Turtle

Biotic and abiotic factors play a crucial role in determining the distribution of species. These factors dictate the conditions that must be met for a species to thrive in a particular area. Sister species that present some degree of niche overlap can shed light on how they are distributed and coexist in their environment. This study aims to investigate the geographical distribution and ecological niche of the sister species of snake-necked turtles Hydromedusa maximiliani and H. tectifera . By analyzing their niche overlap, we aim to obtain a better understanding of how these two species coexist and which variables are determining their occurences...

Impressions of vertebrate bodies or their parts, such as trace fossils and natural molds of bones, are a valuable source of information about ancient faunas which may supplement the standard fossil record based on skeletal elements. Whereas trace fossils of animal activity are relatively common and actively studied within the field of ichnology, and natural impressions of internal or external surfaces are a frequent preservation mode in fossil invertebrates, natural molds of bones are comparatively rare and less extensively documented and discussed...

Coloration is often used in biological studies, for example when studying social signaling or antipredator defense. Yet, few detailed and standardized methods are available to measure coloration using digital photography. Here we provide a step-by-step guide to help researchers quantify coloration from digital images. We first identify the do's and don'ts of taking pictures for coloration analysis. We then describe how to i) extract reflectance values with the software ImageJ; ii) fit and apply linearization equations to reflectance values; iii) scale and select the areas of interest in ImageJ; iv) standardize pictures; and v) binarize and measure the proportion of different colors in an area of interest...

Fishing is one of the main threats to sea turtles due to the risk of entanglement in lost nets, vessel collision and mortality due to incidental catches. In Brazil, most of the studies regarding fishing interactions with sea turtles are focused on pelagic longline fisheries in the South and Southeast regions. However, their main reproductive areas in Southwest Atlantic RMU occur in Northeast Brazil, which overlaps small-scale coastal gillnet fisheries. Here, we aimed to use ethnobiology and participatory approaches as simple and cost-effective methods to identify areas for sea turtle conservation where impacts from small-scale fisheries are most likely...

The individual Geoffroy's side-necked turtle, Phrynops cf. P. geoffroanus, was diagnosed postmortem with osteosarcoma associated with the forelimb through morphological and histological analysis. Osteosarcoma stands as the most prevalent primary malignant bone tumor in tetrapods. The tumor presents itself as a large mass in the distal epiphysis, characterized by spicular outgrowths and a rugose external texture. Histologically, the afflicted humerus displayed a high degree of vascularity and exhibited an extensive bone resorption process involving the medullary and endosteal regions...

This review summarises our two decades of polychlorinated biphenyl (PCB) monitoring in different marine organisms along the eastern Adriatic Sea. The aim was to gain an insight into the trends of PCB distribution in order to evaluate the effectiveness of past and current legislation and suggest further action. Here we mainly focus on PCB levels in wild and farmed Mediterranean mussels, wild and farmed bluefin tuna, loggerhead sea turtles, common bottlenose dolphins, and small pelagic fish. The use of artificial intelligence and advanced statistics enabled an insight into the influence of various variables on the uptake of PCBs in the investigated organisms as well as into their mutual dependence...

The study of the brain by magnetic resonance imaging (MRI) allows to obtain detailed anatomical images, useful to describe specific encephalic structures and to analyze possible variabilities. It is widely used in clinical practice and is becoming increasingly used in veterinary medicine, even in exotic animals; however, despite its potential, its use in comparative neuroanatomy studies is still incipient. It is a technology that in recent years has significantly improved anatomical resolution, together with the fact that it is non-invasive and allows for systematic comparative analysis...

Globally and historically, Indigenous healthcare is efficacious, being rooted in Traditional Healing (TH) practices derived from cosmology and place-based knowledge and practiced on the land. Across Turtle Island, processes of environmental dispossession and colonial oppression have replaced TH practices with a colonial, hospital-based system found to cause added harm to Indigenous Peoples. Growing Indigenous health inequities are compounded by a mental health crisis, which begs reform of healthcare institutions...

The Chinese soft-shelled turtle ( Pelodiscus sinensis ) is an important freshwater aquaculture turtle due to its taste and nutritional and medicinal value. More ecological culturing modes, such as rice-turtle co-culture, should be developed to meet the ecological benefit demand. We compared growth, physiological parameters, and transcriptome data to detect the physiological responses and regulatory mechanisms of pond-cultured turtles as compared to co-cultured turtles. The co-cultured turtles grew slower than pond-cultured turtles...

The DKK family is a canonical small family of WNT antagonists. Though recent studies have suggested that the DKK gene family may be involved in sex differentiation in Pelodiscus sinensis , there are still a lot of things about the DKK gene family that we do not know. In this study, we used bioinformatics methods to identify members of the DKK gene family in P. sinensis and analyzed their phylogeny, covariance, gene structure, structural domains, promoter conserved sites, signal peptides, gonadal transcription factors, transcriptional profiles, and tissue expression profiles...

After hatching, sea turtles leave the nest and disperse into the ocean. Many years later, they return to their natal coastlines. The period between their leaving and their returning to natal areas, known as the "Lost Years", is poorly understood. Satellite tracking studies aimed at studying the "Lost Years" are challenging due to the small size and prolonged dispersal phases of young individuals. Here, we summarize preliminary findings about the performance of prototype microsatellite tags deployed over a three-year period on 160 neonate to small juvenile sea turtles from four species released in the North Atlantic Ocean...

Longer distance water delivery culverts pose obstacles such as deposited silt, stones, and dead trees. In this paper, a crawling robot is designed to mimic the joint structure of a turtle using bionic design principles. The mechanism and gait of the robot are analyzed. The kinematics model of the robot is established using the D-H method and analytical approach, while the dynamics model is established using Lagrange's method. Based on kinematics and dynamics analysis theory, compound cycloid and cubic polynomial motion trajectories for the robot foot are planned along with a crawling gait resembling that of a turtle's abdomen...

Lower respiratory tract disease associated with mycoplasmal infection was detected in a free-ranging bog turtle (Glyptemys muhlenbergii) from New Jersey, US. The presence of a mycoplasmal organism was confirmed by PCR and electron microscopy. Fluid-filled lungs were observed grossly, and there was proliferative pneumonia on histopathology. Respiratory disease caused by Mycoplasmopsis (Mycoplasma) spp. has been widely documented across animal taxa. In reptiles, these infections are predominantly implicated in upper respiratory tract disease (URTD)...

We examined the probability of past sea turtle nesting as a function of light intensity and patterns of temporal changes of light along nesting beaches in the Egyptian Red Sea. Beaches had a lower probability of past sea turtle nesting as light intensity increased. Light has been significantly increasing on mainland nesting beaches between 1992 and 2021 except for temporary declines. Island beaches historically had lower light pollution, but there was a sudden increase of light starting in 2014 that continued through 2021, except for the precipitous decline in 2020 during the Covid 19 pandemic...

Little is known about the behavioral and cognitive traits that best predict invasion success. Evidence is mounting that cognitive performance correlates with survival and fecundity, two pivotal factors for the successful establishment of invasive populations. We assessed the quantity discrimination ability of the globally invasive red-eared slider (Trachemys scripta elegans). We further compared it to that of the native stripe-necked turtle (Mauremys sinensis), which has been previously evaluated for its superior quantity discrimination ability...

The Virtual Access to STEM Careers (VASC) project is an intertwined classroom and virtual reality (VR) curricular program for third through fourth graders. Elementary school students learn about and take on the roles and responsibilities of STEM occupations through authentic, problem-based tasks with physical kits and immersive VR environments. This article reports on a round of curriculum and virtual environment development and in-classroom experimentation that was guided by preliminary results gathered from our initial VASC prototyping and testing...

Population declines of vertebrates are common, but rebuilding marine life may be possible. We assessed trends in sea turtle numbers globally, building 61 time series of abundance extending beyond 2015, representing monitoring in >1200 years. Increases were widespread with significant upward trends, no significant change, and significant downward trends in 28, 28, and 5 time series, respectively. For example, annual nest numbers increased between 1980 and 2018 from around 4,000 to 16,000 for green turtles at Aldabra (Seychelles, Indian Ocean) and between 2008 and 2020 from around 500 to 35,000 for loggerhead turtles in Sal (Cape Verde, north Atlantic)...

The pig-nosed turtle (Carettochelys insculpta) represents the only extant species within the Carettochelyidae family, is a unique Trionychia member fully adapted to aquatic life and currently facing endangerment. To enhance our understanding of this species and contribute to its conservation efforts, we employed high-fidelity (HiFi) and Hi-C sequencing technology to generate its genome assembly at the chromosome level. The assembly result spans 2.18 Gb, with a contig N50 of 126 Mb, encompassing 34 chromosomes that account for 99...

The pharmacokinetics of florfenicol (FFC) in green sea and hawksbill sea turtles were evaluated following intramuscular (i.m.) administration at two different dosages of 20 or 30 mg/kg body weight (b.w.). This study (longitudinal design) used 5 green sea and 5 hawksbill sea turtles for the two dosages. Blood samples were collected at assigned times up to 168 h. FFC plasma samples were analyzed using validated high-performance liquid chromatography equipped with diode array detection. The pharmacokinetic analysis was performed using a non-compartment approach...

BACKGROUND: Biological invasions are a leading cause of reductions in global biodiversity. Islands are particularly sensitive to invasions, which often result in cascading impacts throughout island communities. Wild pigs (Sus scrofa) are globally invasive and pose threats to numerous taxa and ecosystems, particularly for islands where they have contributed to declines of many endemic species. However, the impacts of wild pig diet on the flora and fauna remain understudied in many island systems...