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light and scanning electron microscopic studies on the esophageal spines in the pacific ridley turtle, lepidochelys olivacea.the peculairly specialized esophagus of the pacific ridley turtle, lepidochelys olivacea, was described by light and scanning electron microscopic studies. the esophagus is lined by a stratified squamous epithelium with remarkable keratinization, and its major part forms a number of large spines which have been called "pharyngeal teeth." the epithelium consists of three strate: stratum germinativum, stratum spinosum and stratum corneum. the surface of the spine is covered by a scaly keratin of p ...19761275657
increased levels of arginine vasotocin and neurophysin during nesting in sea turtles.arginine vasotocin (avt) and neurophysin (np) levels were measured by radioimmunoassay in two species of sea turtle, the olive ridley, lepidochelys olivacea, and the loggerhead, caretta caretta, during the brief period of nesting and oviposition. in both species, avt was low in animals which were not reproductively active. avt was also low at the time animals emerged from the surf to nest, but increased significantly during oviposition and then declined as the animals returned to the water. np i ...19892707582
changes in lh and progesterone associated with the nesting cycle and ovulation in the olive ridley sea turtle, lepidochelys olivacea. 19826754526
monoclonal antibodies for the measurement of class-specific antibody responses in the green turtle, chelonia mydas.monoclonal antibodies (mabs) were developed against the known immunoglobulin classes of the green turtle, chelonia mydas. plasma protein fractions enriched for 5.7s igy, 7s igy, and igm turtle immunoglobulins were used to immunize balb/c mice for hybridoma production and for hybridoma screening. fifteen hybridomas produced mabs with specificity for turtle immunoglobulins and for affinity purified dinitrophenol (dnp) specific turtle antibodies. three mabs specific for either turtle 5.7s igy heavy ...19957502491
a molecular phylogeny for marine turtles: trait mapping, rate assessment, and conservation relevance.nucleotide sequences from the cytochrome b gene of mitochondrial dna were employed to resolve phylogenetic controversies and to assess molecular evolutionary rates in marine turtles (chelonioidea). findings of special relevance to conservation biology include discovery of a distant relationship between natator and other cheloniid species, the paraphyly of chelonia mydas with respect to chelonia agassizi, and genetic distinctiveness of lepidochelys kempi from lepidochelys olivacea. a longstanding ...19938516304
histological and ultrastructural study of the lingual epithelium of the juvenile pacific ridley turtle, lepidochelys olivacea (chelonia, cheloniidae).histological and ultrastructural studies ot the dorsal lingual epithelium of the juvenile pacific ridley turtle, lepidochelys olivacea, were performed by light and electron microscopy, and the results were compared to those of freshwater turtles in order to clarify the relationship between the histological and cellular differences of the lingual epithelium and the habitat of the turtles. the tongue of the juvenile pacific ridley turtle is triangular with a round apex when viewed from above, but ...19968712372
vibrio mimicus diarrhea following ingestion of raw turtle eggs.clinical and epidemiological characteristics of diarrhea associated with vibrio mimicus were identified in 33 hospitalized patients referred to the costa rican national diagnostic laboratory network between 1991 and 1994. the relevant symptoms presented by patients included abundant watery diarrhea, vomiting, and severe dehydration that required intravenous dhaka solution in 83% of patients but not fever. seroconversion against v. mimicus was demonstrated in four patients, from whom acute- and c ...19968919774
ultrastructure and characteristics of eggshells of the olive ridley turtle (lepidochelys olivacea) from gahirmatha, india.the structure of a chelonian eggshell is of prime importance for the developing embryo. it acts as a protective covering as well as mediator in the exchange of heat and water. the fresh eggshell of the olive ridley (lepidochelys olivacea) turtle displays a variety of structural forms in their aragonite framework. its netted substrate, loose texture and poorly organised crystallites favour the easy exchange of air and water during its development. the shell consists mostly of calcium in carbonate ...19969078397
correlation among thermosensitive period, estradiol response, and gonad differentiation in the sea turtle lepidochelys olivacea.reptile embryos with temperature sex determination have a thermosensitive period (tsp). the finding that exogenous estradiol (e2) overcomes the effect of male-promoting temperature led to the idea that temperature may regulate estrogen concentration in the gonad during tsp. since interspecific variations in tsp and in the effect of exogenous e2 exist, we undertook a study in the olive ridley lepidochelys olivacea. four parameters were correlated: the tsp (time dimension), the thermosensitive sta ...19979268618
response of diencephalon but not the gonad to female-promoting temperature with elevated estradiol levels in the sea turtle lepidochelys olivacea.although temperature sex determination is well known in several reptile species, the physiological mechanism underlying this process remains to be elucidated. in the current work, we analyzed the levels of testosterone (t) and estradiol (e2) in the gonads; two brain regions--telencephalon (te) and diencephalon/mesencephalon (di)--and the serum of developing embryos of the olive ridley lepidochelys olivacea incubated at male- or female-promoting temperatures. conversion of pregnenolone (p5) to t ...19989493349
sources of vibrio mimicus contamination of turtle eggs.vibrio mimicus contamination of sand increased significantly during the arrival of the olive ridley sea turtles (lepidochelys olivacea) at ostional anidation beach, costa rica. statistical analysis supports that eggs are contaminated with v. mimicus by contact with the sand nest. v. mimicus was isolated from eggs of all nests tested, and ctxa+ strains were found in 31% of the nests, all of which were near the estuary.19999872804
calcium metabolism in olive ridley turtle eggs during embryonic development.analyses of calcium, magnesium, sulphur, potassium and phosphorus content of the eggshell, yolk-albumen and embryos of olive ridley turtle, lepidochelys olivacea, have been carried out at various stages of embryonic development. calcium is the major inorganic constituent in the egg (shell and yolk-albumen) and embryos. other elements are present either in trace or in minute trace amounts. the egg contents (yolk and albumen) provide only 40% of the embryonic calcium requirement of the hatchling. ...19989883572
acetylcholinesterase-positive innervation is present at undifferentiated stages of the sea turtle lepidochelis olivacea embryo gonads: implications for temperature-dependent sex determination.in embryos of different reptile species, incubation temperature triggers a cascade of endocrine events that lead to gonad sex differentiation. the cellular and molecular mechanisms by which temperature sets in motion this process are still controversial. here, we begin evaluating the possible participation of the nervous system in temperature-dependent sex determination by showing the existence and origin of acetylcholinesterase (ache)-positive nerve fibers in undifferentiated gonads of the lepi ...199910397397
basal and stress-induced corticosterone levels in olive ridley sea turtles (lepidochelys olivacea) in relation to their mass nesting behavior.adrenocortical responsiveness to turning stress was examined in wild, reproductively-active olive ridley sea turtles (lepidochelys olivacea) in relation to their mass nesting (arribada) behavior. we hypothesized that the high sensitivity threshold (hst) observed in ovipositing sea turtles is associated with a diminished sensitivity of the hypothalamo-pituitary-adrenal (hpa) axis to stressful stimuli in arribada females. we tested this hypothesis by determining whether arribada females exhibited ...199910531552
differential expression of sox9 in gonads of the sea turtle lepidochelys olivacea at male- or female-promoting temperatures.in mouse and chick embryos, the sox9 gene is down-regulated in genetic females whereas in genetic males it remains in the sertoli cells. we studied the distribution of sox9 protein in developing genital ridges of embryos of the sea turtle lepidochelys olivacea incubated at male- or female-promoting temperatures, using the antibody for detection. at stages 22-24, cells in medullary cords show sox9 positive nuclei, while coelomic epithelial cells appear negative. at stage 25 however, most medullar ...199910531557
persistent infectivity of a disease-associated herpesvirus in green turtles after exposure to seawater.herpesviruses are associated with several diseases of marine turtles including lung-eye-trachea disease (letd) and gray patch disease (gpd) of green turtles (chelonia mydas) and fibropapillomatosis (fp) of green, loggerhead (caretta caretta), and olive ridley turtles (lepidochelys olivacea). the stability of chelonian herpesviruses in the marine environment, which may influence transmission, has not been previously studied. in these experiments, letd-associated herpesvirus (letv) was used as a m ...200011085447
temperature regulates sox9 expression in cultured gonads of lepidochelys olivacea, a species with temperature sex determination.although sex determination starts in the gonads, this may not be the case for species with temperature sex determination (tsd). since temperature affects the whole embryo, extragonadal thermosensitive cells may produce factors that induce gonadal sex determination as a secondary event. to establish if gonads of a species with tsd respond directly to temperature, pairs of gonads were cultured, one at female-promoting temperature (fpt) and the contralateral at male-promoting temperature (mpt). his ...200111150238
timing of sox9 downregulation and female sex determination in gonads of the sea turtle lepidochelys olivacea.the sry-related gene sox9 is involved in the differentiation of sertoli cells in male gonads of vertebrates with different kinds of sex determination. in the olive ridley lepidochelys olivacea, a species with temperature sex determination (tsd), the sox9 protein is expressed at stages 21-24 in medullary cells in gonads of embryos incubated at both male-(mpt) or female-promoting temperatures (fpt). however, at fpt the expression of sox9 protein decreases at stage 25 and disappears at stage 26, su ...200111555857
multiple paternity and female-biased mutation at a microsatellite locus in the olive ridley sea turtle (lepidochelys olivacea).multiple paternity in the olive ridley sea turtle (lepidochelys olivacea) population nesting in suriname was demonstrated using two microsatellite loci, viz., ei8 and cm84. the large number of offspring sampled per clutch (70 on average, ranging from 15 to 103) and the number of alleles found at the two loci (18 and eight alleles, respectively) enabled unambiguous assessment of the occurrence of multiple paternity. in two out of 10 clutches analysed, the offspring had been sired by at least two ...200212136412
expression profiles of dax1, dmrt1, and sox9 during temperature sex determination in gonads of the sea turtle lepidochelys olivacea.sex determination is controlled either by genetic or environmental factors. in mammals sry initiates determination but no homologue of this gene exists in non-mammalian species. other genes of the mammalian sex-determining pathway have been identified in gonads of different vertebrates. sox9, dax1, and dmrt1 are expressed at the onset of gonadal development in birds and reptiles. in the sea turtle lepidochelys olivacea, a species with temperature sex determination (tsd), sox9 is expressed in und ...200212409092
[identification of turtle shell, tortoise plastron and their counterfeit products].to identify the commercial chinese medicines turtle shell and tortoise plastron.200012512444
phylogeography of olive ridley turtles (lepidochelys olivacea) on the east coast of india: implications for conservation theory.orissa, on the east coast of india, is one of the three mass nesting sites in the world for olive ridley turtles (lepidochelys olivacea). this population is currently under threat as a result of fishery-related mortality; more than 100 000 olive ridleys have been counted dead in the last 10 years in orissa. in general, the globally distributed olive ridley turtle has received significantly less conservation attention than its congener, the kemp's ridley turtle (l. kempi), because the latter is r ...200415189212
plastic debris ingestion by sea turtle in paraíba, brazil.coastal gill net entanglement and debris intake are important threats to the survival of sea turtles. two sea turtles (lepidochelys olivacea and chelonia mydas) were found stranded along the coast of paraíba. after necropsy, plastic debris were found in the stomach. the debris is described. this is the first record of this sort of problem for the paraíba littoral.200415341830
genomic variation of the fibropapilloma-associated marine turtle herpesvirus across seven geographic areas and three host species.fibropapillomatosis (fp) of marine turtles is an emerging neoplastic disease associated with infection by a novel turtle herpesvirus, fibropapilloma-associated turtle herpesvirus (fpthv). this report presents 23 kb of the genome of an fpthv infecting a hawaiian green turtle (chelonia mydas). by sequence homology, the open reading frames in this contig correspond to herpes simplex virus genes ul23 through ul36. the order, orientation, and homology of these putative genes indicate that fpthv is a ...200515613340
the sea-finding behavior of hatchling olive ridley sea turtles, lepidochelys olivacea, at the beach of san miguel (costa rica).newly hatched olive ridley sea turtles (lepidochelys olivacea) were tested for their directional preferences in a sand-filled circular arena in total darkness. hatchlings that had crawled about 5 m on the beach, toward the sea preferred the southwesterly direction that would have brought them to the water line, whereas hatchlings that had been denied this experience headed eastward, a direction of unclear origin. these data suggest that a short crawl across the natural beach can set the directio ...200515834543
the panmixia paradigm of eastern pacific olive ridley turtles revised: consequences for their conservation and evolutionary biology.previous studies of the olive ridley lepidochelys olivacea population structure in the tropical eastern pacific have indicated the existence of a single panmictic population ranging from costa rica to mexico. this information has been used to design specific management measures to conserve primary nesting beaches in mexico. however, little is known about olive ridleys in the baja california peninsula, their northernmost reproductive limit, where recent observations have shown differences in nest ...200516156806
energetics during hatchling dispersal of the olive ridley turtle lepidochelys olivacea using doubly labeled water.studies of metabolism are central to the understanding of the ecology, behavior, and evolution of reptiles. this study focuses on one phase of the sea turtle life cycle, hatchling dispersal, and gives insight into energetic constraints that dispersal imposes on hatchlings. hatchling dispersal is an energetically expensive phase in the life cycle of the olive ridley turtle lepidochelys olivacea. field metabolic rates (fmrs), determined using the doubly labeled water (dlw) method, for l. olivacea ...201316555197
microsatellites provide insight into contrasting mating patterns in arribada vs. non-arribada olive ridley sea turtle rookeries.molecular studies of sea turtles have shown that the frequency of multiple paternity (mp) varies between species, and between rookeries of the same species. this study uses nuclear microsatellite markers to compare the incidence of mp in two neighbouring olive ridley rookeries on the pacific coast of costa rica, with contrasting nesting behaviours -- the 'arribada' population nesting at ostional and the solitary nesters of playa hermosa. using two highly polymorphic microsatellite markers, we te ...200616842427
heavy metals in the tissues of the sea turtle lepidochelys olivacea from a nesting site of the northwest coast of mexico. 200616977518
ontogeny of energetics in leatherback (dermochelys coriacea) and olive ridley (lepidochelys olivacea) sea turtle hatchlings.changes in activity related oxygen consumption were measured in leatherback and olive ridley sea turtle hatchlings over their first month after emergence from the nest. leatherbacks emerged with 75-90 kj of energy in the residual yolk for growth and activity whereas olive ridleys emerged with 45 kj. in leatherbacks (n=8), resting mass-specific oxygen consumption rates decreased by 53% over the first post-hatching month (0.34+0.03 ml o(2) h(-1) g(-1) to 0.16+0.01 ml o(2) h(-1) g(-1), respectively ...200717126576
respiration in neonate sea turtles.the pattern and control of respiration is virtually unknown in hatchling sea turtles. using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (dermochelys coriacea) and olive ridley (lepidochelys olivacea) turtle hatchlings for the first six days after pipping. in addition, we tested the hatchlings' response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. hatchling sea turtles generally showed resting ven ...200717258487
population genetics and phylogeography of sea turtles.the seven species of sea turtles occupy a diversity of niches, and have a history tracing back over 100 million years, yet all share basic life-history features, including exceptional navigation skills and periodic migrations from feeding to breeding habitats. here, we review the biogeographic, behavioural, and ecological factors that shape the distribution of genetic diversity in sea turtles. natal homing, wherein turtles return to their region of origin for mating and nesting, has been demonst ...200717944856
haematology and plasma chemistry of breeding olive ridley sea turtles (lepidochelys olivacea). 200718083982
[cloacal and nasal bacterial flora of lepidochelys olivacea (testudines: cheloniidae) from the north pacific coast of costa rica].cloacal and nasal bacterial flora of lepidochelys olivacea (testudines: cheloniidae) from the north pacific coast of costa rica. the aerobic cloacal and nasal bacterial flora of 45 apparently healthy female olive ridley sea turtles (lepidochelys olivacea) was studied at nancite nesting beach, in santa rosa national park (costa rican north pacific) during july and august 2002. bacterial samples were obtained by inserting sterile swabs directly into the cloaca and the nasal cavities of the turtles ...200618457173
density-dependent effects on hatching success of the olive ridley turtle, lepidochelys olivacea.historically, the olive ridley arribada at playa nancite, costa rica, was one of the largest olive ridley arribadas in the eastern pacific with 70,000 nesting females in a year. recently the nancite arribada drastically declined. we hypothesized that the population decline at playa nancite could have been due to low hatching success as a result of the high density of nests on the beach, such that recruitment to the population was insufficient to balance losses. to test this hypothesis, we examin ...200818481091
mexican turtle oils; lepidochelis olivacea esch. 194818900102
cloning and expression of the estrogen receptor-alpha (esr1) from the harderian gland of the sea turtle (lepidochelys olivacea).the effects of estradiol on the harderian gland (hg) are believed to be partially regulated by the transcriptional regulation of the estrogen-related genes via estrogen receptor (er). in reptiles, however, it has not been well established whether the hg contains or expresses steroid nuclear receptors. as a first step toward investigating the molecular mechanisms of estrogen signalling in the hg, we isolated the cdna for eralpha in the sea turtle lepidochelys olivacea. eralpha was cloned using rt ...200919272391
detection of polymorphisms of the mtdna control region of caretta caretta (testudines: cheloniidae) by pcr-sscp.marine turtles are increasingly being threatened worldwide by anthropogenic activities. better understanding of their life cycle, behavior and population structure is imperative for the design of adequate conservation strategies. the mtdna control region is a fast-evolving matrilineal marker that has been employed in the study of marine turtle populations. we developed and tested a simple molecular tracing system for caretta caretta mtdna haplotypes by polymerase chain reaction-single strand con ...200919283688
the characterization of cytosolic glutathione transferase from four species of sea turtles: loggerhead (caretta caretta), green (chelonia mydas), olive ridley (lepidochelys olivacea), and hawksbill (eretmochelys imbricata).glutathione s-transferases (gst) play a critical role in the detoxification of exogenous and endogenous electrophiles, as well as the products of oxidative stress. as compared to mammals, gst activity has not been extensively characterized in reptiles. throughout the globe, most sea turtle populations face the risk of extinction. of the natural and anthropogenic threats to sea turtles, the effects of environmental chemicals and related biochemical mechanisms, such as gst catalyzed detoxification ...200919460460
lead in blood and eggs of the sea turtle, lepidochelys olivacea, from the eastern pacific: concentration, isotopic composition and maternal transfer.concentrations of lead were assessed in the sea turtle, lepidochelys olivacea, from a nesting colony of the eastern pacific. twenty-five female turtles were sampled and a total of 250 eggs were collected during the "arribada" event of the 2005-2006 season. considering the nesting season, the maternal transfer of lead (pb) via egg-laying, in terms of metal burden in whole body, was 0.5%. pb concentrations (in dry weight) in blood (0.95+/-0.18microgg(-1)) and egg samples (yolk, 0.80+/-0.10microg g ...201019897213
balaenophilus manatorum (ortíz, lalana and torres, 1992) (copepoda: harpacticoida) from loggerhead sea turtles, caretta caretta, from japan and the western mediterranean: amended description and geographical comparison.the ectoparasitic harpacticoid copepod, balaenophilus manatorum (ortíz, lalana and torres, 1992) (syn. balaenophilus umigamecolus ogawa, matsuzaki and misaki, 1997), has been reported on 3 species of marine turtles from the pacific and the mediterranean and from the west indian manatee off cuba in the caribbean. the 3 available descriptions of this species were made using light microscopy. in this paper, we provide an amended description of b. manatorum using scanning electronic microscopy (sem) ...201019958046
trace metals (cd, cu, ni, and zn) in blood and eggs of the sea turtle lepidochelys olivacea from a nesting colony of oaxaca, mexico.trace metals (cd, cu, ni, and zn) concentrations were assessed in the sea turtle lepidochelys olivacea from a nesting colony of oaxaca, mexico. twenty-five female turtles were sampled, a total of 250 eggs were collected during the "arribada" event of the 2005-2006 season. zn concentrations were highest in the yolk [72.3 ± 10.9 μg/g dry weight (dw)] and blood (58.4 ± 4.7 μg/g dw), whereas ni concentrations were highest in the shell (48.5 ± 12.9 μg/g dw). the mean concentrations of cu, and cd in t ...201020396874
hox gene expression in the embryonic genital system of the sea turtle lepidochelys olivacea (eschscholt, 1829), a species with temperature-dependent sex determination.hox genes are conserved transcription factors which regulate embryonic morphogenesis and differentiation. for the first time, we examined the quantitative and spatial expression of two hox 5' genes, hoxd11 and hoxa13, in the developing genital system of the olive ridley lepidochelys olivacea, a species with temperature-dependent sex determination. quantitative and spatial expression patterns of both genes suggest a role in the female pathway rather than the male pathway. for instance, both genes ...201020601165
pathology and distribution of sea turtles landed as bycatch in the hawaii-based north pacific pelagic longline fishery.we examined the gross and microscopic pathology and distribution of sea turtles that were landed as bycatch from the hawaii, usa-based pelagic longline fishery and known to be forced submerged. olive ridley turtles (lepidochelys olivacea) composed the majority of animals examined, and hook-induced perforation of the esophagus was the most common gross lesion followed by perforation of oral structures (tongue, canthus) and of flippers. gross pathology in the lungs suggestive of drowning was seen ...201020688635
systemic mycosis caused by trichophyton spp. in an olive ridley sea turtle (lepidochelys olivacea): an immunohistochemical study.a sub-adult female olive ridley sea turtle (lepidochelys olivacea) was found floating off the coast of gran canaria, canary islands, spain. clinical and pathological findings: the turtle was lethargic and weak, and died one day after it was found. necropsy was performed and selected samples of lung and liver were routinely processed for histopathological and immunohistological studies. grossly, round, ulcerative lesions were observed on the rear flippers. the liver, spleen, coelomic wall, gastri ...201121409736
biotransformation of 2,2',5,5'-tetrachlorobiphenyl (pcb 52) and 3,3',4,4'-tetrachlorobiphenyl (pcb 77) by liver microsomes from four species of sea turtles.the rates of oxidative metabolism of two tetrachlorobiphenyl congeners were determined in hepatic microsomes from four species of sea turtles, green (chelonia mydas), olive ridley (lepidochelys olivacea), loggerhead (caretta caretta), and hawksbill (eretmochelys imbricata). hydroxylation of 3,3',4,4'-tetrachlorobiphenyl (pcb 77), an ortho-meta unsubstituted rodent cytochrome p450 (p450) 1a substrate pcb, was not observed in sea turtle microsomes. sea turtle microsomes hydroxylated 2,2',5,5'-tetr ...201121480586
mercury in blood and eggs of the sea turtle lepidochelys olivacea from a nesting colony in oaxaca, mexico.mercury concentrations were assessed in the sea turtle lepidochelys olivacea from a nesting colony of oaxaca, mexico; 25 female turtles were sampled, a total of 250 eggs were collected during the season 2005-2006. higher concentrations were found in yolk fraction, while in blood and albumen mean levels were below of 0.0010μg g(-1) dry wt. on the basis of one nesting season, the maternal transfer of hg via eggs-laying was estimated in 2.0±1.1%. according to international norms, the health of this ...201121529853
using satellite tracking to optimize protection of long-lived marine species: olive ridley sea turtle conservation in central africa.tractable conservation measures for long-lived species require the intersection between protection of biologically relevant life history stages and a socioeconomically feasible setting. to protect breeding adults, we require knowledge of animal movements, how movement relates to political boundaries, and our confidence in spatial analyses of movement. we used satellite tracking and a switching state-space model to determine the internesting movements of olive ridley sea turtles (lepidochelys oli ...201121589942
Reproductive synchrony in a recovering bottlenecked sea turtle population.1. The assessment of species extinction risk has been well established for some time now. Assessing the potential for recovery in endangered species is however much more challenging, because complementary approaches are required to detect reliable signals of positive trends. 2. This study combines genetics, demography and behavioural data at three different time-scales to assess historical and recent population changes and evidence of reproductive synchrony in a small population of olive ridley ...201122007680
formation of the genital ridges is preceded by a domain of ectopic sox9-expressing cells in lepidochelys olivacea.bipotential gonads represent the structural framework from which alternative molecular sex determination networks have evolved. maintenance of sox9 expression in sertoli cells is required for the structural and functional integrity of male gonads in mammals and probably in most amniote vertebrates. however, spatial and temporal patterns of sox9 expression have diversified along evolution. species with temperature sex determination are an interesting predictive model since one of two alternative ...201222008791
[Chemical composition of eggs of the Olive Ridley Lepidochelys olivacea (Testudines: Cheloniidae) and it's potential as a food source].The Olive Ridley is a worldwide distributed species with high nesting production per season, and in La Escobilla Oaxaca, México, there is a 70% of non-hatched eggs that are lost. In order to evaluate their potential use as a source for human and animal food products, their chemical composition was analyzed. Lyophilized egg samples from 25 turtles were obtained and were analyzed following the analytical methods for fatty acids, protein, fat, ash, moisture, amino acids, vitamins, cholesterol and m ...201122208089
nuclear markers reveal a complex introgression pattern among marine turtle species on the brazilian coast.surprisingly, a high frequency of interspecific sea turtle hybrids has been previously recorded in a nesting site along a short stretch of the brazilian coast. mitochondrial dna data indicated that as much as 43% of the females identified as eretmochelys imbricata are hybrids in this area (bahia state of brazil). it is a remarkable find, because most of the nesting sites surveyed worldwide, including some in northern brazil, presents no hybrids, and rare caribbean sites present no more than 2% o ...201222780882
overlapping genetic codes for overlapping frameshifted genes in testudines, and lepidochelys olivacea as special case.mitochondrial genes code for additional proteins after +2 frameshifts by reassigning stops to code for amino acids, which defines overlapping genetic codes for overlapping genes. turtles recode stops uar → trp and agr → lys (agr → gly in the marine olive ridley turtle, lepidochelys olivacea). in lepidochelys the +2 frameshifted mitochondrial cytb gene lacks stops, open reading frames from other genes code for unknown proteins, and for regular mitochondrial proteins after frameshifts according to ...201223137449
incorporating uncertainty of management costs in sensitivity analyses of matrix population models.the importance of accounting for economic costs when making environmental-management decisions subject to resource constraints has been increasingly recognized in recent years. in contrast, uncertainty associated with such costs has often been ignored. we developed a method, on the basis of economic theory, that accounts for the uncertainty in population-management decisions. we considered the case where, rather than taking fixed values, model parameters are random variables that represent the s ...201323305382
the use of spirometry to evaluate pulmonary function in olive ridley sea turtles (lepidochelys olivacea) with positive buoyancy disorders.this study utilized computed spirometry to compare the pulmonary function of two stranded olive ridley sea turtles (lepidochelys olivacea) presenting with a positive buoyancy disorder with two healthy captive olive ridley sea turtles held in a large public aquarium. pulmonary function test (pft) measurements demonstrated that the metabolic cost of breathing was much greater for animals admitted with positive buoyancy than for the normal sea turtles. positively buoyant turtles had higher tidal vo ...201324063092
primary fibroblast cultures and karyotype analysis for the olive ridley sea turtle (lepidochelys olivacea). 201424310004
the distribution and conservation status of green turtles (chelonia mydas) and olive ridley turtles (lepidochelys olivacea) on pulau pinang beaches (malaysia), 1995-2009.the green turtle (chelonia mydas) and olive ridley turtle (lepidochelys olivacea) are the only sea turtles with recorded landings in the pulau pinang coastal area. the green turtle has been the most abundant and widely distributed sea turtle in this area since it was first surveyed in 1995. statistical analysis by the pulau pinang department of fisheries on the distribution of sea turtles from 2001 through 2009 has identified pantai kerachut and telok kampi as the most strongly preferred beaches ...201224575226
fishery gear interactions from stranded bottlenose dolphins, florida manatees and sea turtles in florida, u.s.a.documenting the extent of fishery gear interactions is critical to wildlife conservation efforts, especially for reducing entanglements and ingestion. this study summarizes fishery gear interactions involving common bottlenose dolphins (tursiops truncatus truncatus), florida manatees (trichechus manatus latirostris) and sea turtles: loggerhead (caretta caretta), green turtle (chelonia mydas), leatherback (dermochelys coriacea), hawksbill (eretmochelys imbricata), kemp's ridley (lepidochelys kemp ...201424613263
rnai-mediated gene silencing in a gonad organ culture to study sex determination mechanisms in sea turtle.the autosomal sry-related gene, sox9, encodes a transcription factor, which performs an important role in testis differentiation in mammals. in several reptiles, sox9 is differentially expressed in gonads, showing a significant upregulation during the thermo-sensitive period (tsp) at the male-promoting temperature, consistent with the idea that sox9 plays a central role in the male pathway. however, in spite of numerous studies, it remains unclear how sox9 functions during this event. in the pre ...201324705165
trace elements in blood of sea turtles lepidochelys olivacea in the gulf of california, mexico.this study determined the concentrations of heavy metals in blood collected from pacific ridley sea turtles (lepidochelys olivacea) inhabiting the coast of guasave, mexico, in the gulf of california. the highest reported metal concentration in blood was zn, followed by se. of nonessential toxic metals, as was reported in higher percentage compared to cd. the concentrations of metals detected were present as follows: zn > se > mn > as > ni > cd > cu. cd concentration in blood is higher in our pop ...201424957795
patterns and inferred processes associated with sea turtle strandings in paraíba state, northeast brazil.this study analysed sea turtle strandings on the coast of paraíba state, northeastern brazil, from august 2009 to july 2010. a total of 124 strandings were recorded in this period: green turtle chelonia mydas (n = 106), hawksbill eretmochelys imbricata (n = 15), olive ridley lepidochelys olivacea (n = 2) and loggerhead caretta caretta (n = 1). of all turtles for which the curved carapace length (ccl) was measured (n = 122), only 12 individuals (9.7%) were adults. twenty individuals had synthetic ...201425166312
metals and metalloids in whole blood and tissues of olive ridley turtles (lepidochelys olivacea) from la escobilla beach (oaxaca, mexico).concentrations of eight metals and metalloids (pb, cd, cu, zn, mn, se, ni and as) were evaluated from 41 nesting females (blood) and 13 dead (tissues) olive ridley turtles (lepidochelys olivacea), a species classified as vulnerable and also listed in appendix i of the convention of international trade in endangered species (cites). the mean blood, liver and kidney lead concentration were 0.02 ± 0.01, 0.11 ± 0.08 and 0.06 ± 0.03 μ gg(-1) ww respectively, values lower than other turtle species and ...201425301056
olive ridley sea turtle hatching success as a function of the microbial abundance in nest sand at ostional, costa rica.several studies have suggested that significant embryo mortality is caused by microbes, while high microbial loads are generated by the decomposition of eggs broken by later nesting turtles. this occurs commonly when nesting density is high, especially during mass nesting events (arribadas). however, no previous research has directly quantified microbial abundance and the associated effects on sea turtle hatching success at a nesting beach. the aim of this study was to test the hypothesis that t ...201525714355
diatoms and other epibionts associated with olive ridley (lepidochelys olivacea) sea turtles from the pacific coast of costa rica.although the sea turtles have long been familiar and even iconic to marine biologists, many aspects of their ecology remain unaddressed. the present study is the first of the epizoic diatom community covering the olive ridley turtle's (lepidochelys olivacea) carapace and the first describing diatoms living on sea turtles in general, with the primary objective of providing detailed information on turtle epibiotic associations. samples of turtle carapace including the associated diatom biofilm and ...201526083535
expression of aromatase in the embryonic brain of the olive ridley sea turtle (lepidochelys olivacea), and the effect of bisphenol-a in sexually differentiated embryos.brain aromatase participates in several biological processes, such as regulation of the reproductive-endocrine axis, memory, stress, sexual differentiation of the nervous system, male sexual behavior, and brain repair. here we report the isolation and expression of brain aromatase in olive ridley sea turtle (lepidochelys olivacea) embryos incubated at male- and female-promoting temperatures (mpt and fpt, respectively), at the thermosensitive period (tsp) and the sex-differentiated period. also, ...201426154314
isolation, characterization, and antibiotic resistance of vibrio spp. in sea turtles from northwestern mexico.the aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in ojo de liebre lagoon (oll), baja california sur (bcs), mexico (pacific ocean) and the lagoon system of navachiste (lsn) and marine area of influence (mai), guasave, sinaloa (gulf of california). a total of 34 black turtles (chelonia mydas agassizii) were sampled in oll and eight black turtles and 22 olive ridley turtle ...201526161078
evidence of fluconazole-resistant candida species in tortoises and sea turtles.the aim of this study was to evaluate the antifungal susceptibility of candida spp. recovered from tortoises (chelonoidis spp.) and sea turtles (chelonia mydas, caretta caretta, lepidochelys olivacea, eretmochelys imbricata). for this purpose, material from the oral cavity and cloaca of 77 animals (60 tortoises and 17 sea turtles) was collected. the collected specimens were seeded on 2% sabouraud dextrose agar with chloramphenicol, and the identification was carried out by morphological and bioc ...201526363919
risk analysis reveals global hotspots for marine debris ingestion by sea turtles.plastic marine debris pollution is rapidly becoming one of the critical environmental concerns facing wildlife in the 21st century. here we present a risk analysis for plastic ingestion by sea turtles on a global scale. we combined global marine plastic distributions based on ocean drifter data with sea turtle habitat maps to predict exposure levels to plastic pollution. empirical data from necropsies of deceased animals were then utilised to assess the consequence of exposure to plastics. we mo ...201626365568
distribution and feeding behavior of omorgus suberosus (coleoptera: trogidae) in lepidochelys olivacea turtle nests.omorgus suberosus (fabricius, 1775) has been identified as a potential predator of the eggs of the turtle lepidochelys olivacea (eschscholtz, 1829) on one of the main turtle nesting beaches in the world, la escobilla in oaxaca, mexico. this study presents an analysis of the spatio-temporal distribution of the beetle on this beach (in areas of high and low density of l. olivacea nests over two arrival seasons) and an evaluation, under laboratory conditions, of the probability of damage to the tur ...201526422148
exogenous estradiol alters gonadal growth and timing of temperature sex determination in gonads of sea turtle.temperature sex determining species offer a model for investigating how environmental cues become integrated to the regulation of patterning genes and growth, among bipotential gonads. manipulation of steroid hormones has revealed the important role of aromatase in the regulation of the estrogen levels involved in temperature-dependent sex determination. estradiol treatment counteracts the effect of male-promoting temperature, but the resulting ovarian developmental pattern differs from that man ...201526465360
spirorchiid infection in olive ridley turtle, lepidochelys olivacea (eschscholtz, 1829) (testudines: cheloniidae), from brazil.the olive ridley turtle, lepidochelys olivacea (eschscholtz, 1829) (testudines: cheloniidae), is 1 of the 5 species of sea turtle found along the coast of brazil. little is known regarding infection by species of the family spirorchiidae in the host, as only 1 report exists. this case report describes granulomas in different tissues associated to type 1 and 3 spirorchiid eggs in 5 l. olivacea from the brazilian coast. the occurrence of the eggs was considered an incidental finding and may have c ...201626653792
asymmetry of righting reflexes in sea turtles and its behavioral correlates.the righting responses, when the animal rights itself over one side of the body after been overturned on the back, are one of the simplest ways to test for laterality, especially in lower vertebrates. in anuran amphibians unilateral preferences in righting responses correlated to the degree of the use of alternating-limb (asynchronous) movements during locomotion. turtles is one of the underrepresented vertebrate groups in the studies of laterality, while possess also different types of locomoti ...201626772421
schistosomus reflexus syndrome in olive ridley sea turtles ( lepidochelys olivacea).the olive ridley sea turtle ( lepidochelys olivacea), considered the most abundant sea turtle species, is listed as vulnerable on the international union for conservation of nature red list. the most important nesting areas are located in the eastern pacific, and congenital malformations have been previously reported in this species. the present study was conducted in a single population at el verde beach, one of the most important nesting beaches for the species in the northwestern mexican paci ...201727281016
metal contents of marine turtle eggs (chelonia mydas; lepidochelys olivacea) from the tropical eastern pacific and the implications for human health.concentrations of eight elements were measured in chelonia mydas and lepidochelys olivacea eggs collected along the pacific coast of panama. manganese (mn), iron (fe), copper (cu), zinc (zn), arsenic (as), cadmium (cd), and mercury (hg) concentrations were similar to previous reports of these species from around the world, while lead (pb) was lower than previous reports. cd posed the highest health risk to people who regularly eat the eggs, with average consumption rates leading to target hazard ...201627323656
dimorphic dna methylation during temperature-dependent sex determination in the sea turtle lepidochelys olivacea.sex determination in vertebrates depends on the expression of a conserved network of genes. sea turtles such as lepidochelys olivacea have temperature-dependent sex determination. the present work analyses some of the epigenetic processes involved in this. we describe sexual dimorphism in global dna methylation patterns between ovaries and testes of l. olivacea and show that the differences may arise from a combination of dna methylation and demethylation events that occur during sex determinati ...201627342379
environmental dynamics of red noctiluca scintillans bloom in tropical coastal waters.an intense bloom of red noctiluca scintillans (ns) occurred off the rushikulya estuarine region along the east coast of india, an important site for mass nesting events of the vulnerable olive ridley sea turtle. at its peak, densities of ns were 3.3×10(5) cells-l(-1), with low relative abundance of other phytoplankton. the peak bloom coincided with high abundance of gelatinous planktivores which may have facilitated bloom development by their grazing on other zooplankton, particularly copepods. ...201627449626
trans-6-hexadecenoic acid in the atlantic leatherbackdermochelys coriacea coriacea l. and other marine turtles.depot fat from the atlantic leatherback turtle (dermochelys coriacea coriacea l.) was shown to contain ≈3% oftrans-6-hexadecenoic acid. structural details were elucidated through comparative aspects of isolation techniques, nmr, ir, hydrogenation, oxidative fission, etc., and confirmed by similarity of properties with those of a sample of fatty acid of this structure isolated from the seed oil ofpicramnia sellowii. one additional leather-back turtle oil sample, and depot fat from two other marin ...197027520952
levels of perfluorinated acids (pfcas) in different tissues of lepidochelys olivacea sea turtles from the escobilla beach (oaxaca, mexico).lepidochelys olivacea is the most abundant and globally distributed sea turtle species in the world and thus, monitoring this species for persistent organic pollutants, such as perfluorinated chemicals, is fundamental for their protection. this study was the first to evaluate the occurrence of five pfcas (pfoa, pfna, pfda, pfuna, pfdoa) in liver and blood samples of olive ridley turtle population from the escobilla beach (oaxaca, mexico). pfda and pfuna were the predominant pfcs in blood samples ...201627522287
isotopic effects of different preservation methods on scales of olive ridley sea turtles (lepidochelys olivacea) from the mexican central pacific.stable isotope analysis can be used to obtain information on olive ridley sea turtles in the mexican central pacific (mcp). tissue samples such as scale, muscle, and blood are usually not analyzed immediately and are preserved in different substances such as ethanol, formalin, sodium chloride, the ideal being liquid nitrogen. due to logistical reasons, that preservation method cannot always be used. the objective of the present study was to evaluate the efficiency of dmso as a preservation agent ...201627605493
identification and evaluation of semiochemicals for the biological control of the beetle omorgus suberosus (f.) (coleoptera: trogidae), a facultative predator of eggs of the sea turtle lepidochelys olivacea (eschscholtz).the beetle omorgus suberosus (f.) is a facultative predator of eggs of the olive ridley turtle lepidochelys olivacea (eschscholtz). laboratory and field investigations were conducted in order to characterize volatile attractants of o. suberosus and to explore the potential for application of these volatiles in a selective mass trapping method. headspace sorptive extraction (hsse) coupled to thermo-desorption gas chromatography-mass spectrometry (td-gc-ms) analysis of the volatile constituents fr ...201728192472
examining the role of transmission of chelonid alphaherpesvirus 5.marine turtle fibropapillomatosis (fp) is a devastating neoplastic disease characterized by single or multiple cutaneous and visceral fibrovascular tumors. chelonid alphaherpesvirus 5 (chhv5) has been identified as the most likely etiologic agent. from 2010 to 2013, the presence of chhv5 dna was determined in apparently normal skin, tumors and swab samples (ocular, nasal and cloacal) collected from 114 olive ridley (lepidochelys olivacea) and 101 green (chelonia mydas) turtles, with and without ...201728512730
are thermal barriers "higher" in deep sea turtle nests?thermal tolerances are affected by the range of temperatures that species encounter in their habitat. daniel janzen hypothesized in his "why mountain passes are higher in the tropics" that temperature gradients were effective barriers to animal movements where climatic uniformity was high. sea turtles bury their eggs providing some thermal stability that varies with depth. we assessed the relationship between thermal uniformity and thermal tolerance in nests of three species of sea turtles. we c ...201728545092
developmental cardiovascular physiology of the olive ridley sea turtle (lepidochelys olivacea).our understanding of reptilian cardiovascular development and regulation has increased substantially for two species the american alligator (alligator mississippiensis) and the common snapping turtle (chelydra serpentina) during the past two decades. however, what we know about cardiovascular maturation in many other species remains poorly understood or unknown. embryonic sea turtles have been studied to understand the maturation of metabolic function, but these studies have not addressed the ca ...201728642099
the current situation of inorganic elements in marine turtles: a general review and meta-analysis.inorganic elements (pb, cd, hg, al, as, cr, cu, fe, mn, ni, se and zn) are present globally in aquatic systems and their potential transfer to marine turtles can be a serious threat to their health status. the environmental fate of these contaminants may be traced by the analysis of turtle tissues. loggerhead turtles (caretta caretta) are the most frequently investigated of all the sea turtle species with regards to inorganic elements, followed by green turtles (chelonia mydas); all the other sp ...201728688307
assessing fukushima-derived radiocesium in migratory pacific predators.the 2011 release of fukushima-derived radionuclides into the pacific ocean made migratory sharks, teleosts, and marine mammals a source of speculation and anxiety regarding radiocesium (134+137cs) contamination, despite a lack of actual radiocesium measurements for these taxa. we measured radiocesium in a diverse suite of large predators from the north pacific ocean and report no detectable (i.e., ≥ 0.1 bq kg-1dry wt) fukushima-derived134cs in all samples, except in one olive ridley sea turtle ( ...201728714301
persistent organic pollutants in fat of three species of pacific pelagic longline caught sea turtles: accumulation in relation to ingested plastic marine debris.in addition to eating contaminated prey, sea turtles may be exposed to persistent organic pollutants (pops) from ingesting plastic debris that has absorbed these chemicals. given the limited knowledge about pops in pelagic sea turtles and how plastic ingestion influences pop exposure, our objectives were to: 1) provide baseline contaminant levels of three species of pelagic pacific sea turtles; and 2) assess trends of contaminant levels in relation to species, sex, length, body condition and cap ...201828806556
17β-estradiol modulates cell proliferation of medullary cords during ovarian differentiation of the lepidochelys olivacea sea turtle.in turtles undergoing temperature sex determination (tsd), bipotential gonads express sox9 in medullary cords at both female- (fpt) and male-producing temperatures (mpt). subsequently, when the sex fate of medullary cords becomes dimorphic, at fpt, sox9 is downregulated, whereas at mpt, its expression is maintained. medullary cords in the ovary turn into ovarian lacuna, whereas in the testis they differentiate as seminiferous cords. when embryos of lepidochelys olivacea sea turtle are incubated ...201728893547
p-nitrophenyl acetate esterase activity and cortisol as biomarkers of metal pollution in blood of olive ridley turtles (lepidochelys olivacea).this study was designed to determine the concentrations of p-nitrophenyl acetate esterase activity (ea) and cortisol in serum of marine olive ridley turtles (lepidochelys olivacea) from a mexican pacific population ("la escobilla" beach) and to evaluate the possible relationship of inorganic elements with these biomarkers. ea, cortisol, and selected chemical elements (cd, pb, ti, sr, se, al, as, and zn) were measured in the blood of 44 sea turtles from the eastern pacific (southeast mexico). ser ...201729043390
molecular oxidative stress markers in olive ridley turtles (lepidochelys olivacea) and their relation to metal concentrations in wild populations.due to their longevity and extensive migration areas, marine turtles are able to accumulate diverse contaminants over many years and as a consequence they represent an interesting bioindicator species for marine ecosystem pollution. metals provoke toxicological effects in many aquatic animal species, but marine turtles have been under-investigated in this area. thus, we have determined the presence of certain inorganic elements (as, cd, cu, ni, pb, se and zn) in olive ridley turtles (lepidochely ...201829073523
quantifying nearshore sea turtle densities: applications of unmanned aerial systems for population assessments.although sea turtles face significant pressure from human activities, some populations are recovering due to conservation programs, bans on the trade of turtle products, and reductions in bycatch. while these trends are encouraging, the status of many populations remains unknown and scientific monitoring is needed to inform conservation and management decisions. to address these gaps, this study presents methods for using unmanned aerial systems (uas) to conduct population assessments. using a f ...201729255157
carapace asymmetry: a possible biomarker for metal accumulation in adult olive ridleys marine turtles?the olive ridley marine turtle (lepidochelys olivacea) is characterized by individual morphological variability in the number and shape of scutes. the influence of pollutants on developmental instability and one of its consequences, the asymmetry of individuals, has been demonstrated in several species, especially invertebrates and some birds. however, the use of this asymmetry as a biomarker of contamination in adult individuals has never been explored. we developed an index to quantify develop ...201829680573
isolation by environment in the highly mobile olive ridley turtle (lepidochelys olivacea) in the eastern pacific.spatial and temporal scales at which processes modulate genetic diversity over the landscape are usually overlooked, impacting the design of conservation management practices for widely distributed species. we examine processes shaping population divergence in highly mobile species by re-assessing the case of panmixia in the iconic olive ridley turtle from the eastern pacific. we implemented a biophysical model of connectivity and a seascape genetic analysis based on nuclear dna variation of 634 ...201829720414
expression of human mutant cyclin dependent kinase 4, cyclin d and telomerase extends the life span but does not immortalize fibroblasts derived from loggerhead sea turtle (caretta caretta).conservation of the genetic resources of endangered animals is crucial for future generations. the loggerhead sea turtle (caretta caretta) is a critically endangered species, because of human hunting, hybridisation with other sea turtle species, and infectious diseases. in the present study, we established primary fibroblast cell lines from the loggerhead sea turtle, and showed its species specific chromosome number is 2n = 56, which is identical to that of the hawksbill and olive ridley sea tur ...201829925962
conjunctival bacterial flora and antimicrobial susceptibility of captive and free-living sea turtles in brazil.to describe the aerobic conjunctival bacterial flora of 3 especies of free-living and under human care sea turtles and determine its antimicrobial susceptibility in vitro.201929953719
blood biochemistry of olive ridley (lepidochelys olivacea) sea turtles foraging in northern sinaloa, mexico.blood parameters provide an excellent tool to evaluate the health status of wildlife. however, there are few studies about health parameters of sea turtles in mexico. for olive ridley turtles (lepidochelys olivacea), no information was available to establish the health baseline for the species. the objective of this study was to establish reference blood biochemistry values for olive ridley turtles in the northern sinaloa foraging area. between 2013 and 2015, 82 olive ridley turtles were capture ...201830044783
methylation status of the putative pax6 promoter in olive ridley sea turtle embryos with eye defects: an initial approach.normal development involves the interplay of genetic and epigenetic regulatory mechanisms. pax6 is an eye-selector factor responsible for initiating the regulatory cascade for the development of the eyes. for the olive ridley sea turtle (lepidochelys olivacea), a threatened species, eye malformations have been reported. in order to study the dna methylation status of the putative promoter of the pax6 gene in embryos with ocular malformations, an exploratory study was carried out in which dna was ...201830110613
monitoring data of marine turtles on the togolese coast during 2012-2013.this dataset contains information on the presence and distribution of sea turtles in togo. observations were carried out through a network of ten ecoguards (local guides), facilitated by five fishermen, and coordinated by a field technician, all under the supervision of a scientific coordinator. data on the occurrence or direct observation of sea turtles on the togolese coast from september 2012 to august 2013 is presented based on 740 occurrences.201830123024
relationship between plasma biochemistry values and metal concentrations in nesting olive ridley sea turtles.a hundred nesting olive ridley turtles were sampled to determine biochemical parameters (alp, ast, alt, creatinine, albumin, cholesterol, glucose, proteins, triglycerides, urea, and p-nitrophenyl acetate esterase activity). esterase activity (ea) is a new biomarker very sensitive to metals. most of the samples showed detectable levels. we also analyzed the concentration of 11 inorganic elements (as, cd, cr, cu, mn, ni, pb, sr, ti, se, and zn), some of them previously reported with very high conc ...201830377965
presence of chelonid herpesvirus 5 (chhv5) in sea turtles in northern sinaloa, mexico.the presence of fibropapilloma and its associated chelonid herpesvirus 5 (chhv5) was assessed in 82 wild sea turtles. olive ridley turtles lepidochelys olivacea (n = 58) were caught in the pelagic area of marine influence (ami) (off the coast of guasave, sinaloa), and black turtles chelonia mydas agassizii (n = 24) were captured in the navachiste lagoon system. the apparent physical condition was evaluated as 'good' or 'poor' by physical examination. the population structure and general health s ...201930628576
supernumerary scutes verify a segment-dependent model of the horny shell development in turtles.turtle horny shell has a scute pattern, which is conservative through evolution and across species. the discovery of epidermal placodes as the scute primordia and their strict topographical association to the somites of the turtle embryo suggested a new interpretation of the developmental mechanism of the scute pattern. here, we tested the hypothesis that horny scutes develop from a mosaic of placodes corresponding exactly to the paths of myoseptae, with vertebral and pleural scutes developing s ...201931198986
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