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Ecotoxicology (London, England) May 2021Worldwide petroleum exploration and transportation continue to impact the health of the marine environment through both catastrophic and chronic spillage. Of the... (Review)
Review
Worldwide petroleum exploration and transportation continue to impact the health of the marine environment through both catastrophic and chronic spillage. Of the impacted fauna, marine reptiles are often overlooked. While marine reptiles are sensitive to xenobiotics, there is a paucity of petroleum toxicity data for these specialized fauna in peer reviewed literature. Here we review the known impacts of petroleum spillage to marine reptiles, specifically to marine turtles and iguanas with an emphasis on physiology and fitness related toxicological effects. Secondly, we recommend standardized toxicity testing on surrogate species to elucidate the mechanisms by which petroleum related mortalities occur in the field following catastrophic spillage and to better link physiological and fitness related endpoints. Finally, we propose that marine reptiles could serve as sentinel species for marine ecosystem monitoring in the case of petroleum spillage. Comprehensive petroleum toxicity data on marine reptiles is needed in order to serve as a foundation for future research with newer, unconventional crude oils of unknown toxicity such as diluted bitumen.
Topics: Animals; Ecosystem; Petroleum; Petroleum Pollution; Reptiles; Toxicity Tests
PubMed: 33725237
DOI: 10.1007/s10646-021-02359-9 -
Sexual Development : Genetics,... 2023Reptiles and amphibians provide untapped potential for discovering how a diversity of genetic pathways and environmental conditions are incorporated into developmental... (Review)
Review
BACKGROUND
Reptiles and amphibians provide untapped potential for discovering how a diversity of genetic pathways and environmental conditions are incorporated into developmental processes that can lead to similar functional outcomes. These groups display a multitude of reproductive strategies, and whereas many attributes are conserved within groups and even across vertebrates, several aspects of sexual development show considerable variation.
SUMMARY
In this review, we focus our attention on the development of the reptilian and amphibian ovary. First, we review and describe the events leading to ovarian development, including sex determination and ovarian maturation, through a comparative lens. We then describe how these events are influenced by environmental factors, focusing on temperature and exposure to anthropogenic chemicals. Lastly, we identify critical knowledge gaps and future research directions that will be crucial to moving forward in our understanding of ovarian development and the influences of the environment in reptiles and amphibians.
KEY MESSAGES
Reptiles and amphibians provide excellent models for understanding the diversity of sex determination strategies and reproductive development. However, a greater understanding of the basic biology of these systems is necessary for deciphering the adaptive and potentially disruptive implications of embryo-by-environment interactions in a rapidly changing world.
Topics: Animals; Female; Reptiles; Amphibians; Sex Differentiation; Ovary; Temperature; Sex Determination Processes
PubMed: 36380624
DOI: 10.1159/000526009 -
PeerJ 2022Declines of large-bodied herbivorous reptiles are well documented, but the consequences for ecosystem function are not. Understanding how large-bodied herbivorous...
BACKGROUND
Declines of large-bodied herbivorous reptiles are well documented, but the consequences for ecosystem function are not. Understanding how large-bodied herbivorous reptiles engineer ecosystems is relevant given the current interest in restoration of tropical islands where extinction rates are disproportionately high and reptiles are prominent as herbivores.
METHODS
In this study, we measured the ecosystem-level outcomes of long-term quasi-experiment represented by two adjacent islands within the Galapagos Archipelago, one with and the other without Galapagos land iguanas (), large-bodied herbivores known to feed on many plant species. We characterized plant communities on each island by developing high-resolution (<1 cm) aerial imagery and delineating extent of plant associations and counting individual plants on each.
RESULTS
In the presence of iguanas there was dramatically less woody plant cover, more area with seasonal grasses, and many fewer cacti. Cacti had a more clumped distribution where iguanas were absent than where iguanas were present.
DISCUSSION
This study provided strong evidence that Galapagos land iguanas can substantially engineer the structure of terrestrial plant communities; therefore, restoration of large-bodied reptilian herbivores, such as land iguanas and giant tortoises, should be regarded as an important component of overall ecosystem restoration, especially for tropical islands from which they have been extirpated.
Topics: Animals; Iguanas; Ecosystem; Lizards; Plants; Turtles
PubMed: 35116195
DOI: 10.7717/peerj.12711 -
Comparative Biochemistry and... Sep 2022Obesity is common in captive reptiles, and reptiles are increasingly popular as companion animals and in physiological research. Obesity may present a challenge during...
Obesity is common in captive reptiles, and reptiles are increasingly popular as companion animals and in physiological research. Obesity may present a challenge during surgical procedures using inhalation anaesthesia, as the long induction time due to the low reptilian metabolism may increase anaesthetic accumulation in the adipose tissues. This study investigated the impact of obesity on induction and recovery times from inhaled anaesthesia. The temporal change in the partial pressure of isoflurane in different tissues was predicted using a multi-compartment model. Furthermore, as right-to-left shunting can delay anaesthetic uptake and washout, we included an assessment of the combination of cardiac shunting and obesity. The model predictions indicate a clear increase in time to reach 90% equilibration of administered anaesthetic in the brain (T) of obese non-shunting (lean 47 min, obese >100 min) and shunting (lean 81 min, obese >100 min) reptiles. The combination of obesity and shunting doubled the time to acquisition of mean anaesthetic concentration (a measure used to plan anaesthesia) from 8 min to 19 min. Adipose blood flow highly affected whether the body type had an impact on induction time, with low adipose blood flow abolishing the effect of body type. As T was never reached within 100 min with both the obese reptiles, it was not possible to conclude on the effect of obesity on recovery times within this study. Care should therefore be taken when anaesthetising obese reptiles for surgical purposes, to ensure adequate anaesthetic depth is attained, and recovery monitored closely.
Topics: Anesthesia, Inhalation; Anesthetics; Animals; Isoflurane; Obesity; Reptiles
PubMed: 35659976
DOI: 10.1016/j.cbpa.2022.111255 -
Trends in Parasitology Aug 2020Reptiles are reservoirs of a wide range of pathogens, including many protozoa, helminths, pentastomids, and arthropod parasitic species, some of which may be of public... (Review)
Review
Reptiles are reservoirs of a wide range of pathogens, including many protozoa, helminths, pentastomids, and arthropod parasitic species, some of which may be of public health concern. In this review we discuss the zoonotic risks associated with human-reptile interactions. Increased urbanization and introduction of exotic species of reptile may act as drivers for the transmission of zoonotic parasites through the environment. In addition, being a part of human diet, reptiles can be a source of life-threatening parasitoses, such as pentastomiasis or sparganosis. Finally, reptiles kept as pets may represent a risk to owners given the possibility of parasites transmitted by direct contact or fecal contamination. Awareness of reptile-borne zoonotic parasitoses is important to advocate control, prevention, and surveillance of these neglected diseases.
Topics: Animals; Food Parasitology; Humans; Parasites; Parasitic Diseases; Pets; Reptiles; Zoonoses
PubMed: 32448703
DOI: 10.1016/j.pt.2020.04.014 -
ELife Nov 2022A predominantly fish-eating diet was envisioned for the sail-backed theropod dinosaur when its elongate jaws with subconical teeth were unearthed a century ago in...
A predominantly fish-eating diet was envisioned for the sail-backed theropod dinosaur when its elongate jaws with subconical teeth were unearthed a century ago in Egypt. Recent discovery of the high-spined tail of that skeleton, however, led to a bolder conjecture that was the first fully aquatic dinosaur. The 'aquatic hypothesis' posits that was a slow quadruped on land but a capable pursuit predator in coastal waters, powered by an expanded tail. We test these functional claims with skeletal and flesh models of . We assembled a CT-based skeletal reconstruction based on the fossils, to which we added internal air and muscle to create a posable flesh model. That model shows that on land was bipedal and in deep water was an unstable, slow-surface swimmer (<1 m/s) too buoyant to dive. Living reptiles with similar spine-supported sails over trunk and tail are used for display rather than aquatic propulsion, and nearly all extant secondary swimmers have reduced limbs and fleshy tail flukes. New fossils also show that ranged far inland. Two stages are clarified in the evolution of , which is best understood as a semiaquatic bipedal ambush piscivore that frequented the margins of coastal and inland waterways.
Topics: Animals; Dinosaurs; Fossils; Skeleton; Muscles; Spine
PubMed: 36448670
DOI: 10.7554/eLife.80092 -
PLoS Neglected Tropical Diseases Jul 2023The world-famous markets of Marrakech, also known in Arabic as souks, harbor a vast diversity of reptiles that are sold for medicinal/magic/pet purposes or used for...
The world-famous markets of Marrakech, also known in Arabic as souks, harbor a vast diversity of reptiles that are sold for medicinal/magic/pet purposes or used for snake charming. This unique epidemiological context has never been studied considering the interactions of humans, reptiles, and zoonotic pathogens. Thus, the aim of this study was to identify the parasites and pathogens present in blood and feces associated with handled reptiles in the markets of Marrakech to assess the risk of zoonotic transmission within the reptile-human interface. Privately owned reptiles (n = 118), coming from vendors or snake charmers, were examined and blood and feces sampled. DNA was extracted and molecular screening (cPCR, nPCR, qPCR, dqPCR) was performed aiming to identify potentially zoonotic pathogens (i.e., Anaplasma/Ehrlichia spp., Rickettsia spp., Borrelia burgdorferi sensu lato, Coxiella burnetii, Babesia/Theileria spp., Cryptosporidium spp., Giardia spp., Leishmania spp., Cestoda). Overall, 28.9% (34/118) of reptiles were positive for at least one pathogen. In blood, Anaplasma spp. were detected in four snakes, with two Montpellier snakes positive for Anaplasma phagocytophilum, while Rickettsia spp. were detected in one Mediterranean chameleon and four puff adders. Leishmania tarentolae was molecularly detected in a Mediterranean chameleon and a Montpellier snake. In feces, the cox1 gene generated a myriad of sequences for nematodes, cestodes, fungi and bacteria. Importantly, Proteus vulgaris was identified from a Mediterranean chameleon. Cryptosporidium spp. nPCR yielded a positive sample (i.e., Cryptosporidium sp. apodemus genotype I) from a Moroccan worm lizard, as well as for bacteria such as Pseudomonas aeruginosa in an Egyptian cobra, and Morganella morganii from a puff adder. Results from this study demonstrated the risk of zoonotic transmission of microorganisms and parasites present in blood and feces from reptiles that are brought to the souks in Marrakech, Morocco, to be sold for medicinal purposes or used for snake charming, being in direct and straight contact with humans.
Topics: Animals; Humans; Cryptosporidiosis; Morocco; Cryptosporidium; Rickettsia; Parasites; Anaplasma; Snakes; Reptiles
PubMed: 37467211
DOI: 10.1371/journal.pntd.0011431 -
Developmental Dynamics : An Official... Sep 2021Amniote tails display a wide variety of features for adaptation to diverse environments. Each feature originates from its own distinct developmental processes, and these...
Amniote tails display a wide variety of features for adaptation to diverse environments. Each feature originates from its own distinct developmental processes, and these processes in turn attest to an organism's evolutionary history. In this perspective, we discuss the ontogeny of tails from embryonic to adult stages, amniote tail regeneration, the mechanisms underlying tail length and neural systems, and the benefits of studying tails across vertebrates, in mammals, birds, and non-avian reptiles.
Topics: Animals; Biological Evolution; Birds; Mammals; Reptiles; Vertebrates
PubMed: 33548113
DOI: 10.1002/dvdy.311 -
Ecology Letters Nov 2021The Tree of Life will be irrevocably reshaped as anthropogenic extinctions continue to unfold. Theory suggests that lineage evolutionary dynamics, such as age since...
The Tree of Life will be irrevocably reshaped as anthropogenic extinctions continue to unfold. Theory suggests that lineage evolutionary dynamics, such as age since origination, historical extinction filters and speciation rates, have influenced ancient extinction patterns - but whether these factors also contribute to modern extinction risk is largely unknown. We examine evolutionary legacies in contemporary extinction risk for over 4000 genera, representing ~30,000 species, from the major tetrapod groups: amphibians, birds, turtles and crocodiles, squamate reptiles and mammals. We find consistent support for the hypothesis that extinction risk is elevated in lineages with higher recent speciation rates. We subsequently test, and find modest support for, a primary mechanism driving this pattern: that rapidly diversifying clades predominantly comprise range-restricted, and extinction-prone, species. These evolutionary patterns in current imperilment may have important consequences for how we manage the erosion of biological diversity across the Tree of Life.
Topics: Amphibians; Animals; Biodiversity; Biological Evolution; Extinction, Biological; Genetic Speciation; Phylogeny; Reptiles
PubMed: 34510687
DOI: 10.1111/ele.13868 -
Proceedings. Biological Sciences Dec 2022Female genitalia are conspicuously overlooked in comparison to their male counterparts, limiting our understanding of sexual reproduction across vertebrate lineages....
Female genitalia are conspicuously overlooked in comparison to their male counterparts, limiting our understanding of sexual reproduction across vertebrate lineages. This study is the first complete description of the clitoris (hemiclitores) in female snakes. We describe morphological variation in size and shape ( = 9 species, 4 families) that is potentially comparable to the male intromittent organs in squamate reptiles (hemipenes). Dissection, diffusible iodine contrast-enhanced micro-CT and histology revealed that, unlike lizard hemiclitores, the snake hemiclitores are non-eversible structures. The two individual hemiclitores are separated medially by connective tissue, forming a triangular structure that extends posteriorly. Histology of the hemiclitores in Australian death adders () showed erectile tissue and strands/bundles of nerves, but no spines (as is found in male hemipenes). These histological features suggest the snake hemiclitores have functional significance in mating and definitively show that the hemiclitores are not underdeveloped hemipenes or scent glands, which have been erroneously indicated in other studies. Our discovery supports that hemiclitores have been retained across squamates and provides preliminary evidence of differences in this structure among snake species, which can be used to further understand systematics, reproductive evolution and ecology across squamate reptiles.
Topics: Humans; Animals; Male; Female; Biological Evolution; Australia; Snakes; Lizards; Genitalia, Male; Phylogeny
PubMed: 36515117
DOI: 10.1098/rspb.2022.1702