Water Dragons Research Articles

The genome of the Australian water dragon (Intellagama lesueurii), an agamid model for urban adaptation.

Squamate reptiles are a highly diverse and intriguing group of tetrapods, offering valuable insights into the evolution of amniotes. The Australian water dragon (Intellagama lesueurii) is a member of the Agamidae, and sister to the core mesic Australian endemic radiation (Amphibolurinae). The species is renowned for its urban adaptability and complex social systems. We report a 1.8 Gb chromosome-length genome assembly together with the annotation of 23,675 protein-coding genes. Comparative analysis with other squamate genomes highlights gene family expansions associated with immune function, energetic homeostasis, and wound healing. This reference genome will serve as a valuable resource for studies of evolution and environmental resilience in lizards.

The quick and the fed: Geographical variation in embryonic development and offspring size in a wide‐spread lizard

AbstractBroad geographical distributions that include marked climatic variation may expose populations to distinct selective pressures. Local adaptation to differences in developmental conditions may lead to divergence in embryonic and hatchling traits for populations of oviparous reptiles. Among‐population differences in hatchling size and the duration of development are often observed in lizards with wide and climatically diverse distributions. Variation in hatchling phenotypes can arise from variation in maternal allocation, developmental plasticity or selection acting on embryonic traits. We studied variation in hatchlings of the Australian water dragon (Intellagama lesueurii), comparing traits related to growth and patterns of developmental plasticity. We recorded marked differences in hatchling sizes among populations from different climate types, which did not result from differences in maternal investment or from a plastic response to incubation temperatures. Embryos from southern, temperate populations exhibited shorter incubation times when incubated at cold temperatures but utilized less yolk during development and hatched smaller, with more residual yolk, regardless of incubation treatment. We suggest that these findings represent the first example of among‐population variation in patterns of embryonic resource allocation and a novel mechanism mediating offspring size in reptiles. We further suggest that variation in embryonic resource allocation in I. lesueurii, together with evolutionary changes in reaction norms for developmental rate, evolved as adaptations to seasonal length and conditions associated with a tropical‐temperate gradient.

Ecological Correlates of Small Territories and Intra-Seasonal Variation in the Social Context of Displays in Male Water Dragons, Intellagama lesueurii

Ecological Correlates of Small Territories and Intra-Seasonal Variation in the Social Context of Displays in Male Water Dragons, Intellagama lesueurii

Adaptive significance of affiliative behaviour differs between sexes in a wild reptile population.

In recent years, we have begun to appreciate that social behaviours might exhibit repeatable among-individual variation. Such behavioural traits may even covary and have critical evolutionary implications. Importantly, some social behaviours such as aggressiveness have been shown to provide fitness benefits, including higher reproductive success and survival. However, fitness consequences of affiliative behaviours, especially between or among sexes, can be more challenging to establish. Using a longitudinal behavioural dataset (2014-2021) collected on eastern water dragons (Intellagama lesueurii), we investigated whether various aspects of affiliative behaviour (i) were repeatable across years, (ii) covaried with each other at the among-individual level, and (iii) influenced individuals' fitness. In particular, we considered affiliative behaviours towards opposite-sex and same-sex conspecifics separately. We found that social traits were repeatable and covaried with each other similarly for both sexes. More notably, we found that male reproductive success was positively correlated with the number of female associates and the proportion of time spent with females, while females' reproductive success was not correlated with any of the measured social behaviour metrics. Overall, these findings suggest that selection may be acting differently on social behaviour of male and female eastern water dragons.

Agonism does not covary with territoriality in a gregarious reptile

Natural selection for territoriality is theorised to occur under conditions favouring intra-sexual phenotypic variation in physiology, morphology, and behaviour. In this context, certain suites of behavioural traits associated with territoriality are expected to consistently covary among individuals (sometimes referred to as ‘behavioural syndromes’) within sexes. Agonism (conflict-associated behaviours that may or may not be associated with physical aggression) and movement—for example, ranging, or relocation within or across seasons—are two behavioural components that are associated with territoriality and may be expected to covary in this context. Territorial males are expected to employ agonistic behaviours to actively establish and defend areas and resources and show more stability in their location across the landscape. However, the interaction between agonism and movement especially for wild reptiles has rarely been tested. We investigated whether agonistic and movement behaviours correlate at the individual level both within one year and across multiple years, in a wild population of Australian eastern water dragons, Intellagama lesueurii. Although both types of behaviours exhibited among-individual repeatability over year and multi-year scales, we found no evidence of an agonistic-movement behavioural syndrome. These findings indicate that agonistic and movement behaviours are likely independent traits, and thus, territoriality may not drive shared selective pressures for both. It is possible that other social behaviours and strategies are in place to maintain social structure in this wild population.Significance statementMales of many animals establish and maintain or defend territories. Territory defence is expected to be associated with behaviours associated with conflict or expressions of dominance, to signal territory boundaries to encroaching individuals, or more aggressive approaches for active defence. We investigated whether such agonistic behaviours correlated with the distances individuals ranged or dispersed within and between years, as an indicator of territoriality. Through thousands of observations of a wild population of Australian eastern water dragons, Intellagama lesueurii, we found that although individuals showed repeatable patterns of both agonistic and movement behaviours, we found no evidence that these were correlated. It appears that territory establishment and defence may therefore not rely on agonistic signals in this species in direct contrast to other taxa, indicating that other systems are in place to maintain social structures.

Digest: Parks aren't just for us: city parks as archipelagos for the study of rapid evolution.

Can city parks provide adequate environments for studying rapid evolution? Jackson et al. (2022) found divergent selection is contributing to significant rates of phenotypic divergence across city populations of the eastern water dragon (Intellagama lesueurii), suggesting city green spaces may be ideal for the study of rapid evolution in urban populations.

Selection in the city: Rapid and fine-scale evolution of urban eastern water dragons.

Oceanic archipelagos have long been treated as a Petri dish for studies of evolutionary and ecological processes. Like archipelagos, cities exhibit similar patterns and processes, such as the rapid phenotypic divergence of a species between urban and nonurban environments. However, on a local scale, cities can be highly heterogenous, where geographically close populations can experience dramatically different environmental conditions. Nevertheless, we are yet to understand the evolutionary and ecological implications for populations spread across a heterogenous cityscape. To address this, we compared neutral genetic divergence to quantitative trait divergence within three native riparian and four city park populations of an iconic urban adapter, the eastern water dragon. We demonstrated that selection is likely acting to drive divergence of snout-vent length and jaw width across native riparian populations that are geographically isolated and across city park populations that are geographically close yet isolated by urbanization. City park populations as close as 0.9km exhibited signs of selection-driven divergence to the same extent as native riparian populations isolated by up to 114.5km. These findings suggest that local adaptation may be occurring over exceptionally small geographic and temporal scales within a single metropolis, demonstrating that city parks can act as archipelagos for the study of rapid evolution.

Reptiles and Amphibians on a University Campus in a Peri-urban Area of Sydney, New South Wales, Australia

Building upon a previous species inventory published in 2004 and based on observations between 2008 and 2011, I herein describe the reptile and amphibian assemblage on a university campus in the northwestern corner of the Sydney metropolitan area, Australia, recording 26 species of reptiles in nine families (Chelidae, Agamidae, Carphodactylidae, Scincidae, Varanidae, Typhlopidae, Colubridae, Elapidae, Pythonidae) and 13 species of amphibians in three families (Pelodryadidae, Limnodynastidae, Myobatrachidae). Included are records of the Macquarie Turtle (Emydura macquarii) and Eastern Water Dragon (Intellagama lesueurii lesueurii), neither of which were considered indigenous to the campus in the previous inventory, and one observation of two Ornate Burrowing Frogs (Platyplectrum ornatum), which previously were thought to be only historically present at the site. Seven species predicted to be present on the campus by the previous inventory were confirmed by observations in this study. These observations demonstrate how green spaces on the periphery of one of the world’s largest cities can harbor a diverse assemblage of reptiles and amphibians.

What to Read Now: Young Adult Lit

What to Read Now:Young Adult Lit Laura Hernandez (bio) I THINK I WILL FOREVER be just a little bit in love with young adult (YA) literature, no matter how old I get. While I’m not terribly discriminatory about genres, I do have steadfast favorites: fantasy, dystopian, historical fiction, and sci-fi. There are popular tropes that show up across all—found family, fake dating, enemies to lovers, reluctant royalty, etc.—and it’s enjoyable to dive into a book that doesn’t hold any punches and jumps right into the story. YA isn’t afraid to wrestle with big questions or tackle difficult topics, and the books’ main characters are often saving the world while also dealing with the soul-crushing monotony of high school. There’s been a rise in BIPOC YA literature showcasing different identities and cultural backgrounds. We all have different frameworks for how we view the world based on our experiences and how we grew up, but I love seeing the world from another perspective. Whether that’s through how an Iranian immigrant daughter handles culture shock after moving to America or an Afro-Latina navigating high school while raising a toddler, I always learn when I read a novel from a different perspective and am better for it. Yamile Saied Méndez Furia Algonquin Young Readers Set in Argentina, Furia follows Camila (La Furia), who wants to pursue her fútbol dream but feels trapped by family obligations and a narrow view of what women can do with their lives. She has to keep her ambitions a secret from her parents, but inside she longs to see how far her talents could take her. This novel touched on so many emotional and poignant aspects—family dynamics, trust, first love, pursuing your dreams, and standing up for yourself. I was completely mesmerized and rooting for La Furia the entire time. The overall story carefully and beautifully weaves Camila’s love for her family and her growth in figuring out her dreams while fighting for them. Elizabeth Lim Six Crimson Cranes Knopf Books for Young Readers I was pretty much destined to fall in love with Six Crimson Cranes because it features one of my favorite genres: diverse fairy-tale retellings. If you’re familiar with the Six Swans story, then you’ll love this rendition, which pulls from Asian mythology and expertly draws in new elements, like a dubiously helpful and mysterious water dragon and an enchanted paper bird sidekick. Princess Shiori has forbidden magic, and on the morning of her betrothal ceremony, she accidentally loses control and is cursed by her stepmother. Her six brothers are turned into cranes and she isn’t able to talk, for if she utters one word, one of her brothers will die. She has to find a way to break the curse and turn her brothers back into humans, all without speaking. Elizabeth Lim has written a beautiful and lyrical story that captures you from the beginning with her rich world development and captivating portrayal of magic, mythology, romance, and adventure. Joan He The Ones We’re Meant to Find Roaring Brook Press If I had one word to describe this novel, I’d use unsettling, but in the best possible way. You’re quickly pulled into this dystopianesque environmental thriller, and the novel switches back and forth between two young women. Cee can’t remember how she ended up on this abandoned island, but all she knows is that she needs to find her sister, Kay. Kasey Mizuhara is a STEM prodigy and lives in a carefully maintained eco-city that protects its residents from natural disasters due to climate change. Kasey’s sister, Celia, is missing, and she’s determined to find out what happened. The story has an eerie quality that pulls you in instantly, giving you just enough glimpses to make you think you know what’s happening, before turning everything on its head in the next chapter. Even when I thought I had figured out how the stories intersected, the author would reveal a new detail that would leave me astonished. [End Page 9] Laura Hernandez Laura Hernandez lives and writes in...

Small Breeding Season Home Ranges and Egg-Laying Migrations in Urban Female Water Dragons (Intellagama lesueurii)

Ecologists have a long-standing interest in the size of animal home ranges, including those of lizards, but studies on females are relatively rare and often do not take into account possible space use changes in relation to the breeding cycle. We mapped locations of female Eastern Water Dragons (Intellagama lesueurii) daily, during the 2009 and 2016 breeding seasons in relation to reproductive status. Home ranges of all females bordered water and overlapped with areas used by other females. Average home range area was similar between 2009 and 2016, and home range size was not correlated with female size. Six surviving females used part of the same areas in both years. The average ratio of home range area to female size (standardized to linear dimensions) in Water Dragon females was only 13.6% that of 25 other large lizard species, and only 10.6% of estimates during and outside of the breeding season in another urban Water Dragon population. In our population, 38% (25 of 65) made temporary (1 d) departures from their usual home ranges. Palpation revealed that ripening eggs were present prior to departure but absent when females returned, and two of these females were observed digging nests during migrations. Short-term egg-laying migrations may reduce intergenerational competition resulting from strong philopatry in female Water Dragons. Our results reveal how repeated observations of individuals throughout critical periods, such as during the breeding season, can reveal subtle details in use of space that are likely important for the fitness of individuals.

Morphological characteristics and mitochondrial COI gene of the green water dragon in Phu Quoc island, Vietnam

The green water dragons of Phu Quoc island, Vietnam have been given a VU rating (vulnerable) by the Vietnam red data book and the International Union for conservation of nature and natural resources. A description of the morphological characteristics and sequenced mitochondrial cytochrome oxidase subunit 1 COI gene was completed following a survey of thirty individuals from September 2018 to May 2019. Their body weights ranged from 115 to 850 g and their snout-vent length ranged from 120 to 280 mm. They were identified to have the highest similarity to the species Physignathus cocincinus by the barcode of life data system. Their COI gene sequence was compared to GenBank (KM272197.1) and the following alternations were found: C5483T, A5486C, C5537A, A5564G, A5591G, T5633C, G5684A, A5771G, A5849C, C5927T, T5942C, C5993T, G6002A, and A6020G. The neighbourjoining tree of their COI sequence divergence indicated a distance (compared to the same published species) from 2.3 to 2.8%. Thus, it might be possible that the green water dragons of Phu Quoc island are evolving into a specific subspecies. However, more green water dragon specimens from Phu Quoc should be sequenced to ensure a conclusion and further research into farming should be initiated to protect this vulnerable species.

Repeatability and heritability of social reaction norms in a wild agamid lizard.

In the evolutionary transition from solitary to group living, it should be adaptive for animals to respond to the environment and choose when to socialize to reduce conflict and maximize access to resources. Due to the associated proximate mechanisms (e.g. neural network, endocrine system), it is likely that this behavior varies between individuals according to genetic and non-genetic factors. We used long-term behavioral and genetic data from a population of eastern water dragons (Intellagama lesueurii) to explore variation in plasticity of social behavior, in response to sex ratio and density. To do so, we modeled individual variation in social reaction norms, which describe individuals' mean behavior and behavioral responses to changes in their environment, and partitioned variance into genetic and non-genetic components. We found that reaction norms were repeatable over multiple years, suggesting that individuals consistently differed in their behavioral responses to changes in the social environment. Despite high repeatability of reaction norm components, trait heritability was below our limit of detection based on power analyses (h2 < 0.12), leading to very little power to detect heritability of plasticity. This was in contrast to a relatively greater amount of variance associated with environmental effects. This could suggest that mechanisms such as social learning and frequency-dependence may shape variance in reaction norms, which will be testable as the dataset grows.

The Water Dragon and the Snake Witch: Two Vendel Period Picture Stones from Gotland, Sweden

The style and iconography of two well­known picture stones are re­analysed. The Hablingbo Havor II pic­ ture stone shows a motif that occurs frequently in Got­ landic art from the Vendel Period onwards: the“Water Dragon”. It is suggested that this relates to an ideo­ logical connection between the dragon and the sea, where the sea is the dragon that ferries ships to distant shores. This is reflected not only in picture stones, but in Viking Age art in general. The iconography of När Smiss III (the “Snake Witch”) has been interpreted in a variety of ways, but special consideration is given to Peel’s (1999) suggestion that it relates closely to the Vi­ tastjärna myth from the 13th­century Guta Saga. The artistic style of the zoomorphs on both stones (Style II) is typically dated to the Vendel Period. It is suggested that Sune Lindqvist’s insistence that the stones date from before AD 600 comes from a long­standing de­ bate with Nils Åberg over the date and context of the east mound at Uppsala, and by association, the date of the artistic style found on Hablingbo Havor II and När Smiss III. This debate has been resolved in favour of Åberg’s interpretation. These two picture stones rep­ resent an artistic tradition that should be dated con­ servatively from the beginning of the 5th century AD to the middle of the 7th century AD.

Genome Sequence of the Fungus Nannizziopsis barbatae, an Emerging Reptile Pathogen.

Nannizziopsis barbatae is an emerging fungal pathogen capable of causing contagious dermatomycosis in reptiles. Here, we report a 31.54-Mb draft genome sequence of an isolate originating from an infected eastern water dragon in Brisbane, Australia.

Water Dragon Boat Training Monitoring System Based on Multisensor Data Fusion Technology

With the development of science and technology, a variety of electronic devices have entered our lives, making our lives more intelligent and making our work more effective. This article is aimed at studying the application of multisensor data fusion technology to the water dragon boat training monitoring system. In that case, we can analyze the various physical indicators of dragon boat athletes based on the data reflected by these sensors, when they can reach their physical limits and can perform in the best state to obtain the best results. The sensor is used to decompose the relevant data of each part of the athlete’s limbs. This step is based on the image and understands the maximum value of the data to adjust the training goal. This article proposes some data fusion algorithms, using Kalman filter method, Bayesian estimation method, and DS evidence theory algorithm to compare data fusion systems, through the comparison to find the best fusion accuracy, and then get the most suitable method is then applied to this water dragon boat monitoring system to enhance the training efficiency of dragon boat athletes. The experimental results in this paper show that when the value of the parameter increases from 0.97 to 2.5, the average classification accuracy of the k‐NN classifier decreases from 0.97 to 0.4, and the accuracy of the fusion results of the three fusion rules is also reduced correspondingly, but in this paper proposed, RP fusion rule still has better performance than the other two fusion rules. When the classifier is k‐NN, the three fusion rules increase with the number of sensors, and the accuracy of the fusion results is correspondingly improved. However, the final fusion accuracy obtained by the RP fusion rule proposed in this paper is always better than NB integration rules, and WMV integration rules are higher. Through these analyses, a training program that is most suitable for dragon boat athletes can be worked out, so that the athletes will not be useless. Multisensor data fusion technology brings great convenience to water dragon boat training and can provide more reasonable and accurate data to explore a practical way on the basis of ensuring the safety of personnel.

Cross-continental emergence of Nannizziopsis barbatae disease may threaten wild Australian lizards

Members of the genus Nannizziopsis are emerging fungal pathogens of reptiles that have been documented as the cause of fatal mycoses in a wide range of reptiles in captivity. Cases of severe, proliferative dermatitis, debility and death have been detected in multiple free-living lizard species from locations across Australia, including a substantial outbreak among Eastern water dragons (Intellagama lesueurii) in Brisbane, Queensland. We investigated this disease in a subset of severely affected lizards and identified a clinically consistent syndrome characterized by hyperkeratosis, epidermal hyperplasia, dermal inflammation, necrosis, ulceration, and emaciation. Using a novel fungal isolation method, histopathology, and molecular techniques, we identified the etiologic agent as Nannizziopsis barbatae, a species reported only once previously from captive lizards in Australia. Here we report severe dermatomycosis caused by N. barbatae in five species of Australian lizard, representing the first cases of Nannizziopsis infection among free-living reptiles, globally. Further, we evaluate key pathogen and host characteristics that indicate N. barbatae-associated dermatomycosis may pose a concerning threat to Australian lizards.

Shrinking into the big city: influence of genetic and environmental factors on urban dragon lizard morphology and performance capacity

Urban wildlife faces a novel set of challenges resulting in selective pressure that can lead to population-level changes. We studied Australian water dragons (Intellagama lesueurii) from urban and natural populations to test if urban populations differed in body size, shape, and performance capacity. If urban-derived morphology has arisen through selection, we predicted distinct morphological differences between wild dragons from urban and natural areas in both adult and hatchling life-stages. Urban hatchlings were morphologically distinct (shorter body lengths and longer limbs) from natural populations, while urban adult males continued this trend but only for body size (shorter body lengths). We then experimentally reared hatchlings originating from urban and natural populations within urban- and natural-style enclosures (2 × 2 factorial design) for a year to determine if differences in morphology and performance capacity (sprint speed, endurance, and clinging ability) were related to either the individual’s origin population or developmental environment. Yearlings reared in urban-style enclosures, irrespective of population origin, had smaller body sizes compared to those from natural-style enclosures, suggesting developmental environment was affecting their morphology. Despite this difference in body size, yearling dragon performance capacity was not significantly different between treatments. Overall, this study provides evidence of a complex relationship driving urban-divergent morphology – whereby urban dragons emerge as smaller hatchlings with longer limbs (innate traits) and are then further influenced by the urban environments that they develop in (phenotypic plasticity); however, and potentially owing to behavioral, ecological, and demographical differences, these changes appear to be sex-specific.

Lies of Solidarity: Naga Fireballs, Terrorist Detectors, and Affiliational Lies in Thailand

ABSTRACT What are we saying when we lie? Here, I examine two hoaxes in Thailand: a fisherman manufactures evidence of nagas – water dragons – in his town to counter mining claims and Thai security forces double down on the use of a discredited bomb detector. Building on Michael Herzfeld’s cultural intimacy, I argue that these lies do not ask for resolution with ‘truth’, rather, they build a community via provoking a kind of doublethink, calling for the interlocutor to affirm that certain truths are true only in the ideal, at certain times, or at an unresolved future point. Thus, lies are an invitation to a solidarity that remains unspoken: an acknowledgement of a ‘resonance’ that remains unsaid, and a presentation of a world that is still malleable.

Crossing Lydekker's Line: Northern Water Dragons (Tropicagama temporalis) Colonized the Mollucan Islands of Indonesia from New Guinea

Wallace's and Lydekker's Lines both describe important biogeographic barriers in the Indo-Australian Archipelago, with Wallace's Line demarcating the boundary of the Greater Sunda Shelf and Lydekker's Line indicating the edge of the Sahul continental shelf. Despite their similarities, Wallace's Line has been much more heavily studied than has Lydekker's Line, yet provides an interesting system for testing the source of fauna into eastern Wallacea. New collections of Northern Water Dragons, Tropicagama temporalis, from several islands in Maluku, eastern Indonesia now allow for an assessment of the phylogeography of the species and the ability to test if New Guinean or Australian populations served as the source for over-water dispersal across Lydekker's Line into Maluku. We collected specimens from remote islands in eastern Indonesia, sequenced the mitochondrial ND2 gene, and aligned the data to previously sequenced specimens on GenBank. We conducted several phylogenetic and divergence time analyses to investigate the source population and timing of dispersal. We found low genetic diversity among the islands in Maluku, and these samples showed little genetic divergence from New Guinea samples. The New Guinea and Maluku populations diverged less than 1 million years ago (Ma) and together diverged from the Australian population between 2.3 and 4.7 Ma. These results, along with patterns in other taxa, illustrated that, despite Australia's close geographic proximity to many of the islands in southeastern Indonesia, New Guinea has been the more frequent source of Wallacean fauna from Sahul.

Population assessment and impact of trade on the Asian Water Dragon (Physignathus cocincinus Cuvier, 1829) in Vietnam

Physignathus cocincinus has been harvested in Vietnam for the local food market as well as for the international pet trade since at least 20 years. However, comprehensive knowledge about its global conservation status is lacking so far. Our study was conducted to evaluate potential impacts of harvest and trade on wild populations by providing an overview of the international and domestic trade in P. cocincinus in Vietnam. To assess the level of anthropogenic impacts on wild populations, we compared population densities and sizes of an undisturbed and several disturbed sites in northern Vietnam between 2014 and 2016 by using a mark-recapture method. The results indicate that mean densities are smaller in disturbed populations than in the reference population. Imports of 1.47 million individuals, mainly of wild origin from Vietnam, into the EU and US were documented in the last 20 years. Regarding national pet trade, a total of 51 domestic dealers and nine online pet shops trading P. cocincinus were documented in Vietnam since 2015. Our study also highlights a considerable harvest for the national use, viz. pet trade and food consumption, in Asian range states. We assume that the long-term viability of P. cocincinus in the Indo-China region, at least in the North of Vietnam, is at risk due to the considerable extent of harvest and ongoing habitat degradation. Thus, we suggest stringent conservation measures to protect wild populations more efficiently and improve habitat conservation.