Differences in kinematic plasticity between freshwater turtle species underlie differences in swimming performance in response to varying flow conditions

Abstract The distribution and performance of aquatic vertebrates can be linked strongly to their ability to perform in variable conditions of flowing water. Performance in these variable conditions can be affected by both morphology and behaviour, and animals that experience more variable environments often show greater behavioural plasticity that improves performance in those environments. One common metric of performance is swimming stability, which can constitute a majority of the daily energy budget of swimming animals. We compared the body oscillations arising from recoil forces of the limbs of two species of freshwater turtles as they swam in different flow conditions: the lentic specialist Emydura subglobosa and the habitat generalist Chrysemys picta. We found that E. subglobosa experienced more limited oscillations in still water than C. picta, but that C. picta had a greater kinematic response to increased flow speed that might contribute to their improved performance in flowing water. These results provide insight into how secondarily aquatic tetrapods respond to the functional demands of variation in flow, helping to build understanding of the relationship between energetics, kinematics and performance of such lineages in different environments.

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Plastic ingestion by freshwater turtles: a review and call to action

Scientific Reports ◽

10.1038/s41598-021-84846-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adam G. Clause ◽

Aaron J. Celestian ◽

Gregory B. Pauly

Keyword(s):

Marine Species ◽

Marine Turtle ◽

Freshwater Turtle ◽

Freshwater Turtles ◽

Plastic Pollution ◽

Potential Threat ◽

Implementation Quality ◽

Turtle Species ◽

Marine Turtles ◽

Conservation Concern

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.

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Formation of Kinneyia via shear-induced instabilities in microbial mats

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2012.0362 ◽

2013 ◽

Vol 371 (2004) ◽

pp. 20120362 ◽

Cited By ~ 25

Author(s):

Katherine Thomas ◽

Stephan Herminghaus ◽

Hubertus Porada ◽

Lucas Goehring

Keyword(s):

Microbial Mats ◽

Flow Speed ◽

Glass Beads ◽

Flowing Water ◽

Flow Conditions ◽

Theoretical Predictions ◽

Laboratory Analogue ◽

Littoral Habitats ◽

Over Time ◽

Ripple Pattern

Kinneyia are a class of microbially mediated sedimentary fossils. Characterized by clearly defined ripple structures, Kinneyia are generally found in areas that were formally littoral habitats and covered by microbial mats. To date, there has been no conclusive explanation of the processes involved in the formation of these fossils. Microbial mats behave like viscoelastic fluids. We propose that the key mechanism involved in the formation of Kinneyia is a Kelvin–Helmholtz-type instability induced in a viscoelastic film under flowing water. A ripple corrugation is spontaneously induced in the film and grows in amplitude over time. Theoretical predictions show that the ripple instability has a wavelength proportional to the thickness of the film. Experiments carried out using viscoelastic films confirm this prediction. The ripple pattern that forms has a wavelength roughly three times the thickness of the film. This behaviour is independent of the viscosity of the film and the flow conditions. Laboratory-analogue Kinneyia were formed via the sedimentation of glass beads, which preferentially deposit in the troughs of the ripples. Well-ordered patterns form, with both honeycomb-like and parallel ridges being observed, depending on the flow speed. These patterns correspond well with those found in Kinneyia, with similar morphologies, wavelengths and amplitudes being observed.

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Population status and distribution of freshwater turtles in Taiwan

Oryx ◽

10.1017/s0030605310000013 ◽

2010 ◽

Vol 44 (2) ◽

pp. 261-266 ◽

Cited By ~ 9

Author(s):

Tien-Hsi Chen ◽

Kuang-Yang Lue

Keyword(s):

Native Species ◽

Mainland China ◽

Iucn Red List ◽

Freshwater Turtle ◽

Freshwater Turtles ◽

Chinese Market ◽

Negative Effects ◽

Turtle Species ◽

Mauremys Mutica ◽

Effective Conservation

AbstractBecause of burgeoning demand in the Chinese market and extensive habitat loss more than half of the freshwater turtle and tortoise species in Asia are categorized as Endangered or Critically Endangered on the IUCN Red List. To investigate the distribution and status of the native freshwater turtle species of Taiwan a trapping programme was conducted during 2001–2007, yielding a total of 1,828 individuals of four native species at 103 sites. Mauremys sinensis was the most abundant and widely distributed species; it was collected from 70 sites and accounted for 78.6% of all turtles captures. Mauremys mutica comprised 17.8% at 46 sites. Pelodiscus sinensis were captured in low numbers at 19 sites. No Mauremys reevesii were collected on the main island of Taiwan but the species was found on Kinmen Island near mainland China. Capture success was low at most sites and overall sex ratios were significantly male-biased in all species, suggesting that the freshwater turtles have suffered from the negative effects of habitat disturbance and extensive exploitation. Effective conservation measures are urgently required to ensure the viability of the native freshwater turtle species of Taiwan.

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Impacts of dams on freshwater turtles: a global review to identify conservation solutions

10.1101/2021.10.21.465338 ◽

2021 ◽

Author(s):

Andrea Barcenas-Garcia ◽

Fernanda Michalski ◽

William H. Morgan ◽

Rebecca K. Smith ◽

William J. Sutherland ◽

...

Keyword(s):

Freshwater Ecosystems ◽

Freshwater Turtle ◽

Tropical Species ◽

Life History Stage ◽

Freshwater Turtles ◽

Tropical Regions ◽

Turtle Species ◽

Threat Status ◽

Dam Impacts ◽

The Impact

Dams create many impacts on freshwater ecosystems and biodiversity. Freshwater turtles are at direct and indirect risk due to changes caused by damming including the loss of terrestrial and aquatic nesting and feeding habitats, changes to resource availability and reduced dispersal. We reviewed the global scientific literature that evaluated the impact of dams on freshwater turtles, and carried out additional searches of literature published in seventeen languages for studies evaluating actions to mitigate the impact of dams. The search produced 43 published articles documenting dam impacts on 29 freshwater turtle species from seven families (Chelidae, Chelydridae, Emydidae, Geoemydidae, Kinosternidae, Podocnemididae and Trionychidae) in 13 countries. More than a third of studies (41.9%, n = 18) focused on nine North American species of the Emydidae. Few studies were found from Europe and Asia and none from Africa. The number of studies, life-history stage studied and threat status differed significantly between temperate and tropical latitudes. Most studies were from temperate latitudes, where studies focused more on adults and less threatened species compared with tropical latitudes. Studies evaluated dam impacts as barriers and changes to water flow and quality, but no studies were found that assessed turtles and changes to land cover or mercury caused by dams. More than half of the studies (59%, n = 24) suggested actions to help mitigate dam impacts. Yet, only four studies on three temperate and one tropical species documented the effect of interventions (dam removal, flow management, artificial pond maintenance and community-based action). These findings demonstrate a lack of documented evidence evaluating dam impacts on freshwater turtles particularly in tropical regions. This lack of evidence reinforces the importance of strengthening and maintaining robust long-term studies of freshwater turtles needed to develop effective conservation actions for this group of vertebrates.

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Body temperature of free-living freshwater turtles, Hydromedusa maximiliani (Testudines, Chelidae)

Amphibia-Reptilia ◽

10.1163/156853806778189990 ◽

2006 ◽

Vol 27 (3) ◽

pp. 464-468 ◽

Cited By ~ 6

Author(s):

Fernando Martins ◽

Franco Souza

Keyword(s):

Body Temperature ◽

Water Temperature ◽

Stream Water ◽

Life Stage ◽

Freshwater Turtle ◽

Freshwater Turtles ◽

Body Temperatures ◽

Turtle Species ◽

Mountainous Regions ◽

Main Factor

AbstractField body temperatures of the Maximilian's snake-necked turtle, Hydromedusa maximiliani, a small freshwater turtle species endemic to Atlantic rainforest mountainous regions in Brazil, were studied. Turtle body temperatures and water temperatures were significantly related, but turtle body temperature averaged 1°C higher than stream water temperature, this difference being statistically significant. A multivariate model revealed that only water temperature was significantly related to turtle body temperature while body size had no effect. There was no effect of sex and life stage on turtle body temperature, implying that water temperature was the main factor determining body temperatures. Thermoconformity was verified for all sampled individuals. The broad implications of these results are also discussed.

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Ecology and Genetic Identification of Freshwater Turtles in Pakistan

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.113136 ◽

2021 ◽

Vol 49 ◽

Author(s):

Muhammad Qayash Khan ◽

Yaseen, Hafsa Zahid ◽

Muhammad Numan ◽

Itabajara Da Silva Vaz Jr. ◽

Abid Ali

Keyword(s):

Genetic Identification ◽

Freshwater Turtle ◽

12S Rrna ◽

Rrna Gene ◽

Water Type ◽

Freshwater Turtles ◽

Turtle Species ◽

Quality Of Water ◽

In Captivity ◽

Major Factors

Background: The turtle population plays an important role in sustaining the water ecosystem by minimizing pollution from water. The identification and molecular investigation of freshwater fauna is essential for conservation of the species that are near to extinction. The quality of water, type of flora, fauna, and environmental condition are the major factors that directly affect the distribution of freshwater turtles. Studies on the species diversity and habitat of freshwater turtle have not been focused previously in the region. The present study was the first conducted to estimate the habitat and genetic diversity of freshwater turtles using 12S rRNA (ribosomal RNA) gene in Pakistan.Materials, Methods & Results: A total of 26 samples were collected from various localities using hand net, cast net, gills net, steel hooks, thick chemical wire, using chicken intestine and small fishes. The collected turtle specimens were morpho-taxonomically categorized into two genera, Lissemys punctata andersoni (n=13, 50%) and Nilssonia gangetica (n=13, 50%). The collected species showed an aggressive and active behavior in captivity during summer. Genomic DNA was extracted from collected specimens and used in PCR reaction by using specific primers for the amplification of short fragments of 12S rRNA gene. Analysis of generated sequences confirmed the existence of L. p. andersoni in the region. The generated sequences of L. p. andersoni correspond to Clad A and showed a close resemblance among different species of the genus Lissemys.Discussion: This study is the first investigation about the habitat and of the endemic turtle species L. p. andersoni and N. gangetica in Pakistan. The genetic identification followed by phylogenetic analysis based on 12S rRNA partial genes revealed a closest similarity with the sequences generated for the same species from the neighboring countries. This study provided information to conduct further molecular studies that are essential to provide significant genetic data about turtle species.Keywords: turtle, ecology, diversity, phylogeny, Pakistan.

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Community Characteristics of Sympatric Freshwater Turtles From Savannah Waterbodies in Ghana

10.21203/rs.3.rs-303940/v1 ◽

2021 ◽

Author(s):

Suleman B. Gbewaa ◽

S. Kobby Oppong ◽

Brian D. Horne ◽

Paul Tehoda ◽

Fabio Petrozzi ◽

...

Keyword(s):

West Africa ◽

Correspondence Analysis ◽

Habitat Type ◽

Habitat Associations ◽

Emergent Vegetation ◽

Community Diversity ◽

Freshwater Turtle ◽

Physical Habitat ◽

Freshwater Turtles ◽

Turtle Species

Abstract Despite increasing pressures on freshwater resources worldwide, and the threatened status of most freshwater turtles, there is still limited knowledge of habitat use and niche partitioning in Afrotropical freshwater turtle communities. In this study, we describe habitat associations, community diversity, and temporal patterns of occurrence of freshwater turtle species in the Dahomey Gap ecoregion of Ghana (West Africa). We gathered data from 13 sites in central Ghana and along the Sene Arm of Lake Volta in the Digya National Park (Bono East Region). We employed opportunistic short-term surveys (at seven sites) together with longer-term (six-months duration) standardized evaluations of turtle presence and numbers in different habitats (at six sites). In addition, we interviewed fishers in the Lake Volta area to explore their perception about turtle abundance trends. Overall, 210 turtle individuals belonging to four species (Trionyx triunguis, Cyclanorbis senegalensis, Pelomedusa sp. and Pelusios castaneus) were recorded; for 139 individuals the precise capture sites and habitat type were recorded, whereas 71 individuals were observed in market places and were not considered in our analyses. We observed three sympatric species at the local scale of the various study sites. In each site, the dominant species was either C. senegalensis or Pelomedusa sp. However, Pelomedusa sp. was the most abundant species in temporary waterbodies whereas C. senegalensis was more numerous in permanent ones. A Multiple Correspondence Analysis visualized that, in permanent waterbodies all species were associated with similar physical habitat variables. C. senegalensis and T. triunguis were more abundant in localities containing woody emergent vegetation and inorganic substrate. In a Canonical Correspondence Analysis, we show that the density of herbaceous emergent vegetation was more important for P. castaneus than for C. senegalensis. Interviews with local people suggested that freshwater turtles do not have any special marketing interest for them, but that overfishing may have considerably affected the population density of these semiaquatic reptiles. Overall, Comparisons of diversity metrics between our study areas and previous literature revealed that turtle community composition was substantially the same, both qualitatively and quantitatively, all throughout the savannahs of West Africa.

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Transcending marine turtles: first report of hatching failure in eggs of Amazonian freshwater turtles with symptoms of the fungal emerging disease fusariosis

10.22541/au.163590446.60539987/v1 ◽

2021 ◽

Author(s):

Ana Sofía Carranco ◽

Mark A.F. Gillingham ◽

Kerstin Wilhelm ◽

María de Lourdes Torres ◽

Simone Sommer ◽

...

Keyword(s):

Fungal Pathogens ◽

Illumina Miseq ◽

Sea Turtle ◽

Marine Turtle ◽

Freshwater Turtle ◽

Freshwater Turtles ◽

Population Declines ◽

Turtle Species ◽

Podocnemis Unifilis ◽

Conservation Concern

In the last decades fungal pathogens are causing devastating population declines across a broad range of taxa. A newly emerging fungal disease, sea turtle egg fusariosis, caused by members of the Fusarium solani species complex (FSSC), has been reported to be responsible for hatching failure in sea turtles around the world. However, this has not been reported in other non-marine turtle species. Herein we report high hatching failure from eggs symptomatic of fusariosis in the yellow-spotted Amazon river turtle ( Podocnemis unifilis), inhabiting a pristine environment in the Ecuadorian Amazon. We assessed hatching success from eggs symptomatic and asymptomatic of fusariosis ( n = 680 eggs), tested for Fusarium infection by PCR amplifying the TEF-1α gene (n= 68 turtle internal egg swab samples) and sequenced eight amplicons for screening of FSSC membership on an Illumina Miseq. Hatchability was 72% for asymptomatic eggs, whilst only 8% of symptomatic eggs hatched. Eight percent of asymptomatic and 58% of symptomatic eggs tested positive for Fusarium spp. and sequencing revealed that nine sequence variants from three asymptomatic and four symptomatic eggs corresponded to F. keratoplasticum, F. solani and F. falciforme, the three major FSSC pathogens already reported in sea turtle egg fusariosis. Our study therefore suggests that observed hatching failure of eggs showing symptoms of fusariosis is at least partially caused by Fusarium pathogens within FSSC in a freshwater turtle. This report highlights that fusariosis is more widespread among the Testudines order than previously reported and is not limited to sea environments, which is of particular conservation concern.

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‘Man Is Ill Because He Is Badly Constructed’: Artaud, Klossowski and Deleuze in Search for the Earth Inside

Deleuze Studies ◽

10.3366/dls.2011.0003 ◽

2011 ◽

Vol 5 (1) ◽

pp. 18-34 ◽

Cited By ~ 1

Author(s):

Rick Dolphijn

Keyword(s):

Performance Art ◽

Holy Spirit ◽

The Body ◽

Deleuze And Guattari ◽

The Earth ◽

The Holy Spirit ◽

Life Itself ◽

Body Without Organs ◽

Ways Of Thinking ◽

And Performance

Starting with Antonin Artaud's radio play To Have Done With The Judgement Of God, this article analyses the ways in which Artaud's idea of the body without organs links up with various of his writings on the body and bodily theatre and with Deleuze and Guattari's later development of his ideas. Using Klossowski (or Klossowski's Nietzsche) to explain how the dominance of dialogue equals the dominance of God, I go on to examine how the Son (the facialised body), the Father (Language) and the Holy Spirit (Subjectification), need to be warded off in order to revitalize the body, reuniting it with ‘the earth’ it has been separated from. Artaud's writings on Balinese dancing and the Tarahumaran people pave the way for the new body to appear. Reconstructing the body through bodily practices, through religion and above all through art, as Deleuze and Guattari suggest, we are introduced not only to new ways of thinking theatre and performance art, but to life itself.

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Freshwater turtles of the TransFly region of Papua New Guinea - notes on diversity, distribution, reproduction, harvest and trade

Wildlife Research ◽

10.1071/wr05087 ◽

2006 ◽

Vol 33 (5) ◽

pp. 373 ◽

Cited By ~ 16

Author(s):

Arthur Georges ◽

Fiorenzo Guarino ◽

Biatus Bito

Keyword(s):

Papua New Guinea ◽

New Guinea ◽

Management Plan ◽

Transport Infrastructure ◽

Sufficient Information ◽

Freshwater Turtles ◽

Demographic Information ◽

Turtle Species ◽

Western Province ◽

High Diversity

The Chelidae is a family of side-necked turtles restricted in distribution to South America and Australasia. While their biology in Australia is reasonably well known, species in New Guinea are very poorly known despite high diversity, especially in the southern lowlands. In this paper, we report on the diversity, distribution, habitat and reproductive biology of the freshwater turtles of the TransFly region of the Western Province of Papua New Guinea, with special emphasis on reproduction of Emydura subglobosa, Elseya branderhorsti and Elseya novaeguineae. Seven species were captured, with reliable records of an eighth. A key to the freshwater turtles of the TransFly region is provided. Harvest methods, consumption, and trade in turtles by the TransFly communities are documented. There is mounting pressure to take advantage of revenue opportunities afforded by the Asian turtle trade, but this is impeded by lack of transport infrastructure. There is also insufficient demographic information on any New Guinean turtle species to make a reasoned judgment on the level of harvest that would be sustainable. Nor is there sufficient information on captive rearing for most species, and where it is available it is not accessible by local villagers. These knowledge gaps need to be addressed and factored into a management plan that is implemented before local communities can capitalise on the commercial opportunities provided by the turtle fauna without risking collapse of the resource and the implications for their concurrent subsistence economy that would follow.

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