Turtle Research Articles

Alien Freshwater Turtles in Greece: Citizen Science Reveals the Hydra-Headed Issue of the Pet Turtle Trade

Citizen science is emerging as a powerful tool for the early detection of biological invasions. The exotic pet trade has been deemed as the most significant cause of establishment for reptiles, and among them, turtles have the highest number of introduction events. In Europe, at least 13 species of alien freshwater turtles have been recorded in the wild. In Greece, only two species of alien turtles have been reported, namely the American pond slider Trachemys scripta and the Florida cooter Pseudemys floridana. In this study, we provide an updated checklist of the alien freshwater turtles recorded in Greece, using citizen science, personal observations, and literature. Our results provide the first records for the country of five species, namely the Florida red-bellied cooter Pseudemys nelsoni, the Eastern river cooter Pseudemys concinna, the Chinese stripe-necked turtle Mauremys sinensis, the Chinese soft-shelled turtle Pelodiscus sinensis, and the Common snapping turtle Chelydra serpentina and new localities for T. scripta. Similar to the myth of the Lernaean Hydra (i.e., for every head chopped off, more would regrow), the pet turtle trade has been proven to have multiple heads.

Ineffectiveness of plastic mesh for protecting artificial freshwater turtle nests from red fox (Vulpes vulpes) predation

AbstractInvasive mammalian predators are efficient at driving native animal declines. The red fox (Vulpes vulpes) kills millions of endemic reptiles in Australia each year. In areas of south‐eastern Australia, the eastern long‐necked turtle (Chelodina longicollis) and Murray River turtle (Emydura macquarii) have declined by more than 50%. High rates of nest predation by foxes limit the recruitment of young turtles in these populations, but previous methods of fox control have been ineffective at protecting turtle nests. Here, we tested the effectiveness of plastic mesh for protecting artificial turtle nests from predation by foxes, in the mid‐Murray catchment, Victoria. We also tested whether protecting a large number of artificial nests in a given area encourages foxes to give up foraging following predictions from giving‐up density theory. We made a series of plots, each containing 32 artificial turtle nests. In each plot, we covered a percentage (0%, 25%, 50%, 81% or 100%) of the nests with either 1 or 2 sheets of plastic mesh. We used remote cameras to photograph and identify any predator that attacked nests in the plots. The cameras also allowed us to estimate the amount of time a fox was visible on each plot, as a metric of how much effort foxes expended on protected nests. Nest survival rate was not increased by either 1 or 2 sheets of mesh, and increasing the number of protected nests on a plot did not reveal a giving‐up density (GUD) value for fox foraging behaviour. Our study demonstrates that plastic mesh is not effective for protecting artificial turtle nests from foxes in this region.

Activity of a freshwater turtle varies across a latitudinal gradient: Implications for the success of assisted colonisation

Abstract The value of assisted colonisation as a response to climate change can only be realised if focal species are well suited to their new habitats. For ectotherms, new habitats must offer microclimates that promote crucial behaviours such as thermoregulation and foraging. The Western swamp turtle Pseudemydura umbrina, a Critically Endangered species from south‐western Australia, serves as a global case‐study of assisted colonisation in action. Initial trials where juvenile P. umbrina were released into wetter and cooler climates found that individuals spent considerable time at body temperatures that apparently limited their growth. Using high‐resolution biologging data (temperature and depth), here we tested if turtle activity is thermally constrained in cooler latitudes by releasing 48 juveniles into seasonal swamps at three sites. One site was core natural habitat, and the other sites were wetlands 380 km apart that offered either warmer or cooler microclimates. Generalised additive mixed models were used to evaluate behaviours and time spent at optimal temperatures for approximately 1 month following release, and growth rates were measured and analysed after release until the end of the hydroperiod 4–5 months later. We found that turtles released into the most poleward (southern) wetland spent significantly less time active and basking and grew significantly less compared to turtles released further north. When analysed together, behavioural and growth datasets showed that activity was positively correlated with growth rates. We conclude that poor growth of turtles in the southern wetland was likely a result of lower body temperatures, stemming from a reduced ability to thermoregulate in water. Consequently, for assisted colonisation of juvenile P. umbrina to be successful, recipient wetlands must offer aquatic microclimates that are sufficiently warm to promote foraging activity that leads to growth, and ultimately to maturation. Read the free Plain Language Summary for this article on the Journal blog.

Low coverage sequencing provides insights into the key features of the nuclear and mitochondrial genomes of the Alligator Snapping Turtle Macrochelys temminckii

The alligator snapping turtle Macrochelys temminckii is a culturally, ecologically, and evolutionary relevant species of conservation concern. In this study, we conducted a genome survey of M. temminckii. Using a low-coverage short read sequencing strategy, this study estimated the genome size, repetitive genome content, annotated and quantified repetitive elements, assembled the 45S rRNA DNA operon, and characterized in detail the mitochondrial genome of M. temminckii. Using a k-mer strategy, the estimated haploid genome size varied between 3.77 and 3.19 Gbp, which is within the range previously reported for other representatives of the family Chelydridae. Repetitive genome content estimates using different k-mers (21 to 51) indicated that more than 75 % of the genome of M. temminckii comprised repetitive elements. Taking into account only annotated repetitive elements, the most common repetitive elements were classified as Class I - Long Interspersed Nuclear Element (LINE) which were more abundant than Class I – Penelope and Class I - Long Terminal Repeat (LTR) Ty3 mobile elements. Less abundant repeat element families in the nuclear genome of M. temminckii included Class I - DIRS mobile elements and Satellite DNA. The nuclear ribosomal operon was partially assembled into three contigs, one encoding the complete ssrRNA gene, a second encoding the complete 5.8S rRNA gene, and a third comprising the full lsrRNA gene. The AT-rich complete mitochondrial genome was 16,570 bp long. These new genomic resources are of utmost importance to aid in the development of conservation plans for this iconic freshwater turtle.

First record of the Vulnerable Malayan Flat-shelled Turtle, Notochelys platynota (Gray 1834) (Reptilia, Testudines, Geoemydidae), in Belitung, Indonesia

The Malayan Flat-shelled Turtle, Notochelys platynota (Gray 1834), is a freshwater turtle endemic across Southeast Asia and is categorized as Vulnerable according to the IUCN Red list. We report the first record of this species from Belitung, a remote Island in Indonesia, based on photographs. The new record is approximately 150 km to the east of the nearest locality on Bangka Island, Indonesia. This species was obtained in upstream, slow-flowing waters in forested hills 75 m above sea level.

Effects of landscape structure and land use on turtle communities across the eastern United States

Landscape context is integral to population ecology, affecting a range of life history parameters, yet very little is known about how landscape structure influences many taxa. We sampled wetlands at 531 sites across 16 states in the eastern U.S. to examine the influence of landscape heterogeneity and anthropogenic land use on the relative abundance of freshwater turtles, one of the most endangered vertebrate clades in the world. Specifically, we aimed to understand how two components of landscape structure — compositional heterogeneity (wetland diversity) and configurational heterogeneity (wetland aggregation) — influence turtles with varying life history traits. Our results suggest that wetland configuration can modulate the relationship between relative abundance and anthropogenic land use. For example, spotted turtle (Clemmys guttata) was negatively associated with hay/pasture cover when wetlands were less aggregated, but this relationship subsided as aggregation increased. Notably, the way wetland aggregation modulated land use relationships varied across species. These results suggest that some anthropogenic cover types are not strictly positive or negative for certain species, but are instead context-dependent. Relative abundance also generally increased with higher wetland diversity, indicating the potential importance of landscape supplementation for turtles. We report a range of responses to roads that did not strictly correspond with well-established predictions related to body size and terrestrial activity patterns, including positive associations for certain species. Overall, our study supports the use of context-driven approaches to land use-related conservation and management decisions rather than blanket prescriptions, and further emphasizes that effective conservation of freshwater systems requires a landscape-level perspective.

Using Plasma Vitellogenin in Loggerhead Sea Turtles to Assess Reproductive Maturation and Estrogen-Like Contaminant Exposure.

Vitellogenin (VTG), an egg yolk precursor, is abnormally produced by male and juvenile oviparous species after exposure to estrogens. Plasma VTG in loggerhead sea turtles (Caretta caretta) helped us understand their reproductive maturation and investigate it as a biomarker of contaminant exposure. The presence of VTG was screened in plasma from 404 loggerheads from the northwestern Atlantic Ocean using a freshwater turtle antibody in western blots. The concentrations of VTG were semiquantified using band intensities calibrated to results from a loggerhead antibody enzyme-linked immunoassay. The detection and concentrations of VTG were in (from highest to lowest): nesting females, in-water adult females, subadult females, smaller females, unknown sex, and males. Loggerheads from this region begin vitellogenesis at ≅77 cm straight carapace length. We classified VTG expression as abnormal in nine male or juvenile turtles. Organochlorine contaminant (OC) concentrations were measured in blood and/or fat biopsies of some turtles. One abnormal VTG female had the second highest fat polychlorinated biphenyl (PCB) and 4,4'-dichlorodiphenyldichloroethylene concentrations compared among 43 VTG-negative juveniles. The nine VTG-abnormal turtles had average blood PCB concentrations 8.5% higher, but not significantly different, than 46 VTG-negative juveniles (p = 0.453). In turtles less than 77 cm, blood PCB concentrations were significantly, but weakly, correlated with semiquantified VTG concentrations (tau = 0.1, p = 0.004). Greater blood OC concentrations were found in adult females than in males, which motivated the creation of a conceptual model of OC, VTG, and hormone concentrations across a reproductive cycle. A decision tree is also provided incorporating VTG as a sexing tool. Abnormal VTG expression cannot conclusively be linked to endocrine disruption caused by these OC concentrations. Studies should further investigate causes of abnormal VTG expression in wild sea turtles. Environ Toxicol Chem 2023;42:1309-1325. © 2023 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Differences in locomotor performances between two sympatric species of freshwater turtles

Differences in locomotor performances between two sympatric species of freshwater turtles

Too cold is better than too hot: Preferred temperatures and basking behaviour in a tropical freshwater turtle

AbstractThermoregulation is critical to the survival of animals. Tropical environments can be particularly thermally challenging as they reach very high, even lethal, temperatures. The thermoregulatory responses of tropical freshwater turtles to these challenges are poorly known. One common thermoregulatory behaviour is diurnal basking, which, for many species, facilitates heat gain. Recently, however, a north‐eastern Australian population of Krefft's river turtles (Emydura macquarii krefftii) has been observed basking nocturnally, possibly to allow cooling. To test this, we determined the thermal preference (central 50% of temperatures selected) of E. m. krefftii in an aquatic thermal gradient in the laboratory. We then conducted a manipulative experiment to test the effects of water temperatures, both lower and higher than preferred temperature, on diurnal and nocturnal basking. The preferred temperature range fell between 25.3°C (±SD: 1.5) and 27.6°C (±1.4) during the day, and 25.3°C (±2.4) and 26.8°C (±2.5) at night. Based on this, we exposed turtles to three 24 h water temperature treatments (‘cool’ [23°C], ‘preferred’ [26°C] and ‘warm’ [29°C]) while air temperature remained constant at 26°C. Turtles basked more frequently and for longer periods during both the day and night when water temperatures were above their preferred range (the ‘warm’ treatment). This population frequently encounters aquatic temperatures above the preferred thermal range, and our results support the hypothesis that nocturnal basking is a mechanism for escaping unfavourably warm water. Targeted field studies would be a valuable next step in understanding the seasonal scope of this behaviour in a natural environment.

Low production of mitochondrial reactive oxygen species after anoxia and reoxygenation in turtle hearts.

Extremely anoxia-tolerant animals, such as freshwater turtles, survive anoxia and reoxygenation without sustaining tissue damage to their hearts. In contrast, for mammals, the ischemia-reperfusion (IR) injury that leads to tissue damage during a heart attack is initiated by a burst of superoxide (O2·-) production from the mitochondrial respiratory chain upon reperfusion of ischemic tissue. Whether turtles avoid oxidative tissue damage because of an absence of mitochondrial superoxide production upon reoxygenation, or because the turtle heart is particularly protected against this damage, is unclear. Here, we investigated whether there was an increase in mitochondrial O2·- production upon the reoxygenation of anoxic red-eared slider turtle hearts in vivo and in vitro. This was done by measuring the production of H2O2, the dismutation product of O2·-, using the mitochondria-targeted mass-spectrometric probe in vivo MitoB, while in parallel assessing changes in the metabolites driving mitochondrial O2·- production, succinate, ATP and ADP levels during anoxia, and H2O2 consumption and production rates of isolated heart mitochondria. We found that there was no excess production of in vivo H2O2 during 1 h of reoxygenation in turtles after 3 h anoxia at room temperature, suggesting that turtle hearts most likely do not suffer oxidative injury after anoxia because their mitochondria produce no excess O2·- upon reoxygenation. Instead, our data support the conclusion that both the low levels of succinate accumulation and the maintenance of ADP levels in the anoxic turtle heart are key factors in preventing the surge of O2·- production upon reoxygenation.

Population structure and dynamics of the Mediterranean Pond Turtle Mauremys leprosa (Schweigger, 1812) in contrasted polluted aquatic environments

Pollution contributes to the degraded state of continental aquatic ecosystems and biodiversity. Some species appear to be tolerant to aquatic pollution, yet little is known about the effects of such pollution on population structure and dynamics. Here, we investigated how wastewater treatment plant (WWTP) effluents of the Cabestany City, in southern France, contribute to the pollution levels of the Fosseille River, and we tested how they could affect population structure and medium-term dynamics of the native freshwater turtle, the Mediterranean Pond Turtle Mauremys leprosa (Schweigger, 1812). Amongst the 68 pesticides surveyed from water samples collected along the river in 2018 and 2021, a total of 16 pesticides were detected, among which eight were found in the upstream section of the river, 15 in the river section located downstream of the WWTP, and 14 in the outfall of the WWTP, exhibiting the contribution of effluents to the river pollution. From 2013 to 2018 and in 2021, capture-mark-recapture protocols were carried out on the freshwater turtle population living in the river. Using robust design and multi-state models, we showed a stable population throughout the study period, with high year-dependent seniority, and a bidirectional transition occurring primarily from the upstream to the downstream river sections of the WWTP. The freshwater turtle population consisted mostly of adults, with a male biased sex ratio detected downstream of the WWTP neither related to sex-dependent survival, recruitment, nor transition, suggesting a male bias in the hatchlings or primary sex ratio. Also, the largest immatures and females were captured downstream of the WWTP, with females having the highest body condition, whereas no such differences were observed in males. This study highlights that population functioning of M. leprosa is driven primarily by effluents induced resources, at least over the medium-term.

Correction to “Amazonian run‐of‐river dam reservoir impacts underestimated: Evidence from a before–after control–impact study of freshwater turtle nesting areas”

Correction to “Amazonian run‐of‐river dam reservoir impacts underestimated: Evidence from a before–after control–impact study of freshwater turtle nesting areas”

Factors Affecting Nest Site Selection by Freshwater Turtles: A Systematic Review

Nest site selection is an important behavior, particularly in species that lack parental care, as nest microclimate can greatly impact embryos’ survival and offspring phenotype. Understanding which factors influence oviposition decisions is critical to identifying priority areas for conservation. This systematic review aimed to synthesize the factors that affect nest site selection by freshwater turtles. The search was conducted in the Web of Science database. In total, 35 publications met the eligibility criteria. The first study on the topic was published more than three decades ago, but only within the last ten years have studies started to be published annually. More than half of the studies were conducted in the United States and the most studied species was Chrysemys picta. Environmental factors, mainly vegetation characteristics, but also soil properties and beach morphology, are the most studied. Anthropogenic factors have been increasingly studied, especially residential areas and agricultural fields. Some studies suggest that human-altered habitats may act as ecological traps, emphasizing the need for further research on this topic. More studies are also needed on the influence of predation risk, co-species cues, female size, and offspring phenotype on nest site selection by freshwater turtles. We highlight that understanding the factors affecting nest site selection is important for identifying the habitat needs of nesting females, predicting possible ecological implications of nest site choice, assessing the adaptive potential of species to environmental change, and determining the vulnerability of populations to different threats.

Epistylis spp. Infestation in Two Species of Mud Turtles (Kinosternon spp.) in the American Southwest.

The protistan genus Epistylis contains freshwater colonial species that attach to aquatic organisms in an epibiotic or parasitic relationship. They are known to attach to the epidermis and shells of aquatic turtles, but have not been reported to cause heavy infestations or morbidity in turtles. We documented heavy infestations of Epistylis spp. in several populations of Sonoran mud turtles (Kinosternon sonoriense) inhabiting livestock ponds in Arizona, USA, and rough-footed mud turtles (Kinosternon hirtipes) from livestock ponds in Texas, USA, over the course of several years. Severe Epistylis spp. infestations on mud turtles appeared to alter diving and swimming behavior when compared to uninfested conspecifics. Infestations were cleared in captivity using tap water or a 10% salt solution, and the turtles had no permanent damage to their shell or epidermis upon clearing. While several of the mud turtles we observed had poor body condition, it is possible that the severe infestations we observed were caused by a comorbidity associated with a pathogen, parasite, or poor habitat quality that made the turtles more susceptible to the Epistylis spp. infestation. Further research on causes for these severe infestations are warranted because they contribute to changes in behavior of the heavily infested turtles and may contribute to morbidity in Kinosternon spp. when mud turtles inhabit extremely warm, shallow, eutrophic aquatic habitats, such as livestock ponds.

Monitoring the Diversity of Amphibian and Reptiles In the Upstream part of Code River Using e-DNA Method

Research on the diversity of amphibians and reptiles on the upstream part of Code River had been done in 2012 and 2017. Result on two previous results were found anurans, snakes and lizards but we did not find any freshwater turtles. Method used on the 2012 and 2017 research was conventional using Visual Encounter Survey (VES). Conventional methods such as VES have limitations, which was the inability to detect difficult-to-find animals such as freshwater turtles. Therefore, a new approach was taken to monitor the diversity of amphibians and reptiles especially to detect freshwater turtles in the Code River, namely the environmental DNA (eDNA) method. The purpose of this research were to monitor the diversity of amphibians and reptiles, and to reveals eDNA sampling efficiency compared to VES. An e-DNA metabarcoding process is conducted with universal CO1 primer on the water sample taken from upstream part of Code River. The results obtained were compared to the data from conventional studies held in 2012 and 2017. The results in 2021 found 12 species of amphibians but all of these species did not naturally distribute in Yogyakarta and even in Indonesia. Furthermore, 5 species of snakes were found, with only 1 species of snake naturally occur in Yogyakarta. Subsequently, we found 6 species of lizards whose natural distribution does not exist in Yogyakarta and even in Indonesia. Finally, we obtained 1 species of tortoise whose natural distribution does not exist in Yogyakarta and even in Indonesia. By far, in Indonesia the identification of amphibian and reptile species in rivers using the e-DNA method has shown less accurate results. The inaccuracy may be due to the lack of specificity of the sequence targets and primers for monitoring reptiles and amphibians in rivers. The target sequences used in this study did not have significant differences between species in reptiles and amphibians, so that the herpetofauna that had been recorded in the Code River were not identified using the e-DNA method. Based on this research, conventional sampling is recommended for monitoring herpetofauna in river areas.
 Keywords: Monitoring, Amphibians; Reptiles; Code River, e-DNA

Using a handheld metal detector to detect ingested hooks and other metallic objects in freshwater turtles

AbstractTurtles can be unintentionally hooked during recreational and commercial fishing operations. While hook ingestion is not always fatal, ingested hooks can harm or kill turtles by damaging soft tissues or affecting digestion. Detecting ingested hooks and other metallic debris in the field is a challenge. As such, we tested the efficacy of a handheld metal detector in detecting ingested fish hooks and incidental metallic debris in freshwater turtles in Georgia, USA. We captured 426 individual freshwater turtles representing 4 species and radiographed 106 yellow‐bellied sliders (Trachemys scripta scripta). Of 37 turtles that tested positive with a handheld metal detector, radiographs revealed 17 (46%) had ingested at least one hook, 15 (40%) had ingested an unidentifiable metal object or objects, and 5 (14%) showed no clear signs of hooks or other metallic objects. All 69 turtles that tested negative in the field and were radiographed showed no signs of metal ingestion. Accordingly, our proportion of false positives was 14% (5 of 37), false negatives (metal not detected in field but on follow‐up radiograph) were 0% (0 of 69), and our overall accuracy at detecting ingested metal with a handheld metal detector was 95% (101 of 106 radiographed turtles). Thus, handheld metal detectors may be a useful tool for detecting ingested hooks and other metallic objects in freshwater turtles.

Freshwater turtle admissions to a wildlife hospital in South-East Queensland, Australia over an eleven-year period, 2010-2021.

Freshwater turtles in South-East Queensland face a multitude of anthropogenic threats that threaten their survival. Research exploring the morbidity and mortality of animals presented to wildlife hospitals has been used globally to assess the health of species populations, investigate anthropogenic interference and provide valuable information to veterinary professionals about ailments common to a particular species. Medical records of 1739 chelonian patients admitted to Currumbin Wildlife Hospital, Currumbin, Queensland, Australia between March 2010 and March 2021 were analysed to obtain data on species, diagnoses, outcome and temporal trends. Six species of freshwater turtles were observed, with the Brisbane River turtle (Emydura macquarii signata) being the most common. While there was no significant trend in the number of cases over the study period, there was a decline in the number of Saw-shell turtles (Myuchelys latisternum) admitted each year. Admissions peaked in autumn and summer, likely coinciding with nesting and hatchling emergence. Trauma was the most common diagnosis, accounting for 83% of cases, and saw a decreasing incidence during the study period. In contrast, there was an increasing number of turtles presenting with disease within the same period. Overall, 67.4% of turtles were able to be released after a period of treatment, while 32.6% were euthanised or died due to their condition. Turtles presenting for trauma had the most favourable prognosis, and disease held the poorest prognosis. These results confirmed that there are significant anthropogenic threats to freshwater turtle populations in South-East Queensland.

Seasonal, environmental and anthropogenic influences on nocturnal basking in turtles and crocodiles from North‐Eastern Australia

AbstractMany ectotherms bask in the sun as a behavioural mechanism to increase body temperature and facilitate metabolism, digestion or gamete production, among other functions. Such behaviours are common during the day, but some nocturnal species are also known to thermoregulate at night, in the absence of solar radiation, through shifts in body posture or microhabitat selection. Additionally, recent work has documented nocturnal basking in freshwater turtles in tropical Australia, though the purpose of the behaviour remains unknown. Here, we have built upon that work to test: 1. seasonal differences, 2. the influence of environmental factors and 3. the influence of anthropogenic development (e.g. river‐front houses) on nocturnal basking behaviour. We visually surveyed transects repeatedly at night on the Ross River, Townsville, QLD, Australia from March to November 2020 and documented nocturnal basking in both freshwater turtles (Emydura macquarii krefftii) and freshwater crocodiles (Crocodylus johnstoni). For both taxa, we found significantly more nocturnal basking activity during the hotter months. Likewise, water surface temperature significantly influenced nocturnal basking in both taxa, especially when water temperatures were both high and warmer than air temperatures. We propose that nocturnal basking provides a mechanism for thermoregulatory cooling when water temperatures are high (e.g. 30°C) and above‐preferred temperatures. After accounting for availability in basking habitat, both turtles and crocodiles basked more frequently on the undeveloped side of the river, suggesting avoidance of human activity or disturbance. This study is the first to document nocturnal basking activity temporally throughout the year as well as the first to identify the influences of environmental factors. Nocturnal thermoregulation has been documented in many reptiles, however, thermoregulatory cooling in tropical systems is less well‐known.

Genetic Relationship Between Founders of a Threatened Freshwater Turtle in a Mexican Wildlife Management Unit. A Conservation Strategy

Management Units for Wildlife Conservation (UMAs according to its Spanish acronym), are used for the ex-situ reproduction of freshwater turtles. These areas, often administered by local communities, are dedicated to conservation and sustainable management. The critically endangered freshwater turtle Dermatemys mawii has been successfully reproduced in several UMAs; however, no genetic management plan has been developed to maintain offspring genetic variability. Therefore, this study aims to determine the kinship relationship and homozygosity through the loci index of founder individuals in three UMAs devoted to the reproduction of D. mawii for the establishment of breeding groups. We collected skin samples of D. mawii in 2017 from 117 founder individuals from three UMAs located in the state of Tabasco, southeast Mexico. Ten specific D. mawii microsatellite markers were used for genotyping the founder individuals. We estimated the pedigree relationship between founders and proposed the formation of three breeding groups to optimize the use of related and non-related individuals to meet UMA-specific objectives and evaluated the genetic diversity retention of the breeding groups. The breeding groups were integrated as follows: 1) conservation breeding group consisting of 16 unrelated females and 7 unrelated males that presented a lower level of homozygosity (< 0.4); 2) research breeding group consisting of 45 females and 16 males that were unrelated or presented a half-sibling relationship and with a medium level of homozygosity (<0.6); and 3) a sustainable breeding group comprising 29 females and 4 males that were not necessarily unrelated and with a high level of homozygosity (> 0.6). Genetic diversity retention (Ho, He) was highest for the conservation breeder group and research breeder group. UMAs can create 3 breeding groups with different objectives: 1) species conservation, 2) research, and 3) sustainable use of species. All breeding groups can retain genetic diversity. Our proposal can enrich conservation actions and sustainable use for D. mawii at both national and international levels, specifically within the Mesoamerican corridor.

A quantum leap in the evolution of platyhelminths: Host-switching from turtles to hippopotamuses illustrated from a phylogenetic meta-analysis of polystomes (Monogenea, Polystomatidae)

While monogenean worms are mainly parasites of the gills and skin of fish, and to a lesser extent parasites of the oral cavity, urinary bladder, and/or conjunctival sacs of amphibians and freshwater turtles, Oculotrema hippopotamiStunkard, 1924 is the single monogenean polystome reported from a mammal, the common hippopotamus (Hippopotamus amphibius Linnaeus). Several hypotheses have been suggested in the last decade to explain the origin of this enigmatic parasite which infects the conjunctival sacs of H. amphibius. Based on a molecular phylogeny inferred from nuclear (28S and 18S) and mitochondrial (12S and COI) sequences of O. hippopotami and chelonian polystomes, we found a sister group relationship between O. hippopotami and Apaloneotrema moleri (Du Preez & Morrison, 2012). This result suggests lateral parasite transfer between freshwater turtles and hippopotamuses, thus likely reflecting one of the most exceptional known examples of host-switching in the course of vertebrate evolution. It also demonstrates that the proximity in the ecological habitat of parasites within host species is an important feature for their speciation and diversification. Because A. moleri and its host, the Florida softshell turtle (Apalone ferox (Schneider)), are restricted to the USA, we suggest that an ancestral stock of parasites may have been isolated on primitive African trionychids after they diverged from their American relatives, and then switched to hippopotamuses or anthracotheres in Africa.