| tangential organization of olfactory, association, and commissural projections to olfactory cortex in a species of reptile (trionyx spiniferus), bird (aix sponsa), and mammal (tupaia glis). | small amounts of tritiated leucine were injected into the olfactory bulb or anterior olfactory cortex of softshell turtles, wood ducks, and tree shrews in order to compare quantitatively the laminar distribution of olfactory bulb, association, and commissural projections to olfactory cortex. in all three species, a similar colaminar distribution of olfactory and association projections was found: the olfactory projections are restricted to the superficial cortical layer ia, while the association ... | 1984 | 6535631 |
| detection of salmonellae in different turtle species within a headwater spring ecosystem. | sediments and water from the slough arm of spring lake, the headwaters of the san marcos river, texas, usa, as well as swabs from biofilms on carapaces and from the cloacae of 18 common musk turtles (sternotherus odoratus), 21 red-eared sliders (trachemys scripta elegans), nine texas river cooters (pseudemys texana), one snapping turtle (chelydra serpentina serpentina), and three guadalupe spiny soft-shell turtles (apalone spinifera guadalupensis), caught at the same site, were analyzed for salm ... | 2008 | 18436690 |
| redescription of testudotaenia testudo (magath, 1924) (eucestoda: proteocephalidea), a parasite of apalone spinifera (le sueur) (reptilia: trionychidae) and amia calva l. (pisces: amiidae) in north america and erection of the testudotaeniinae n. subfam. | testudotaenia testudo (magath, 1924) is redescribed from the intestine of the softshell turtle apalone spinifera (le sueur) (trionychidae) and the bowfin amia calva linnaeus (amiidae) from reelfoot lake, tennessee, united states. a new subfamily, the testudotaeniinae, is erected. the new taxon differs from all proteocephalidean subfamilies in the position of the genital organs in relation to the longitudinal internal musculature, i.e. the testes are cortical, rarely medullary; the ovary is partl ... | 2009 | 19337859 |
| sepsis and disseminated intravascular coagulation in an eastern spiny softshell turtle (apalone spinifera spinifera) with acute mycobacteriosis. | an adult, captive eastern spiny softshell turtle (apalone spinifera spinifera) was examined for a 4-day history of lethargy and plastron discoloration. the turtle was obtunded and had pale mucous membranes, hemorrhagic nasal discharge, and petechiae on all limbs. the turtle was euthanized due to its grave condition. necropsy revealed hemorrhagic coelomic effusion, petechiae on the serosal surfaces of the intestinal tract, and bilaterally hemorrhagic lungs. histologic examination revealed numerou ... | 2009 | 19746876 |
| osteology and skeletal development of apalone spinifera (reptilia: testudines: trionychidae). | despite considerable attention that other groups of reptiles have received, few descriptions of the development and sequences of chondrification and ossification of the entire skeleton of turtles exist. herein, the adult skeleton of the spiny softshell turtle, apalone spinifera (testudines: trionychidae), is described; this description forms a basis of comparison for the embryonic skeleton and its ontogenesis. descriptions are made on the basis of cleared and double-stained embryos and dry skele ... | 2003 | 12616574 |
| water-vapor conductance of testudinian and crocodilian eggs (class reptilia). | flexible-shelled eggs of snapping turtles (chelydra serpentina) have conductances to water vapor that are 55 times higher than predicted for avian eggs of similar size, whereas rigid-shelled eggs of softshell turtles (trionyx spiniferus) and american alligators (alligator mississippiensis) have conductances that are only five times higher than expected for comparable eggs of birds. the differences between empirical and predicted values result from the much higher effective pore areas in reptilia ... | 1979 | 515558 |
| transcriptomic responses to environmental temperature by turtles with temperature-dependent and genotypic sex determination assessed by rnaseq inform the genetic architecture of embryonic gonadal development. | vertebrate sexual fate is decided primarily by the individual's genotype (gsd), by the environmental temperature during development (tsd), or both. turtles exhibit tsd and gsd, making them ideal to study the evolution of sex determination. here we analyze temperature-specific gonadal transcriptomes (rna-sequencing validated by qpcr) of painted turtles (chrysemys picta tsd) before and during the thermosensitive period, and at equivalent stages in soft-shell turtles (apalone spinifera-gsd), to tes ... | 2017 | 28296881 |
| levisunguis subaequalis n. g., n. sp., a tongue worm (pentastomida: porocephalida: sebekidae) infecting softshell turtles, apalone spp. (testudines: trionychidae) in the southeastern united states. | a new tongue worm (pentastomida) belonging to the sebekidae sambon, 1922 (porocephaloidea sambon, 1922) is described based on exemplars collected from softshell terrapins apalone spinifera aspera (agassiz) and apalone ferox (schneider) in the southeastern united states; a new genus is erected to accommodate the new species. the new species belongs in the sebekidae because adults possess four simple hooks arranged in a trapezoid pattern on the ventral surface of the cephalothorax, a mouth opening ... | 2014 | 24395574 |
| ultrastructural immunolocalization of alpha-keratins and associated beta-proteins (beta-keratins) suggests a new interpretation on the process of hard and soft cornification in turtle epidermis. | the epidermis of soft-shelled and hard-shelled turtles has been compared to determine the origin of the different cornification. immunolocalization of acidic alpha-keratin (ak2) of 45-50 kda in tonofilaments of the epidermis in apalone spinifera and absence in the corneous layer where desquamating corneocytes are present supports the biochemical data. corneocytes shows a weak to absent immunolabeling for beta-proteins (formerly beta-keratins) of 14-16 kda while sparse immunolabeled corneous gran ... | 2013 | 23958576 |
| molecular characterization of alpha-keratins in comparison to associated beta-proteins in soft-shelled and hard-shelled turtles produced during the process of epidermal differentiation. | the tough corneous layer in the carapace and plastron of hard-shelled turtles derives from the accumulation of keratin-associated beta-proteins (kabetaps, formerly called beta-keratins) while these proteins are believed to be absent in soft-shelled turtles. our bioinformatics and molecular study has instead shown that the epidermis of the soft-shelled turtle apalone spinifera expresses beta-proteins like or even in higher amount than in the hard-shelled turtle pseudemys nelsoni. the analysis of ... | 2013 | 23794440 |
| biomolecular identification of beta-defensin-like peptides from the skin of the soft-shelled turtle apalone spinifera. | numerous bacteria are frequently observed in the superficial corneocytes forming the corneous layer of the soft-shelled turtle apalona spinifera. the resistance to bacterial penetration through the living epidermis in this turtle suggests the presence of an antimicrobial barrier, possibly derived from the presence of anti-microbial peptides in the epidermis. four beta-defensin-like peptides, named as-bd-1 to 4, have been characterized from skin tissues using molecular and bioinformatics methods. ... | 2013 | 23554337 |
| a zz/zw microchromosome system in the spiny softshell turtle, apalone spinifera, reveals an intriguing sex chromosome conservation in trionychidae. | reptiles display a wide diversity of sex-determining mechanisms ranging from temperature-dependent sex determination (tsd) to genotypic sex determination (gsd) with either male (xy) or female (zw) heterogamety. despite this astounding variability, the origin, structure, and evolution of sex chromosomes remain poorly understood. in turtles, tsd is purportedly ancestral while gsd arose multiple times independently. here we test whether independent (xy or zw) or morphologically divergent heterogame ... | 2013 | 23512312 |
| anatomy of the fully formed chondrocranium of emydura subglobosa (chelidae): a pleurodiran turtle. | the chondrocranium is a cartilaginous structure that forms around and protects the brain and sensory organs of the head. through ontogeny, this skeletal structure may become more elaborate, remodeled and reabsorbed, and/or ossified. though considerable attention has been given to the formation of the chondrocranium and a great amount of data has been gathered on the development of this structure among many craniates, the anatomy of this structure in turtles often is neglected. we describe the ma ... | 2013 | 22972700 |
| skeletal development in the chinese soft-shelled turtle pelodiscus sinensis (testudines: trionychidae). | we investigated the development of the whole skeleton of the soft-shelled turtle pelodiscus sinensis, with particular emphasis on the pattern and sequence of ossification. ossification starts at late tokita-kuratani stage (tk) 18 with the maxilla, followed by the dentary and prefrontal. the quadrate is the first endoskeletal ossification and appears at tk stage 22. all adult skull elements have started ossification by tk stage 25. plastral bones are the first postcranial bones to ossify, whereas ... | 2009 | 19530096 |
| formation and ossification of limb elements in trachemys scripta and a discussion of autopodial elements in turtles. | though sequences of formation and ossification of bony elements have been described for many taxa, controversy surrounds the formation of limb elements in turtles. three hypotheses for patterns of formation of autopodial elements have been proposed, differing primarily in the origin of distal carpal/tarsal 3, the digital arch, and centrale 4. patterns of formation and ossification of limb elements are described for trachemys scripta. these patterns are compared to similar data for representative ... | 2008 | 18624573 |
| survival and physiological responses of hatchling blanding's turtles (emydoidea blandingii) to submergence in normoxic and hypoxic water under simulated winter conditions. | overwintering habits of hatchling blanding's turtles (emydoidea blandingii) are unknown. to determine whether these turtles are able to survive winter in aquatic habitats, we submerged hatchlings in normoxic (155 mmhg po2) and hypoxic (6 mmhg po2) water at 4 degrees c, recording survival times and measuring changes in key physiological variables. for comparison, we simultaneously studied hatchling softshell (apalone spinifera) and snapping (chelydra serpentina) turtles, which are known to overwi ... | 2016 | 15887082 |
| effect of graded hypoxic and acidotic stress on contractile force of heart muscle from hypoxia-tolerant and hypoxia-intolerant turtles. | previous studies have shown that isometric contractile force of in vitro cardiac muscle from the anoxia-tolerant painted turtle, chrysemys picta bellii, decreases when anoxic and when acidotic. this study sought to define the thresholds for these responses in the isolated ventricular strips of the painted turtle and in the anoxia-intolerant softshell turtles, apalone spinifera. the ventricular strips were exposed to hco3- ringer's solution equilibrated at p(o2) 156, 74, 37, 19, and 0 mmhg (45 mi ... | 2005 | 15828014 |
| relative contributions of organochlorine contaminants, parasitism, and predation to reproductive success of eastern spiny softshell turtles (apalone spiniferus spiniferus) from southern ontario, canada. | we examined hatching success, predation rates, rates of parasitism, sex ratio, and egg viability in eggs of the eastern spiny softshell (apalone spiniferus spiniferus), a threatened species in canada. eggs were monitored from three populations, located at thames river, rondeau provincial park, and the long point national wildlife area, in southern ontario, canada in 1998. concurrently, we measured organochlorine pesticides, pcbs, dibenzo-p-dioxins and furans from eggs from the same nests. contam ... | 2013 | 12739873 |
| hibernation in freshwater turtles: softshell turtles (apalone spinifera) are the most intolerant of anoxia among north american species. | softshell turtles (apalone spinifera) were submerged at 3 degrees c in anoxic or normoxic water. periodically, blood po(2), pco(2), ph, plasma [cl(-)], [na(+)], [k(+)], total ca, total mg, lactate, glucose, and osmolality were measured; hematocrit and body mass determined; and blood [hco(3)(-)] calculated. on day 14 of anoxic submergence, five of eight softshell turtles were dead, one died immediately after removal, and the remaining two showed no signs of life other than a heartbeat. after 11 d ... | 2003 | 12687397 |
| staging criteria for embryos of the spiny softshell turtle, apalone spinifera (testudines: trionychidae). | previous work describing the embryonic stages of turtle development has not included members of the highly derived trionychid turtles. staging criteria are described for the spiny softshell turtle (apalone spinifera) to facilitate comparisons between phylogenetically distant taxa of turtles. embryonic development in a. spinifera is placed in the context of the widely used sequence of yntema stages. novel features are included in the descriptions of staging criteria for stages 13-26. comparisons ... | 2002 | 12386898 |
| comparative kinematics of the forelimb during swimming in red-eared slider (trachemys scripta) and spiny softshell (apalone spinifera) turtles. | softshell turtles (family trionychidae) possess extensive webbing between the digits of the manus, suggesting that the forelimb may serve as an effective thrust generator during aquatic locomotion. however, the hindlimb has previously been viewed as the dominant propulsive organ in swimming freshwater turtles. to evaluate the potential role of the forelimb in thrust production during swimming in freshwater turtles, we compared the forelimb morphology and three-dimensional forelimb kinematics of ... | 2001 | 11606600 |
| sexual differentiation in the spiny softshell turtle (apalone spinifera), a species with genetic sex determination. | it is hypothesized on the basis of sex determination theory that species exhibiting genetic sex determination (gsd) may undergo sexual differentiation earlier in development than species with environmental sex determination (esd). most turtle species exhibit a form of esd known as temperature-dependent sex determination (tsd), and in such species the chronology of sex differentiation is well studied. apalone spinifera is a species of softshell turtle (trionychidae) that exhibits gsd. we studied ... | 2001 | 11471149 |
| lactic acid buffering by bone and shell in anoxic softshell and painted turtles. | we tested two hypotheses: first, that the inferior anoxia tolerance of the softshell turtle, apalone spinifera, compared to the western painted turtle, chrysemys picta bellii, is related to its less mineralized shell, and second, that turtle bone, like its shell, stores lactate during prolonged anoxia. lactate concentrations of blood, hindlimb bone, and shell were measured on normoxic apalone and chrysemys and after anoxic submergence at 10 degrees c for 2 and 9 d, respectively. blood and shell ... | 2016 | 10893168 |
| a cystic calculus from a wild western spiny softshell turtle (apalone [trionyx] spiniferus hartwegi). | during a postmortem examination of a western spiny softshell turtle (apalone [trionyx] spiniferus hartwegi), a calculus (24 x 21 x 12-mm) with a dry weight of approximately 5 g was discovered in the urinary bladder. chemically, the calculus was a mixture of apatite (basic calcium phosphate), struvite (magnesium ammonium phosphate hexahydrate), and unidentifiable crystals. this is the first report of a cystic calculus in a wild chelonian. | 1998 | 9809613 |
| spiroxys contorta (nematoda: spirurida) in gastric granulomas of apalone spinifera pallida (reptilia: testudines). | non-caseating granulomas containing larval spirurid nematodes (spiroxys contorta) were observed in the gastric submucosa and muscularis externa of two pallid spiny softshells (apalone spinifera pallida) from northcentral texas (usa). in early granulomas, nematodes were not surrounded by a fibrous capsule but in older, mature granulomas, a fibrous capsule was present. granulomas without nematodes also were present. | 1993 | 8355361 |
| three new species of eimeria (apicomplexa: eimeriidae) from apalone spinifera pallidus (testudines: trionychidae) in texas, with a redescription of e. amydae. | three new species of eimeria are described from pallid spiny softshells, apalone spinifera pallidus, collected in north-central texas. oocysts of eimeria spinifera n. sp. were found in the feces of 3/9 (33%) turtles and are subspheroid, ellipsoid, or pear-shaped, 16.3 x 14.0 (14-19 x 12-18) microns, with a thin, single-layered wall; shape index 1.2 (1.1-1.3). a micropyle is absent, but an oocyst residuum is present; polar granule present in 16% of the oocysts. sporocysts are elongate-ovoid, 10.3 ... | 1990 | 2380856 |
| the viability of nearctic freshwater turtles submerged in anoxia and normoxia at 3 and 10 degrees c. | survival times of temperature-acclimated freshwater turtles submerged in normoxic and anoxic water were determined. juvenile chrysemys scripta from alabama and adult chrysemys picta bellii from wisconsin exhibited the maximal survival times of the 10 species and subspecies investigated, both being able to survive at least a half-year of submergence at 3 degrees c in normoxic water. minimal viability was exhibited by sternotherus odoratus and trionyx spiniferus submerged in anoxia at 10 degrees c ... | 1985 | 2863050 |
| additional notes on the coccidian parasites of the soft-shell turtle, trionyx spiniferus le sueur, in iowa, with a description of eimeria vesicostieda sp. n. | oocysts of eimeria dericksoni roudabush, eimeria mascoutini wacha & christiansen, and eimeria vesicostieda sp. n. were isolated from the spiny soft-shell turtle, trionyx spiniferus lesueur, in iowa. the sporulated oocysts of e. dericksoni are redescribed to include, for the first time, the dimensions of the sporocysts (6.0-8.5 x 3.0 5.0 micrometer) ant the structural appearance of the stieda body (thinly convex); the oocysts of e. vesicostieda are newly described as being thick-walled, narrowly ... | 1977 | 915839 |
| revision and new species of vasotrema stunkard, 1926 (digenea: schistosomatoidea): turtle blood flukes of north american softshell turtles (testudines: trionychidae: apalone spp.). | gulf coast spiny softshell turtles, apalone spinifera aspera (agassiz, 1857), (testudines: trionychidae) from canoe lake (33°47'56.16"n, 86°29'25.02"w; springville, alabama, usa) and round lake (32°41'50.91"n, 87°14'30.39"w; perry lakes state park, marion, alabama, usa) were infected by vasotrema robustum stunkard, 1928, vasotrema longitestis byrd, 1939, and vasotrema rileyae n. sp. the new species differs from its congeners by having papillate suckers, a short testis, an ovary dextral to the ov ... | 2017 | 28639473 |
| chromosomal context affects the molecular evolution of sex-linked genes and their autosomal counterparts in turtles and other vertebrates. | sex chromosomes evolve differently from autosomes because natural selection acts distinctly on them given their reduced recombination and smaller population size. various studies of sex-linked genes compared with different autosomal genes within species support these predictions. here, we take a novel alternative approach by comparing the rate of evolution between subsets of genes that are sex-linked in selected reptiles/vertebrates and the same genes located in autosomes in other amniotes. we r ... | 2017 | 29036698 |
| testing phylogenetic implications of eggshell characters in side-necked turtles (testudines: pleurodira). | amniote egg and eggshell morphology is a rich source of characters to link aspects of reproductive biology with systematics. extensive work concerning both anatomy and phylogenetic assignability has been done on fossil bird and dinosaur eggs, but little is known for extant sauropsids. the utility of eggshell characters for phylogenetic analyses is tested and discussed for extant side-necked turtles (pleurodira), and the diversity of egg ultrastructure is examined in several species. egg gross mo ... | 2006 | 16600581 |
| morphometric data for five freshwater turtles in south, central, and west texas. | from 2008 to 2013, we sampled freshwater turtle populations at 66 sites in south, central, and west texas, usa. sampling sites included ponds, lakes, resacas (oxbow lakes), canals, and rivers. we sampled turtle populations using baited hoop nets (66 sites) and basking traps (3 sites), and captured turtles by hand opportunistically in terrestrial habitat. we measured carapace length and width, plastron length and width, body depth, and weight of captured turtles. excluding recaptures, we measured ... | 2020 | 32195296 |
| effect of acclimation temperature and substrate type on selected temperature, movement and activity of juvenile spiny softshell turtles (apalone spinifera) in an aquatic thermal gradient. | in some turtle species, temperature selection may be influenced by environmental conditions, including acclimation temperature and substrate quality. these factors may be particularly important for softshell turtles that are highly aquatic and often thermoregulate by burying in the substrate in shallow water microhabitats. we tested for effects of acclimation temperature (22 °c or 27 °c) and substrate type (sand or gravel) on the selected temperature and movement patterns of 20 juvenile spiny so ... | 2020 | 33077122 |
| molecular and histopathological data on levisunguis subaequalis curran, overstreet, collins & benz, 2014 (pentastomida: eupentastomida: porocephalida: porocephaloidea: sebekidae: sebekinae) from gambusia affinis in alabama, usa. | levisunguis subaequalis curran, overstreet, collins & benz, 2014 , was recently described from the lungs of the definitive hosts, softshell turtles, apalone ferox (schneider, 1783), and apalone spinifera aspera (agassiz, 1857) as well as the viscera of an intermediate host, the western mosquitofish, gambusia affinis (baird and girard, 1853). however, the original account lacked molecular data. furthermore, histological examination of infected host tissues in the original account of l. subaequali ... | 2019 | 31742484 |
| comparative mitogenomic and phylogenetic analysis of apalone spinifera and apalone ferox (testudines: trionychidae). | the soft-shell turtles apalone spinifera (as) and apalone ferox (af) are two important economic species. af is found in the yellow river of china, and is a confirmed member of the trionychidae family. however, the classification of as was in dispute. mitochondrial genomes (mitogenomes) have been widely used for species identification, as well as population and phylogenetic analysis. in order to understand the phylogenetic and mitogenomic features of as and af, the complete mitogenomes were seque ... | 2019 | 30887216 |
| skin structure and cornification proteins in the soft-shelled turtle trionyx spiniferus. | in contrast to most chelonians, the fully aquatic soft-shelled turtles have a smooth, unscaled, and pliable shell. the skin of the shell, tail, limbs, and neck of juveniles of trionyx spiniferus has been studied by ultrastructural, immunocytochemical, and immunoblotting methods. the epidermis of the carapace and plastron has a thick corneous layer composed of alpha-corneocytes surrounded by a cornified cell envelope. the softer epidermis is similar to that of the shell but the epidermis and corn ... | 2006 | 16600580 |
| patterns of nitrogen excretion by embryonic softshell turtles (trionyx spiniferus) developing in cleidoic eggs. | embryonic softshell turtles develop inside eggs exchanging little, if any, liquid water with the nest environment. despite the consequent restriction on availability of water to support development, embryos convert most of the ammonia released in catabolism of proteins into soluble urea rather than insoluble urate, and thereby commit a portion of their limited reserve of water to serve as solvent for metabolic wastes. this finding is contrary to expectations from prior studies of cleidoic eggs. | 1983 | 17736654 |
| structure of the shell and tertiary membranes of eggs of softshell turtles (trionyx spiniferus). | eggs of the turtle trionyx spiniferus are rigid, calcareous spheres averaging 2.5 cm in diameter. the eggshell is morphologically very similar to avian eggshells. the outer crystalline layer is composed of roughly columnar aggregates, or shell units, of calcium carbonate in the aragonite form. each shell unit tapers to a somewhat conical tip at its base. interior to the crystalline layer are two tertiary egg membranes: the outer shell membrane and the inner shell membrane. the outer shell membra ... | 1979 | 30205627 |