hydrocarbons and organochlorine pesticides in sea snakes (Elapidae: Hydrophiinae) from Sharjah, United Arab Emirates.

This study reports OCP and PAH concentrations in the tissues of stranded sea snakes from Sharjah, UAE. Samples from 10 Hydrophis lapemoides, 2 Hydrophis ornatus and 1 Hydrophis curtus were analyzed. Muscle, liver and fat tissues were extracted using micro-QuEChERs, followed by d-SPE and analyzed using GC/MS. Higher concentrations of OCPs were detected, while PAHs were more frequently detected. Significant correlations suggest that OCPs and PAHs do bioaccumulate in the tissues of sea snakes. Additionally, OCPs with lower log Kow (octanol-water partition coefficient) values were mainly detected in the muscle samples of H. lapemoides, whereas OCPs with higher log Kow values were more commonly present in the liver and fat samples. The concentrations of OCPs reported in this study were higher than those previously documented in other marine reptiles in the UAE or sea snakes from different geographical regions.

Prey specificity of predatory venoms.

Venom represents a key adaptation of many venomous predators, allowing them to immobilise prey quickly through chemical rather than physical warfare. Evolutionary arms races between prey and a predator are believed to be the main factor influencing the potency and composition of predatory venoms. Predators with narrowly restricted diets are expected to evolve specifically potent venom towards their focal prey, with lower efficacy on alternative prey. Here, we evaluate hypotheses on the evolution of prey-specific venom, focusing on the effect of restricted diet, prey defences, and prey resistance. Prey specificity as a potential evolutionary dead end is also discussed. We then provide an overview of the current knowledge on venom prey specificity, with emphasis on snakes, cone snails, and spiders. As the current evidence for venom prey specificity is still quite limited, we also overview the best approaches and methods for its investigation and provide a brief summary of potential model groups. Finally, possible applications of prey-specific toxins are discussed.

Local envenoming by the Eastern Montpellier snake, Malpolon insignitus fuscus (Fleischmann, 1831), Psammophiidae, Psammophiinae, and review of the evidence-based medical risks of bites by Malpolon spp.

For more than a century, concerns about the medical significance of Montpellier snakes, Malpolon spp. (Psammophiidae, Psammophiinae) have been expressed by herpetologists and toxinologists. Although some of the opinions have suggested that the most familiar species, the Western Montpellier snake, Malpolon monspessulanus, poses a significant medical risk, only a few detailed, formally documented reports have been published that describe effects in humans. Two reports support a rare risk of systemic envenoming (cranial nerve palsies) after prolonged bites by M. monspessulanus. Relevantly, there has been only one previous report describing a bite by the Eastern Montpellier snake, Malpolon insignitus. Reported here are the effects of a bite inflicted by a 1.1-meter female Malpolon insignitus fuscus in Alborz Province, Iran. The 40-yr-old male victim was handling the snake while preparing to photograph it when he was bitten on the right wrist. The snake remained attached for approximately 40-seconds during which it repeatedly advanced its jaws. The bite caused moderate local envenoming that featured moderate but reportedly notably uncomfortable sharp pain, moderate edema, erythema and pruritis; wound site bleeding was transient and proportional. Full resolution required 5-days; there were no sequelae. The clinical evolution included signs/symptoms consistent with Type I hypersensitivity and subtype Type IV hypersensitivity. Detailed reports of medically significant bites by Malpolon spp. are briefly reviewed and the evidence for medical significance of the genus is evaluated. Management of envenoming by Malpolon spp. is supportive only; almost all victims with qualified medical review have developed only local envenoming that is often mild-moderate. Notably rare systemic effects, e.g., neurotoxicity so far limited to non-progressive cranial nerve palsies, should prompt airway protection, ICU admission, and consultation as indicated. Future study of Malpolon venoms and formal documentation of their bites should increase the evidence quality for the medical risk profile of the genus.

Fossil-informed biogeographic analysis suggests Eurasian regionalization in crown Squamata during the early Jurassic.

Background: Squamata (lizards, snakes, and amphisbaenians) is a Triassic lineage with an extensive and complex biogeographic history, yet no large-scale study has reconstructed the ancestral range of early squamate lineages. The fossil record indicates a broadly Pangaean distribution by the end- Cretaceous, though many lineages (e.g., Paramacellodidae, Mosasauria, Polyglyphanodontia) subsequently went extinct. Thus, the origin and occupancy of extant radiations is unclear and may have been localized within Pangaea to specific plates, with potential regionalization to distinct Laurasian and Gondwanan landmasses during the Mesozoic in some groups. Methods: We used recent tectonic models to code extant and fossil squamate distributions occurring on nine discrete plates for 9,755 species, with Jurassic and Cretaceous fossil constraints from three extinct lineages. We modeled ancestral ranges for crown Squamata from an extant-only molecular phylogeny using a suite of biogeographic models accommodating different evolutionary processes and fossil-based node constraints from known Jurassic and Cretaceous localities. We hypothesized that the best-fit models would not support a full Pangaean distribution (i.e., including all areas) for the origin of crown Squamata, but would instead show regionalization to specific areas within the fragmenting supercontinent, likely in the Northern Hemisphere where most early squamate fossils have been found. Results: Incorporating fossil data reconstructs a localized origin within Pangaea, with early regionalization of extant lineages to Eurasia and Laurasia, while Gondwanan regionalization did not occur until the middle Cretaceous for Alethinophidia, Scolecophidia, and some crown Gekkotan lineages. While the Mesozoic history of extant squamate biogeography can be summarized as a Eurasian origin with dispersal out of Laurasia into Gondwana, their Cenozoic history is complex with multiple events (including secondary and tertiary recolonizations) in several directions. As noted by previous authors, squamates have likely utilized over-land range expansion, land-bridge colonization, and trans-oceanic dispersal. Tropical Gondwana and Eurasia hold more ancient lineages than the Holarctic (Rhineuridae being a major exception), and some asymmetries in colonization (e.g., to North America from Eurasia during the Cenozoic through Beringia) deserve additional study. Future studies that incorporate fossil branches, rather than as node constraints, into the reconstruction can be used to explore this history further.

The Silk roads: phylogeography of Central Asian dice snakes (Serpentes: Natricidae) shaped by rivers in deserts and mountain valleys.

Influenced by rapid changes in climate and landscape features since the Miocene, widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic diversity. The dice snake Natrix tessellata, widely distributed in the Western Palearctic is one such species. We aimed to resolve a detailed phylogeography of N. tessellata with a focus on the Central Asian clade with 4 and the Anatolia clade with 3 mitochondrial lineages, trace their origin, and correlate the environmental changes that affected their distribution through time. The expected time of divergence of both clades began at 3.7 Mya in the Pliocene, reaching lineage differentiation approximately 1 million years later. The genetic diversity in both clades is rich, suggesting different ancestral areas, glacial refugia, demographic changes, and colonization routes. The Caspian lineage is the most widespread lineage in Central Asia, distributed around the Caspian Sea and reaching the foothills of the Hindu Kush Mountains in Afghanistan, and Eastern European lowlands in the west. Its distribution is limited by deserts, mountains, and cold steppe environments. Similarly, Kazakhstan and Uzbekistan lineages followed the Amu Darya and the Syr Darya water systems in Central Asia, with ranges delimited by the large Kyzylkum and Karakum deserts. On the western side, there are several lineages within the Anatolia clade that converged in the central part of the peninsula with 2 being endemic to Western Asia. The distribution of both main clades was affected by expansion from their Pleistocene glacial refugia around the Caspian Sea and in the valleys of Central Asia as well as by environmental changes, mostly through aridification.

Terrestrial wildlife as indicators of microplastic pollution in western Thailand.

Plastic pollution in terrestrial wildlife represents a new conservation challenge, with research in this area, especially within protected areas (PAs), being scant. This study documents the accumulation of microplastics (MPs) in terrestrial wildlife both inside and outside PAs in western Thailand. Carcasses of road-killed vertebrates in good condition, as well as live tadpoles, were collected to examine their exposure to plastic pollution. The digestive tracts of the vertebrate carcasses and the entire bodies of tadpoles were analyzed for MPs, which were identified if they measured over 50 µm. A total of 136 individuals from 48 vertebrate species were examined. The sample comprised snakes (44.12%), birds (11.03%), lizards (5.15%), tadpoles (32.25%), amphibians (5.88%), and mammals (1.47%). In total, 387 MPs were found in 44 species (91.67%), with an average occurrence of 3.25 ± 3.63 MPs per individual or 0.05 ± 0.08 MPs per gram of body weight. The quantities of MPs significantly varied among the animal groups, both in terms of number per individual (p < 0.05) and number per gram of body weight (p < 0.01). Furthermore, a significant difference in MP quantities was observed between specimens collected inside and outside PAs on an individual basis (p < 0.05), but not on a body weight basis (p = 0.07). Most MPs were fibers (77%), followed by fragments (22.22%), with only a minimal presence of film (0.52%) and foam (0.26%). Of all the MPs identified, 36.84% were confirmed as plastics or fibers made from natural materials, and 31.58% were plastics, including Polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), Polyvinylidene chloride (PVDC), and polyester (PES). Additionally, fibers made of cotton, and those containing polyurethane (PU), rayon, PES, and combinations of rayon and PU, were identified. The quantities of MPs were significantly influenced by animal body weight, factors associated with human settlement/activity, and land use types. Our findings highlight the prevalence of plastic pollution in terrestrial vertebrates within Thai PAs. Further toxicological studies are required to establish plastic pollution standards. It is proposed that snakes, obtained from road kills, could serve as a non-invasive method for monitoring plastic pollution, thus acting as an indicator of the pollution threat to species within terrestrial ecosystems. There is an urgent need for the standardization of solid waste management at garbage dump sites in remote areas, especially within PAs. Conservation education focusing on MP occurrence, potential sources, and impacts could enhance awareness, thereby influencing changes in behaviors and attitudes toward plastic waste management at the household level.

Phylogenomic insights into the diversity and evolution of Palearctic vipers.

Despite decades of molecular research, phylogenetic relationships in Palearctic vipers (genus Vipera) still essentially rely on a few loci, such as mitochondrial barcoding genes. Here we examined the diversity and evolution of Vipera with ddRAD-seq data from 33 representative species and subspecies. Phylogenomic analyses of âˆ¼ 1.1 Mb recovered nine major clades corresponding to known species/species complexes which are generally consistent with the mitochondrial phylogeny, albeit with a few deep discrepancies that highlight past hybridization events. The most spectacular case is the Italian-endemic V. walser, which is grouped with the alpine genetic diversity of V. berus in the nuclear tree despite carrying a divergent mitogenome related to the Caucasian V. kaznakovi complex. Clustering analyses of SNPs suggest potential admixture between diverged Iberian taxa (V. aspis zinnikeri and V. seoanei), and confirm that the Anatolian V. pontica corresponds to occasional hybrids between V. (ammodytes) meridionalis and V. kaznakovi. Finally, all analyzed lineages of the V. berus complex (including V. walser and V. barani) form vast areas of admixture and may be delimited as subspecies. Our study sets grounds for future taxonomic and phylogeographic surveys on Palearctic vipers, a group of prime interest for toxinological, ecological, biogeographic and conservation research.

Anticancer potency of Egyptian venom snakes on MCF-7 and HepG2 carcinoma cells.

Breast and hepatic cancers are the leading incidences in the globe occurring of the human sufferings from various cancers. Snake venoms have been reported to provide effective therapeutic agents. The current study investigates the anticancer potency of Egyptian venoms snakes on two cells: breast cancer cells (MCF-7) and hepato-cancer cells (HepG2) (In vitro assay). The examined venoms were more potent on MCF-7 than HepG2 cells. Their inhibition % on MCF-7 ranged from 71.47 to 99.02% with medium inhibition concentrations (IC50s): 3.48, 3.60, 3.70, 4.33, and 4.49 µg/ml for venoms: Echis pyramid (E.H), Cerastes vipera (C.V), Naja haje (N.H), Echis coloratus (E.C), and Cerastes cerastes (C.C), respectively. The values of IC50s on HepG2 were 4.32, 17.77, 59.72, 63.75, and 217.90 µg/ml for toxins: E.C, E.P, C.V, C.C, and N.H, respectively. Some biomarkers were conducted to investigate the apoptotic effects of toxins into the cells. Increasing profiles of lactate dehydrogenase (LDH) activity and levels of glutathione content (GSH) and malodialdhyde (MDA) as well as repairment of DNA indicated such these actions. So, more reliable investigations on these venoms were needed to provide intelligent therapeutic agent for cancer treatment.

The pancreas does not contribute to the non-adrenergic-non-cholinergic stimulation of heart rate in digesting pythons.

Vertebrates elevate heart rate when metabolism increases during digestion. Part of this tachycardia is due to a non-adrenergic-non-cholinergic (NANC) stimulation of the cardiac pacemaker, and it has been suggested these NANC factors are circulating hormones that are released from either gastrointestinal or endocrine glands. The NANC stimulation is particularly pronounced in species with large metabolic responses to digestion, such as reptiles. To investigate the possibility that the pancreas may release hormones that exert positive chronotropic effects on the digesting Burmese python heart, a species with very large postprandial changes in heart rate and oxygen uptake, we evaluate how pancreatectomy affects postprandial heart rate before and after autonomic blockade of the muscarinic and the beta-adrenergic receptors. We also measured the rates of oxygen consumption and evaluated the short-term control of the heart using the spectral analysis of heart rate variability and the baroreflex sequence method. Digestion caused the ubiquitous tachycardia, but the intrinsic heart rate (revealed after the combination of atropine and propranolol) was not affected by pancreatectomy and therefore hormones, such as glucagon and insulin, do not appear to contribute to the regulation of heart rate during digestion in Burmese pythons.

Evaluation of venom diversity and antivenom quality from the venom of long-term captive vs recently wild captured Pseudocerastes persicus snake: An In vitro and In vivo study.

Snakebite envenomation is a life-threatening condition and antivenoms are used as the most effective treatment. Venom obtained from snakes in long-term captivity showed some variations in comparison to the venom of the wild snakes. The objective of this study is to compare the venom of the Pseudocerastes persicus under long-term captivity and wild conditions as well as the antivenom obtained from these venoms. We have analyzed venom samples and produced trivalent antivenoms using the venom of long-term captive (LTC) or recently wild-captured (RWC) Pseudocerastes persicus, and RWC Macrovipera lebetina, and Echis carinatus. The HPLC analysis revealed that the RWC snakes' venom had three peaks that were not present in the LTC snake's venom. Further analysis using MALDI-TOF and MS/MS showed that the fraction with a retention time (RT) of 14 min contained a toxin from the Kunitz-type serine protease inhibitor (KUT) class, while the fraction with RT 21 a peptide identified within the snake venom metalloproteinase (SVMP) class. The third peak was identified as a sphingolipid. Interestingly, the in vivo preclinical tests showed no significant differences in the effectiveness of the antivenoms. which could be due to the cross-immunogenicity or cross-reactivity between different toxins in the venom. According to our results, small variations in the venom composition of a species do not lead to a decrease in the efficacy of the polyvalent antivenom.

On the role of TFEC in reptilian coloration.

Reptilian species, particularly snakes and lizards, are emerging models of animal coloration. Here, I focus on the role of the TFEC transcription factor in snake and lizard coloration based on a study on wild-type and piebald ball pythons. Genomic mapping previously identified a TFEC mutation linked to the piebald ball python phenotype. The association of TFEC with skin coloration was further supported by gene-editing experiments in the brown anole lizard. However, novel histological analyses presented here reveal discrepancies between the ball python and the anole TFEC mutants phenotype, cautioning against broad generalizations. Indeed, both wild-type and piebald ball pythons completely lack iridophores, whereas the TFEC anole lizard mutants lose their iridophores compared to the wild-type anole. Based on these findings, I discuss the potential role of the MiT/TFE family in skin pigmentation across vertebrate lineages and advocate the need for developmental analyses and additional gene-editing experiments to explore the reptilian coloration diversity.

Distinct regulatory networks control toxin gene expression in elapid and viperid snakes.

BACKGROUND: Venom systems are ideal models to study genetic regulatory mechanisms that underpin evolutionary novelty. Snake venom glands are thought to share a common origin, but there are major distinctions between venom toxins from the medically significant snake families Elapidae and Viperidae, and toxin gene regulatory investigations in elapid snakes have been limited. Here, we used high-throughput RNA-sequencing to profile gene expression and microRNAs between active (milked) and resting (unmilked) venom glands in an elapid (Eastern Brown Snake, Pseudonaja textilis), in addition to comparative genomics, to identify cis- and trans-acting regulation of venom production in an elapid in comparison to viperids (Crotalus viridis and C. tigris). RESULTS: Although there is conservation in high-level mechanistic pathways regulating venom production (unfolded protein response, Notch signaling and cholesterol homeostasis), there are differences in the regulation of histone methylation enzymes, transcription factors, and microRNAs in venom glands from these two snake families. Histone methyltransferases and transcription factor (TF) specificity protein 1 (Sp1) were highly upregulated in the milked elapid venom gland in comparison to the viperids, whereas nuclear factor I (NFI) TFs were upregulated after viperid venom milking. Sp1 and NFI cis-regulatory elements were common to toxin gene promoter regions, but many unique elements were also present between elapid and viperid toxins. The presence of Sp1 binding sites across multiple elapid toxin gene promoter regions that have been experimentally determined to regulate expression, in addition to upregulation of Sp1 after venom milking, suggests this transcription factor is involved in elapid toxin expression. microRNA profiles were distinctive between milked and unmilked venom glands for both snake families, and microRNAs were predicted to target a diversity of toxin transcripts in the elapid P. textilis venom gland, but only snake venom metalloproteinase transcripts in the viperid C. viridis venom gland. These results suggest differences in toxin gene posttranscriptional regulation between the elapid P. textilis and viperid C. viridis. CONCLUSIONS: Our comparative transcriptomic and genomic analyses between toxin genes and isoforms in elapid and viperid snakes suggests independent toxin regulation between these two snake families, demonstrating multiple different regulatory mechanisms underpin a venomous phenotype.

Comparative morphology of oral glands in snakes of the family Homalopsidae reveals substantial variation and additional independent origins of salt glands within Serpentes.

Using diffusible iodine-based contrast-enhanced computed tomography (diceCT), we examined the morphology of the oral glands of 12 species of the family Homalopsidae. Snakes of this family exhibit substantial interspecific morphological variation in their oral glands. Particular variables are the venom glands, ranging from large (e.g., Subsessor bocourti) to small (e.g., Erpeton tentaculatum). The supra- and infralabial glands are more uniform in morphology, being the second most developed in almost all the sampled species. Premaxillary glands distinct from the supralabial glands were observed in five species (Myron richardsonii, Bitia hydroides, Cantoria violacea, Fordonia leucobalia, and Gerarda prevostiana), in addition to Cerberus rynchops, the only species in which this condition was previously documented associated with the excretion of salt. In the three species of the saltwater group of homalopsids (C. violacea, F. leucobalia, and G. prevostiana), the premaxillary glands also extend posteriorly, occupying a large area above the supralabial gland, a condition not observed in any other species of snake studied thus far. Character evolution analyses indicate that premaxillary glands differentiated from the supralabial gland and evolved independently three or four times in the family, always in lineages that invaded marine habitats. Our results suggest that the differentiated premaxillary glands are likely salt glands, as is the case in C. rynchops. If corroborated, this increases to six or seven the number of independent evolutionary origins of salt glands in snakes that have undergone an evolutionary transition to marine life.

An extremely rare serovar of Salmonella enterica (Yopougon) discovered in a Western Whip Snake (Hierophis viridiflavus) from Montecristo Island, Italy: case report and review.

Reptiles, including snakes, can be asymptomatically infected with multiple pathogen microorganisms, including Salmonella spp., which is considered an important concern for public and animal health. Small and uninhabited isles are quite ecologically different from mainland and represent interesting fields of study, to discover unexpected biological and microbiological aspects of their wild inhabitants. This work reports the presence of the very rare Salmonella enterica serovar Yopougon, isolated in a carcass of a native wild snake (Hierophis viridiflavus) from an Italian uninhabited island of Mediterranean Sea, Montecristo. To our knowledge, S. enterica serovar Yopougon was previously isolated only once 34 years earlier in Ivory Coast, from a human fecal sample. In the present study, we present the genomic characterization of the new isolate, the phylogenetic comparison with the previously isolated S. enterica serovar Yopougon strain of human origin and with other sequences available in public databases. In addition, an extensive review of available data in the literature and from our case history is provided. Our finding represents an example of the ability of some pathogens to travel for very long distances within their hosts and then to infect others, even from different taxa.

In-depth immunorecognition and neutralization analyses of Micrurus mipartitus and M. dumerilii venoms and toxins by a commercial antivenom.

In Colombia, the Micrurus genus comprises 30 species, including M. mipartitus and M. dumerilii, which are of major clinical relevance due to their wide geographical distribution and the number of snakebites inflicted by them. These neurotoxic envenomations are characterized by neuromuscular paralysis attributed to venom components such as three-finger toxins (3FTx) and phospholipases (PLA2). Additionally, there is limited information available on the neutralizing coverage of commercially available antivenoms, underscoring the need to perform studies to assess the cross-neutralizing ability of these life-saving products. Therefore, we present an in-depth immunorecognition analysis by the anticoral-INS antivenom from Colombia on the M. mipartitus and M. dumerilii venoms. The antivenom cross-recognized the whole venoms and their components with different intensities. For instance, the antivenom showed better recognition on PLA2s than on 3FTxs in both venoms. Moreover, at doses tested, the antivenom totally neutralized the lethal effect of M. dumerilii venom; however, it did not neutralize this effect induced by M. mipartitus venom and its main toxic components from the southwestern region of the department of Antioquia. Furthermore, the anticoral-INS antivenom displayed better cross-immunorecognition of PLA2-predominant Micrurus venoms than of 3FTx-predominant Micrurus venoms. This highlights the need to include venoms from both types of venom patterns in the immunization mixture to produce antivenoms against coral snakes. Finally, our results suggest the need for further research to optimize the composition of immunizing mixtures for antivenom production and improve their efficacy against coral snake envenomation in Colombia and the Americas.

Habituação ou sensibilização? Efeito comportamental em Cascavel sul-americanas (Crotalus durissus)

The defensive behavior represents a crucial strategy for snakes, influenced by intrinsic factors that play significant roles in the survival, reproduction, and evolution of species. The present study focused on the rattlesnake (Crotalus durissus), a species exhibiting a wide variety of defensive behaviors. The research aimed to assess the manifestation of habituation or sensitization in the defensive behavior of rattlesnakes, establishing a comparison between adult and young individuals. For this purpose, 44 snakes (22 juveniles and 22 adults) kept in captivity were subjected to encounters with a white-eared opossum plush model in a controlled arena. Data collection extended over a period of 6 days, during which behaviors were recorded. The statistical analysis employed a mixed-effects generalized linear model (GLMM) with Poisson distribution, using R software (version 3.34). The results revealed an increase in aggression in both adult and juvenile groups on the sixth day. Notably, juveniles exhibited higher responsiveness and aggression compared to adults. This study provided clear evidence of ontogenetic differences in the selection of defensive strategies between juveniles and adults. This distinction was influenced by experience, limitations, and inherent needs at each life stage of the snakes. Contrary to expectations based on the literature, both juvenile and adult groups did not exhibit habituation to the presented stimuli, indicating instead a sensitization phenomenon. These findings emphasize the importance of considering ontogenetic variables when analyzing defensive behavior in snakes, particularly in the context of predator-prey interactions. Furthermore, the results have practical implications, especially in regions where the presence of rattlesnakes may pose risks to the community. This study contributes to a deeper understanding of defensive behavior patterns in rattlesnakes, providing valuable insights for management and conservation strategies in controlled environments.

O comportamento defensivo representa uma estratégia crucial para as serpentes, sendo influenciado por fatores intrínsecos que desempenham papéis significativos na sobrevivência, reprodução e evolução das espécies. O presente estudo concentrou-se na cascavel (Crotalus durissus), uma espécie que exibe uma ampla variedade de comportamentos defensivos. O objetivo da pesquisa consistiu em avaliar a manifestação de habituação ou sensibilização do comportamento defensivo em cascavéis, estabelecendo uma comparação entre indivíduos adultos e jovens. Para tanto, foram empregadas 44 serpentes (22 filhotes e 22 adultos) mantidas em cativeiro, submetidas a confrontos com um modelo de pelúcia de gambá-de-orelha-branca em uma arena controlada. A coleta de dados estendeu-se por um período de 6 dias, durante os quais foram registrados os comportamentos. A análise estatística adotada foi conduzida por meio de um modelo linear generalizado misto (GLMM) com distribuição de Poisson, utilizando o Software R (versão 3.34). Os resultados revelaram um aumento na agressividade tanto nos grupos de adultos quanto de filhotes no sexto dia. Destacou-se que os filhotes apresentaram maior responsividade e agressividade em comparação com os adultos. Este estudo proporcionou evidências claras de uma diferença ontogenética na escolha de estratégias defensivas entre filhotes e adultos. Tal distinção foi influenciada pela experiência, limitações e necessidades inerentes a cada fase de vida das serpentes. Contrariando as expectativas baseadas na literatura, ambos os grupos, filhotes e adultos, não manifestaram habituação aos estímulos apresentados, indicando, em vez disso, um fenômeno de sensibilização. Esses achados enfatizam a relevância de considerar as variáveis ontogenéticas ao analisar o comportamento defensivo em serpentes, particularmente no contexto das interações presa-predador. Além disso, os resultados possuem implicações práticas, especialmente em regiões onde a presença de cascavéis pode representar riscos para a comunidade. Este estudo contribui para uma compreensão mais aprofundada dos padrões de comportamento defensivo em cascavéis, fornecendo insights valiosos para estratégias de manejo e conservação em ambientes controlados.

Atividade diária, uso do ambiente e comportamento reprodutivo de Bothrops sazimai, espécie criticamente ameaçada, em cativeiro

The genus Bothrops, popularly know as the jararacas group, currently has 32 species in Brazil. They are found both at the sea level and at altitudes close to 3000m, and some species unhabitat continental islands. One of these species is Bothrops sazimai, described in 2016, a snake endemic to Ilha dos Franceses which, due to anthropogenic pressure in its natural environment, is considered a critically endangered species. Therefore, maintaning this speciesw in captivity can help to understand its behavior, biology and environmental use. In this work, through monitoring over 15 days, it was possible to characterize the daily activity, environmental use and reproductive behavior of two individuals of B. sazimai, and conclude that the species presentes nocturnal activity and semi-arboreal habits, despite using the lower stratum more frerquently. This work also presentes aspects of reproductive behavior in captivity, showing that the courtship behavior of B. sazimai is similar to the behavior of other snakes of the genus Bothrops, which basically involves a phase of pursuit, alignment and introduction of the hemipenis. To date, the information available on B. sazimai is limited to the work describing the species, therefore, the information obtained through this work is unprecedented.

O gênero Bothrops, conhecido popularmente como grupo das jararacas apresenta atualmente, no Brasil, 32 espécies. São encontradas tanto ao nível do mar, quanto em altitudes próximas a 3000m, e algumas espécies habitam ilhas continentais. Uma dessas espécies é a Bothrops sazimai, descrita em 2016, serpente endêmica da Ilha dos Franceses que, devido à pressão antropogênica em seu ambiente natural, é considerada uma espécie criticamente ameaçada. Dessa forma, a manutenção dessa espécie em cativeiro pode auxiliar no conhecimento do comportamento, biologia e uso do ambiente. Neste trabalho, através do monitoramento ao longo de 15 dias, foi possível caracterizar a atividade diária, uso do ambiente e comportamento reprodutivo de dois indivíduos de B. sazimai, e concluir que a espécie apresenta atividade noturna e hábitos semi arborícolas, apesar de usar o estrato inferior com mais frequência. Este trabalho também apresenta aspectos do comportamento reprodutivo em cativeiro, mostrando que o comportamento de corte de B. sazimai é semelhante ao comportamento de outras serpentes do gênero Bothrops, que envolve basicamente a fase de perseguição, alinhamento e introdução do hemipenis. Até o momento, as informações disponíveis sobre B. sazimai limitam-se ao trabalho de descrição da espécie, sendo assim, as informações obtidas por este trabalho são inéditas.

Stable isotopic composition of Bothrops atrox (common lancehead) in four distinct land covers in eastern Amazonia

Since consumers reflect the isotopic composition of an assimilated diet, stable isotopes can be a useful tool to address the feeding ecology of tropical snakes. This is the first study reporting carbon and nitrogen stable isotopic composition of Bothrops atrox (Linnaeus, 1758) living in different landscapes located in the lower Amazon river, encompassing four main natural landscapes of the Amazon: old-growth forests, várzeas (flooded forests), savannas, and pastures. Our null hypothesis is that the δ13C of forest specimens of B.atrox is more negative because forests are dominated by C3 plants, while C4 plants are common in the other landscapes. On the other hand, δ15N of forest specimens should be more positive, since the δ15N of old-growth forests are higher than plants of savanna, várzea, and pastures. Confirming our hypothesis, the δ13C of B. atrox scales of the Tapajós National Forest was approximate −25‰ to −24‰, increased to approximately −23.5‰ to −23.0‰ in the savanna and pasture, and to −21‰ in the várzea, showing an increased contribution of C4-derived carbon. Some specimens of B. atrox had δ15N as high as 18‰, which is much higher than the average δ15N of the snake's prey (7‰), confirming the apex position of B. atrox in the Amazon region. The δ15N values of the forest specimens were 5‰ higher than the savanna specimens, and this difference decreased to 3‰ between the forest and the pasture, and the várzea specimens. Finally, there were not large differences between δ15N values of livers and scales in any of the landscapes, suggesting a constant diet through time, and reinforcing the possibility of the use of snake's scale as a less invasive and non-lethal tissue to analyze.