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1.
Braz. j. biol ; 84: e249808, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345554

RESUMO

Abstract The sexing of species is an important tool for population management. In tortoises and turtles, sexing is usually done according to secondary characteristics, such as plastron morphology or phallus eversion techniques. In this paper, we present the phallus eversion method and compare its efficiency to other existing techniques. This new method aims at shortening the management time and reducing the physical aftereffects on the animals, fostering the clinical and reproductive management of Geoffroy's side-necked turtle (Phrynops geoffroanus) and related species. A sample of fifty individuals was taken in the central region of Piauí state, Northeastern Brazil. The proposed method consisted of moving the head from its resting position. The methods achieving a success rate higher than 80% were compared to each other as for the stimulation time required for phallus eversion. The method as here proposed achieved 100% efficiency in the sex determination of specimens with a linear carapace length between 10 and 34 cm. Also, when compared to the second most efficient method, it substantially reduced the time needed for managing the specimens (91%), avoiding possible sequelae in the individuals handled.


Resumo A sexagem das espécies é uma ferramenta importante para o manejo populacional. Em tartarugas, cágados e jabutis, a sexagem geralmente é feita de acordo com características secundárias, como morfologia do plastrão ou técnicas de eversão do falo. Neste artigo, apresentamos o método de eversão do falo e comparamos sua eficiência com outras técnicas existentes. Este novo método visa encurtar o tempo de manejo e reduzir os efeitos colaterais físicos nos animais, promovendo o manejo clínico e reprodutivo do cágado-de-barbicha (Phrynops geoffroanus) e espécies relacionadas. Uma amostra de cinquenta indivíduos foi coletada na região central do estado do Piauí, Nordeste do Brasil. O método proposto consiste em remover a cabeça de sua posição de repouso. Os métodos que obtiveram índice de sucesso superior a 80% foram comparados entre si quanto ao tempo de estimulação necessário para a eversão do falo. O método aqui proposto alcançou 100% de eficiência na determinação do sexo de espécimes com comprimento de carapaça linear entre 10 e 34 cm. Além disso, quando comparado ao segundo método mais eficiente, reduziu substancialmente o tempo necessário para o manejo dos espécimes (91%), evitando possíveis sequelas nos indivíduos manuseados.


Assuntos
Animais , Tartarugas , Brasil
2.
Artigo em Inglês | MEDLINE | ID: mdl-36257571

RESUMO

In aquatic organisms, ammonia is one of the major factors that affect energy levels when it exceeds its optimal concentration. Numerous studies have examined the effects of ammonia on aquatic animals, but its effect on metabolism is still unknown. The effect of ammonia on carbohydrates and lipid metabolism in the Chinese striped neck turtle (Mauremys sinensis) was investigated in this study by exposing the turtle to two different ammonia concentrations (A100: 1.53 mg L-1) and (A200: 2.98 mg L-1) for 24 and 48 h, respectively. Our results showed that the mRNA expression of adenosine monophosphate-activated protein kinase α1 (AMPKα1) significantly increased only in A100 at 24 h, whereas its activity increased in both ammonia-exposed groups. The two AMPK-regulated transcription factors responsible for carbohydrate metabolism also exhibited changes in ammonia-treated groups, as hepatocyte nuclear factor-4-alpha (HNF4α) increased and forkhead box protein O1 (FoxO1) decreased. The expression of phosphofructokinase (PFK) and glucose-6-phosphatase (G-6-PAS) was subsequently downregulated. In addition, transcription factors, carbohydrate-responsive element-binding protein (ChREBP), and sterol regulatory element-binding protein 1c (SREBP-1c), which are known to be involved in lipogenesis, were suppressed. These downstream genes include fatty acid synthase, stearoyl CoA desaturase, and acetyl-CoA carboxylase (FAS, SCD-1 and ACC). Moreover, the glucose content decreased, whereas the triglyceride content increased significantly in A200 at 24 h. We concluded that AMPK signaling inhibits gluconeogenesis and lipogenesis, and promotes glycolysis to meet energy demand under stressful conditions in M. sinensis.


Assuntos
Metabolismo dos Lipídeos , Tartarugas , Animais , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Tartarugas/metabolismo , Amônia/toxicidade , Amônia/metabolismo , Fígado/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Glucose/metabolismo , China
3.
Respir Physiol Neurobiol ; 307: 103978, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36252778

RESUMO

The effects of temperature on breathing pattern and oxygen consumption are being investigated in juvenile tortoises and compared to adults, in order to understand physiological adjustments of the respiratory system as related to body size, especially regarding the energetic expenditure associated with growth. We analyzed the breathing pattern and oxygen consumption of juvenile and adult red-footed tortoises (Chelonoidis carbonarius, Cryptodira: Testudinidae). The animals (N = 9; body mass ranging from 0.03 Kg to 2.5 Kg) were exposed to normoxic-normocarbic conditions using open respirometry in order to determine the breathing pattern and oxygen consumption in three different temperatures (15, 25, 35 °C). The obtained results showed intermittent breathing pattern in all tested temperatures in juveniles and adults. Tidal volume was not affected by changes in temperature, while breathing frequency increased significantly with increasing temperature, leading to a significant increment in minute ventilation between 15 and 35 °C. Mass specific oxygen consumption increased significantly with temperature and juveniles showed greater values when compared to adults. The alterations in the ventilatory response to temperature changes occurred in order to maintain the oxygen supply with increased metabolic activity. The differences between juveniles and adults in breathing frequency lead to juveniles needing a lower ventilation rate to perform gas exchange while extracting more oxygen. While these differences might be attributed to a greater metabolic expenditure during development, scaling effects on respiratory variables might be the main contributors to the found differences.


Assuntos
Tartarugas , Animais , Temperatura , Consumo de Oxigênio/fisiologia , Respiração , Oxigênio
4.
Sci Rep ; 12(1): 18151, 2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36316441

RESUMO

Biomechanically, sea turtles could be perceived as birds of the ocean as they glide and flap their forelimbs to produce the necessary forces required for locomotion, making sea turtles an interesting animal to study. However, being an endangered species makes studying the sea turtle's biomechanics a complex problem to solve, both technically and ethically, without causing disturbance. This work develops a novel, non-invasive procedure to develop full three-dimensional kinematics for wild sea turtles by filming the animals in Australia's Great Barrier Reef using underwater drones without disturbing them. We found that the wild animals had very different swimming patterns than previous studies on juveniles in captivity. Our findings show that the flipper goes through a closed-loop trajectory with extended sweeping of the flipper tip towards the centre of the carapace to create a clapping motion. We have named this the "sweep stroke" and in contrast to previously described four-stage models, it creates a five-stage cycle swimming locomotion model. The model presented here could lead to a better comprehension of the sea turtle propulsion methods and their fluid-structure interaction.


Assuntos
Tartarugas , Animais , Natação , Fenômenos Biomecânicos , Animais Selvagens , Locomoção
5.
Arch Microbiol ; 204(11): 682, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36316591

RESUMO

This study was conducted during the 2018 nesting season at the Sugözü Beaches (Adana-Turkey) and Göksu Delta (Mersin-Turkey). Egg samples (n = 63) from loggerhead and green turtle nests (n = 43) were collected. Isolated bacteria were initially identified by phenotypic methods and then by MALDI-TOF MS. The bacterial mass spectra were analyzed using Principal Component Analysis. Bacterial isolation was performed for 55 isolates belonging to 12 genera from two major nesting sites. In Sugözü Beaches 62.2% of the bacteria species belonged to Enterobacteriaceae and in Göksu Delta 44.4% of the bacteria species belonged to Morganellaceae. Klebsiella oxytoca and Staphylococcus haemolyticus had not previously been detected in any sea turtle nests. This is the first MALDI-TOF MS study conducted for determination of bacterial variability in loggerhead turtle eggs in Turkey and serves as a reference study for the assessment of bacterial threat in sea turtle nests, enabling the establishment of suitable conservation measures and treatment processes for both sea turtles and nesting sites.


Assuntos
Tartarugas , Animais , Tartarugas/microbiologia , Comportamento de Nidação , Turquia , Bactérias/genética , Estações do Ano
6.
PLoS One ; 17(11): e0269346, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36322564

RESUMO

The concentrations of trace elements including As, Zn, Cu, Se, Pb, Hg and Cd, were determined in the blood of nesting Kemp's ridley turtles (Lepidochelys kempii) at Rancho Nuevo sanctuary, Tamaulipas, Mexico during 2018-2020. The sequential concentrations analyzed were Zn> Se> Cu> As> Pb; while Cd and Hg concentrations were below the limits of detection (0.01 µg g-1). No significant differences were observed between the concentrations of trace elements (p> 0.05) by year, except Se levels, possibly resulting from recorded seasonal differences in turtle size. No relationships among turtle size vs elements concentration were observed. In conclusion, essential and toxic trace elements concentrations in the blood of nesting Kemp's ridley turtles may be a reflex of the ecosystem in which the turtles develop, that is, with low bioavailability of elements observed in the trophic webs in the Gulf of Mexico.


Assuntos
Mercúrio , Oligoelementos , Tartarugas , Animais , Ecossistema , Cádmio , Chumbo , México
7.
BMC Ecol Evol ; 22(1): 131, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344915

RESUMO

BACKGROUND: Hotspots of intraspecific genetic diversity represent invaluable resources for species to cope with environmental changes, and their identification is increasingly recognized as a major goal of conservation ecology research. However, even for iconic and endangered species, conservation strategies are often planned without thorough information on the geographic patterns of genetic variation. Here, we investigated the spatial patterns of genetic variation of the endangered Hermann's tortoise Testudo hermanni in the Italian Peninsula by genotyping 174 individuals at 7 microsatellite loci, with the aim to contribute to planning effective conservation strategies. RESULTS: Ordination-based and Bayesian clustering analyses consistently identified three main genetic clusters, one spread in the central and northern part of the peninsula, and two restricted to southern Italy and Sicily, respectively. The highest levels of genetic diversity were found in populations of the southern cluster and, in particular, at the northern edges of its distribution (He > 0.6, Ar > 2.8 ), that correspond to areas of putative secondary contact and admixture between distinct lineages. Our results clearly identify a hotspot of genetic diversity for the Hermann's tortoise in southern Italy. CONCLUSION: We inferred the evolutionary history and the spatial patterns of genetic variation of the Hermann's tortoise in the Italian Peninsula. We identified three main genetic clusters along the peninsula and a hotspot of intraspecific diversity in southern Italy. Our results underline the urgent need for conservation actions to warrant the long-term persistence of viable tortoise populations in this area. Furthrmore, these data add further evidence to the role of southern Italy as a biodiversity hotspot for temperate fauna, claiming for higher consideration of this area in large scale conservation programs.


Assuntos
Tartarugas , Humanos , Masculino , Animais , Tartarugas/genética , Teorema de Bayes , Repetições de Microssatélites/genética , Variação Genética/genética , Sicília
8.
Zoonoses Public Health ; 69(8): 925-937, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36345968

RESUMO

Non-typhoidal Salmonella cause an estimated 1.4 million human illnesses, 26,000 hospitalizations and 400 deaths annually in the United States. Approximately 11% of these infections are attributed to animal contact. Reptiles and amphibians are known sources of salmonellosis; young children (aged <5 years) are disproportionately affected by reptile- and amphibian-associated salmonellosis (RAAS) outbreaks. We describe multistate RAAS outbreaks to characterize illnesses and inform prevention efforts. RAAS outbreaks were defined as ≥2 culture-confirmed human Salmonella infections with similar pulsed-field gel electrophoresis patterns and epidemiologic, laboratory or traceback evidence linking them to a common reptile/amphibian exposure. Data sources included the Animal Contact Outbreak Surveillance System; CDC Outbreak Response and Prevention Branch's outbreak management database; PulseNet, the national molecular subtyping network for foodborne disease surveillance in the United States; and the National Antimicrobial Resistance Monitoring System. Twenty-six RAAS outbreaks were reported during 2009-2018, resulting in 1465 illnesses and 306 hospitalizations. The outbreaks were associated with turtles (19), lizards (5), snakes (1) and frogs (1). Sixteen (61.5%) outbreaks were linked to small turtles (<4 inches), resulting in 914 illnesses. Forty-nine percent of outbreak-associated patients were aged <5 years. Of 362 patients/caregivers interviewed, 111 (30.7%) were aware that reptiles/amphibians can carry Salmonella. Among 267 patient isolates with antimicrobial susceptibility information, 20 (7.5%) were non-susceptible to ≥1 antibiotic used to treat human salmonellosis. RAAS outbreaks result in considerable morbidity, particularly among young children. Illnesses linked to small turtles are preventable through education, targeted outreach to caregivers and paediatricians, and when appropriate, enforcement. Historically, individual states and jurisdictions have enforced existing or promulgated new authorities to address outbreaks. Preventing future RAAS outbreaks requires addressing challenges related to the illegal sale/distribution of small turtles; and for legal reptile sales, providing information on RAAS risk to consumers at point of sale to support informed pet ownership decisions.


Assuntos
Anti-Infecciosos , Lagartos , Intoxicação Alimentar por Salmonella , Infecções por Salmonella , Tartarugas , Humanos , Estados Unidos/epidemiologia , Animais , Infecções por Salmonella/epidemiologia , Intoxicação Alimentar por Salmonella/epidemiologia , Intoxicação Alimentar por Salmonella/veterinária , Salmonella , Surtos de Doenças , Anfíbios
9.
J Environ Manage ; 324: 116408, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36352731

RESUMO

Tortuguero, Costa Rica is considered the second largest green turtle (Chelonia mydas) rookery in the world. By 1950, Tortuguero was one of the sites with the greatest take of green turtles in the Caribbean. Currently, Tortuguero is a worldwide example for ecotourism-based on sea turtle conservation. However, illegal take of nesting turtles still occurs. We aimed to describe the illegal take at Tortuguero, estimating the minimum number of sea turtles taken using data collected during daily and weekly track surveys from 2005 to 2021. Additionally, we conducted 12 semi-structured interviews with key informants to obtain a better understanding of this activity. We documented 735 nesting turtles illegally taken at Tortuguero, being the green turtle the most affected species; these findings were also supported by our interviewees. Respondents stated that in Tortuguero the take of sea turtles has always occurred and traditions regarding sea turtle meat consumption are still present, even though it is considered shameful in the village. However, our interviewees affirmed that most of the sea turtles taken are traded to other locations away from Tortuguero. Our findings represent the minimum of illegal take (documented only at the beach), as not all the sea turtles taken were observed. Finally, despite long-standing conservation efforts carried out in Tortuguero, further changes in the National Park's management plans are needed, including more personnel and increased law enforcement. This may be necessary to reduce the impact on the Tortuguero green turtle nesting population in the near future.


Assuntos
Tartarugas , Animais , Região do Caribe , Costa Rica/epidemiologia , Comportamento de Nidação , Conservação dos Recursos Naturais , Crime
10.
Sci Rep ; 12(1): 18322, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36396968

RESUMO

Marine turtles were common in the subtropical Upper Cretaceous epi-continental seas that once washed the coasts of the ancient European archipelago. But unlike its contemporaneous faunas from North America, in Europe no taxon surpassed the 1.5 m shell-length. Here, the remains of a new large marine turtle, Leviathanochelys aenigmatica gen. et sp. nov., from the Middle Campanian of the Southern Pyrenees are described. Anatomical and histological evidence concur in identifying the specimen as a basal chelonioid. The new taxon autapomorphically differs from other marine turtles by possessing an additional process on the anteromedial side of the pelvis, and an acetabulum directed strongly ventrally. Based on the pelvis size, it is likely that Leviathanochelys was as large as Archelon, thus becoming one of the largest marine turtles found to ever exist. The large body size of the new taxon could have evolved as a response to the unique habitat conditions of the European Cretaceous archipelago seas. The presence of the accessory pubic process further suggests the occurrence of an additional insertion point of the Musculus rectus abdominis, which together with the paleohistologic evidences support the hypothesis that the new taxon had an open marine pelagic lifestyle.


Assuntos
Tartarugas , Animais , Tartarugas/anatomia & histologia , Fósseis , Répteis , Europa (Continente) , América do Norte
11.
Vet Ital ; 58(1): 25-34, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36398674

RESUMO

Testudo hermanni is included as near­threatened in the Red List of the International Union for Conservation of Nature, while T. hermanni hermanni is considered endangered in the Italian Red List. Appropriate management of smuggled or seized wild individuals is recommended before their reintroduction into the wild. Accordingly, a health monitoring study was carried out. During 2014­2016, 133 oral swabs and 121 cloacal swabs were collected from a total of approximately 180 free­ranging and rescued T. hermanni hermanni from eight different Italian regions to investigate the presence of DNA of Testudinid alphaherpesvirus (TeAHV), Chlamydia spp. and Mycoplasma spp. in the oral cavity, and Salmonella spp. isolates in the cloaca. Mycoplasma spp. was detected in 52 out of 87 (59.77%) of rescued and in 1 out of 46 free­ranging (2.17%) individuals; 33 out of 53 (62.26%) Mycoplasma spp. positive samples were typed as M. agassizii by PCR. Salmonella spp. was isolated from 45 out of 121 (37.19%) cloacal swabs, typed into 14 serovars, and characterized for complete antimicrobial susceptibility. A significantly different distribution of Salmonella spp. isolates was found in 2016 in comparison with 2014 and 2015, without any difference between free­ranging and rescued tortoises. All the tested tortoises were negative for TeAHV and Chlamydia spp. These results are considered a baseline information critical to monitor the dynamics of these microorganisms in free­ranging and rescued populations of T. h. hermanni, and to correctly approach the management of rescued animals and possible relocation programs.


Assuntos
Chlamydia , Mycoplasma , Tartarugas , Animais , Salmonella , Itália
12.
Dis Aquat Organ ; 152: 61-71, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36394141

RESUMO

Despite being the most abundant sea turtle in the world, the olive ridley turtle Lepidochelys olivacea is classified as Vulnerable by the IUCN. There is evidence of congenital malformations in hatchlings, and the associated causes are multifactorial, with both genetic and environmental sources. Santuario Playa Ceuta (SPC) is a sanctuary for the olive ridley, located at the northernmost region of its nesting range in the Mexican Pacific. The objective of this study was to identify and quantify the prevalence and severity of congenital malformations in olive ridley embryos/hatchlings in SPC during the 2017 nesting season. We collected 62907 eggs from 643 relocated nests that were moved to a hatchery, of which 4242 eggs with obvious development did not hatch and were analyzed for this study. Hatching success was 53.9%, with 22.5% of nests (n = 145) and 0.54% of eggs (n = 344) showing embryos or hatchlings with malformations. The nest severity index was 2.4 (range: 1-10) malformed embryos or hatchlings per nest, and the organism severity index was 1.4 (range: 1-7) malformations per malformed embryo or hatchling. Leucism was the most prevalent malformation (34.4%; 170/494 total observed), with the craniofacial region showing the greatest diversity of malformations (17/35 types). Given the geographical position of SPC, extreme environmental conditions (e.g. cold, heat, and dryness) could be one of the main causes of teratogenesis in this species. However, more studies are needed regarding the presence of contaminants, genetic factors, health assessments of nesting females, and malformation rates of nests that remain in situ versus those that are relocated.


Assuntos
Tartarugas , Feminino , Animais , México/epidemiologia
13.
Proc Biol Sci ; 289(1987): 20221947, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36382514

RESUMO

The late Quaternary is characterized by the extinction of many terrestrial megafauna, which included tortoises (Family: Testudinidae). However, limited information is available on how extinction shaped the phenotype of surviving taxa. Here, based on a global dataset of straight carapace length, we investigate the temporal variation, spatial distribution and evolution of tortoise body size over the past 23 million years, thereby capturing the effects of Quaternary extinctions in this clade. We found a significant change in body size distribution characterized by a reduction of both mean body size and maximum body size of extant tortoises relative to fossil taxa. This reduction of body size occurred earlier in mainland (Early Pleistocene 2.588-0.781 Ma) than in island tortoises (Late Pleistocene/Holocene 0.126-0 Ma). Despite contrasting body size patterns between fossil and extant taxa on a spatial scale, tortoise body size showed limited variation over time until this decline. Body size is a fundamental functional trait determining many aspects of species ecologies, with large tortoises playing key roles as ecosystem engineers. As such, the transition from larger sized to smaller sized classes indicated by our findings likely resulted in the homogenization of tortoises' ecological functions and diminished the role of tortoises in structuring the vegetation community.


Assuntos
Tartarugas , Animais , Tartarugas/anatomia & histologia , Ecossistema , Tamanho Corporal , Fósseis , Extinção Biológica
14.
PLoS One ; 17(10): e0275088, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36288397

RESUMO

Current understanding of sea turtle nesting, hatching, and emergence events has been largely limited to observable events on the surface of the sand, though recent approaches using audio or visual equipment have allowed scientists to better understand some underground nest phenomena. We used a technology-based approach to define motion-related Caretta caretta hatching and emergence nest events. We describe a novel low-cost, accelerometer-based system called TurtleSense that can detect movement and temperature within sea turtle nests remotely. TurtleSense is successfully able to specifically detect motion within sea turtle nests over the entire course of incubation. This system allows for the identification of infertile nests and the detection of four predictable sequential developmental activity patterns in viable nests, including a hatch and posthatch period, the timing of which can be used to tightly predict hatchling emergence events almost to the day. TurtleSense provides a much better understanding about what is happening in the nest before emergence and allows for the generation of a theory of the mechanism that triggers mass emergence. Our results suggest that motion plays a large role in hatchling communication and that the timing of emergence events may be related to the cessation of movement within the nest. Current management of sea turtle nesting events is primarily driven by counting the number of days since the nest was laid, with further safeguards placed at the nest upon subsequent visual observation of depression or emergence events. Use of TurtleSense technology can impact nest management and conservation efforts, allowing organizations to use this motion data to more tightly predict emergence dates for sea turtle hatchlings and to use viability data to inform nest management decisions.


Assuntos
Tartarugas , Animais , Areia , Temperatura , Comportamento de Nidação
16.
Dev Biol ; 492: 101-110, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36220348

RESUMO

The forkhead transcription factor Foxl2 plays a major role in ovarian development and function in mice and fish, and acts as a female sex-determining gene in goat. Its functional role in the sex determination and gonadal differentiation has not yet been investigated in reptiles. Here, we characterized Foxl2 gene in Chinese soft-shelled turtle Pelodiscus sinensis, exhibiting ZZ/ZW sex chromosomes. Foxl2 exhibited a female-specific embryonic expression pattern throughout the critical sex determination periods in P. sinensis. The expression of Foxl2 was induced at early stage in ZZ embryonic gonads that were feminized by estrogen treatment. Most importantly, Foxl2 knockdown in ZW embryos by RNA interference resulted in female-to-male sex reversal, characterized by obvious masculinization of gonads, significant up-regulation of testicular markers Dmrt1 and Sox9, and remarkable down-regulation of ovarian regulator Cyp19a1. Conversely, gain-of-function study showed that overexpression of Foxl2 in ZZ embryos led to largely feminized genetic males, production of Cyp19a1, and a decline in Dmrt1 and Sox9. These findings demonstrate that Foxl2 is both necessary and sufficient to initiate ovarian differentiation in P. sinensis, thereby acting as a key upstream regulator of the female pathway in a reptilian species.


Assuntos
Proteína Forkhead Box L2 , Processos de Determinação Sexual , Tartarugas , Animais , Feminino , Masculino , China , Proteína Forkhead Box L2/genética , Processos de Determinação Sexual/genética , Diferenciação Sexual/genética , Tartarugas/genética
17.
Nature ; 610(7931): 283-289, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36224418

RESUMO

The current proliferation of mobile robots spans ecological monitoring, warehouse management and extreme environment exploration, to an individual consumer's home1-4. This expanding frontier of applications requires robots to transit multiple environments, a substantial challenge that traditional robot design strategies have not effectively addressed5,6. For example, biomimetic design-copying an animal's morphology, propulsion mechanism and gait-constitutes one approach, but it loses the benefits of engineered materials and mechanisms that can be exploited to surpass animal performance7,8. Other approaches add a unique propulsive mechanism for each environment to the same robot body, which can result in energy-inefficient designs9-11. Overall, predominant robot design strategies favour immutable structures and behaviours, resulting in systems incapable of specializing across environments12,13. Here, to achieve specialized multi-environment locomotion through terrestrial, aquatic and the in-between transition zones, we implemented 'adaptive morphogenesis', a design strategy in which adaptive robot morphology and behaviours are realized through unified structural and actuation systems. Taking inspiration from terrestrial and aquatic turtles, we built a robot that fuses traditional rigid components and soft materials to radically augment the shape of its limbs and shift its gaits for multi-environment locomotion. The interplay of gait, limb shape and the environmental medium revealed vital parameters that govern the robot's cost of transport. The results attest that adaptive morphogenesis is a powerful method to enhance the efficiency of mobile robots encountering unstructured, changing environments.


Assuntos
Biomimética , Meio Ambiente , Desenho de Equipamento , Robótica , Animais , Biomimética/instrumentação , Biomimética/métodos , Locomoção , Robótica/instrumentação , Robótica/métodos , Tartarugas/fisiologia
18.
PLoS One ; 17(10): e0276382, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36256654

RESUMO

The recent commercialization of unoccupied aerial vehicles (UAVs) has facilitated their incorporation into a variety of ecological studies. While UAVs are able to provide accurate visual data of marine species from an aerial perspective, these devices have some limitations that make measuring marine animals below the surface challenging. Many marine organisms are often visible from the air, but are deeper in the water column, and current methods cannot measure animals below the surface. Here, we developed and tested a stereo-video camera (SVC) system that was mounted onto a commercially-available UAV. We used the SVC-UAV to conduct remote body-size measurements for two marine species: the green sea turtle (Chelonia mydas) and the nurse shark (Ginglymostoma cirratum). When comparing SVC measurements to those taken by hand, the SVC-UAV had a mean absolute error (MAE) of 4.44 cm (n = 6; mean percent error (MPE) = 10.6%) for green sea turtles and 7.16 cm absolute error (n = 1; PE = 3.6%) for the nurse shark. Using a linear model, we estimated the slope of the SVC versus hand measurements for green sea turtles to be 1.085 (±0.099 SE), and accounting for the standard error, a measurement bias was not apparent. Using model selection, based on a global model predicting MAE from animal distance to the SVC and body size, the top ranked model was the intercept-only model. This indicates that neither animal distance nor body size strongly influenced measurement error. Incorporating SVC systems into UAVs can allow for relatively accurate measurements of near surface-dwelling marine species. To our knowledge, there is no other stand-alone SVC for UAVs available that offers similar accuracy and utility.


Assuntos
Tubarões , Tartarugas , Animais , Organismos Aquáticos , Água
19.
Vet Parasitol Reg Stud Reports ; 35: 100782, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36184111

RESUMO

Pentastomes are crustacean endoparasites in the lungs of herpetofauna and rarely mammals and birds. To date, the only pentastomes reported in chelonians, all aquatic turtles, are Diesingia megastomum from Brazil and Pelonia africana from South Africa. In March 2021, 185 juvenile tortoises (Chelonoidis niger) were confiscated after an attempted illegal exportation from the Galápagos. It is believed the tortoises were removed from nests on Santa Cruz Island. The young tortoises were individually wrapped in plastic and at seizure ten were dead and another 25 tortoises subsequently died. One of the tortoises, estimated to be 3 months old, had 11 pentastomes in the lungs. The pentastomes were identified as a Raillietiella sp. based on morphology. The specimens had a claviform body that tapers into a bifid tail, a 165.3 µm × 92.1 µm buccal cadre, and sharp tipped anterior and posterior hooks with the posterior hooks being larger than the anterior. The males have smooth copulatory spicules with a rounded, smooth base. All females were gravid. Molecular analysis confirmed that the parasites were a Raillietiella sp. Based on the COI gene, it was most similar (82.7% identical) to an undescribed Raillietiella species from a Caribbean anole (Anolis cristatellus) found in Florida followed by R. hebitihamata (81%), R. indica (80.7%), and R. orientalis (78.8-80.7%). Based on the 18S rRNA gene sequence (1799 bp), it was most similar (99.3% identical) to two undescribed Raillietiella species followed by R. aegypti from a berber skink (Eumeces schneideri) from Saudia Arabia. Phylogenetically, with both molecular targets, the Raillietiella sp. from the Galápagos tortoise grouped with other Raillietiella spp. and was basal within the group. Currently, the origin of this parasite (native to Galápagos or introduced) and the life cycle are unknown. Because some pentastome species, especially when in aberrant hosts, can be pathogenic, additional studies of parasites in native and introduced reptile and amphibian species in the Galápagos are needed to better understand the risk this parasite poses to Galápagos tortoises.


Assuntos
Artrópodes , Lagartos , Pentastomídeos , Tartarugas , Animais , Feminino , Masculino , Mamíferos , Níger , Plásticos , Tartarugas/genética , Tartarugas/parasitologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-36191476

RESUMO

Given their threatened status, there is considerable interest in establishing monitoring techniques that can be used to evaluate the health of sea turtles in the wild. The present study represents a methodological contribution towards field-scale metabolomic assessment of sea turtles, by exploring differences in blood biochemistry associated with site characteristics and capture technique. We compared the metabolome of blood from animals at three locations (two coastal and one reefal), collected from turtles that were either resting or active, and sampled across multiple seasons at one location. Our results show clear differences in the metabolome of turtles from the three locations, some of which are likely attributable to differences in diet or forage quality and others which may reflect differences in other factors (e.g., occurrence of land-based contaminants or other biotic and/or abiotic stressors) between coastal and reefal sites. Our analysis also revealed the influence of capture technique on metabolite profiles, with numerous markers of physical exertion in animals captured while active that were absent in turtles sampled while resting. We observed a modest potential for temporal differences in the metabolome, but controlling for sampling time did not change the overall conclusions of our study. This suggests that temporal differences in the metabolome warrant consideration when designing studies to evaluate the status of sea turtles in the wild, but that site characteristics and capture technique are bigger drivers. However, sample size for this comparison was relatively small and further investigation of seasonal differences in the metabolome are warranted. Research exploring each of these factors more closely will further contribute towards achieving robust metabolomics analysis of sea turtles across large spatial and temporal scales.


Assuntos
Tartarugas , Animais , Tartarugas/metabolismo , Dieta , Metaboloma
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