| tick (amblyomma chabaudi) infestation of endemic tortoises in southwest madagascar and investigation of tick-borne pathogens. | little is known about the role of endemic ticks as vectors for bacterial and protozoan pathogens for animals and humans in madagascar and their interaction in anthropogenic habitats where humans, their livestock and native malagasy species (vectors and hosts) come into more frequent contact than in natural forest ecosystems. the aims of the study were (1) to test whether habitat degradation is associated with increased infestation of tortoises by ticks and (2) to investigate whether ticks carrie ... | 2016 | 26724898 |
| stress response to handling is short lived but may reflect personalities in a wild, critically endangered tortoise species. | we investigated the acute stress response associated with animal personalities by measuring plasma glucocorticoids throughout handling and collected ~2 years of movement and behavioural data in a wild, critically endangered animal, astrochelys radiata (radiated tortoise). to determine whether our standard, brief conscientious handling procedures induce a stress response in our target species, we applied a stressor by way of initial animal processing and deployment of telemetry equipment. during ... | 2017 | 28360999 |
| hematological and pathological features of massive hepatic necrosis in two radiated tortoises (astrochelys radiata). | two radiated tortoises (astrochelys radiata) exhibited anorexia and hypokinesia. in both cases, hematological and serum biochemical examinations revealed high alkaline phosphatase levels, moderately high aspartate aminotransferase levels and white blood cell counts approximately within the normal range. despite being treated, the tortoises died 9 and 43 days after the first clinical examination. gross pathological examinations revealed that the livers of both animals were extremely swollen and c ... | 2017 | 27746414 |
| chelonian perivitelline membrane-bound sperm detection: a new breeding management tool. | perivitelline membrane (pvm)-bound sperm detection has recently been incorporated into avian breeding programs to assess egg fertility, confirm successful copulation, and to evaluate male reproductive status and pair compatibility. due to the similarities between avian and chelonian egg structure and development, and because fertility determination in chelonian eggs lacking embryonic growth is equally challenging, pvm-bound sperm detection may also be a promising tool for the reproductive manage ... | 2016 | 26890048 |
| assessing the potential to restore historic grazing ecosystems with tortoise ecological replacements. | the extinction of large herbivores, often keystone species, can dramatically modify plant communities and impose key biotic thresholds that may prevent an ecosystem returning to its previous state and threaten native biodiversity. a potentially innovative, yet controversial, landscape-based long-term restoration approach is to replace missing plant-herbivore interactions with non-native herbivores. aldabran giant (aldabrachelys gigantea) and madagascan radiated (astrochelys radiata) tortoises, t ... | 2013 | 23773124 |
| the welfare implications of using exotic tortoises as ecological replacements. | ecological replacement involves the introduction of non-native species to habitats beyond their historical range, a factor identified as increasing the risk of failure for translocations. yet the effectiveness and success of ecological replacement rely in part on the ability of translocatees to adapt, survive and potentially reproduce in a novel environment. we discuss the welfare aspects of translocating captive-reared non-native tortoises, aldabrachelys gigantea and astrochelys radiata, to two ... | 2012 | 22724012 |
| microsatellite analyses provide evidence of male-biased dispersal in the radiated tortoise astrochelys radiata (chelonia: testudinidae). | dispersal is a major force in shaping the genetic structure and dynamics of species; thus, its understanding is critical in formulating appropriate conservation strategies. in many species, sexes do not face the same evolutionary pressures, and consequently dispersal is often asymmetrical between males and females. this is well documented in birds and mammals but has seldom been investigated in other taxa, including reptiles and, more specifically, nonmarine chelonians. in these species, nest-si ... | 2010 | 20308081 |
| diagnosis of skeletal injuries in chelonians using computed tomography. | computed tomography (ct) was used to diagnose the cause of lameness in a radiated tortoise (geochelone radiata) and to determine the extent of shell and skeletal trauma in two snapping turtles (chelydra serpentina). the radiated tortoise's lameness was ultimately attributed to luxation of the right-shoulder joint that was not detected during plain film radiography. axial and appendicular fractures were identified in one of the snapping turtles that were not detected during plain film radiography ... | 2004 | 15305520 |
| case report of systemic coccidiosis in a radiated tortoise (geochelone radiata). | more than 30 species of coccidian parasites have been described in chelonidae (tortoises and turtles). eimeria spp. are apparently the most common coccidia in chelonians. findings of caryospora cheloniae, isospora sp., and mantonella sp. have also been published, but reports about systemic coccidiosis are rare. we describe a case of a coccidiosis diagnosed cytologically in a radiated tortoise (geochelone radiata) which was captive-bred in germany. infection was systemic and involved the lymphoid ... | 2008 | 17994300 |
| intranuclear coccidiosis in tortoises: nine cases. | chelonian intranuclear coccidiosis has been reported once, in two radiated tortoises (geochelone radiata), and is apparently rare. we describe intranuclear coccidiosis diagnosed histologically in two radiated tortoises, three travancore tortoises (indotestudo forstenii), two leopard tortoises (geochelone pardalis), one bowsprit tortoise (chersina angulata), and one impressed tortoise (manouria impressa). infection was systemic and involved alimentary, urogenital, respiratory, lymphoid, endocrine ... | 2006 | 16672578 |
| a molecular phylogeny of four endangered madagascar tortoises based on mtdna sequences. | four of the five tortoise species in madagascar, pyxis arachnoides, p. planicauda, geochelone radiata, and g. yniphora, are endemic and on the verge of extinction. their phylogenetic relationships remain controversial and unresolved. here we address the phylogeny of this group using dna sequences for the 12s and 16s rdna and cyt b genes in mitochondrial dna. as outgroups we used two species of geochelone, pardalis (mainland africa) and nigra (galápagos), as well as a more distant north american ... | 1999 | 10222157 |
| detection of intranuclear coccidiosis in tortoises in europe and china. | intranuclear coccidiosis of tortoises (tinc) has been described in association with systemic disease in various species of tortoises. tinc has been detected in numerous tortoises from the united states, but there are only a few reports from tropical tortoises in germany and no reports from asia. using a real-time polymerase chain reaction assay, samples from 1,011 tortoises were screened for the presence of tinc. samples originated from animals kept in captivity in europe and in china. coccidia ... | 2017 | 28749291 |
| phylogenetic position of nyctotherus teleacus isolated from a tortoise (astrochelys radiata) and its electron microscopic features. | a commensal ciliate was isolated from the stool of a tortoise (astrochelys radiata). the ciliate was classified as nyctotherus teleacus, according to its basic morphological features. electron microscopic observations using cultured n. teleacus (nictot1 strain) revealed many spherical hydrogenosomes and methanogen-suspected bacteria, together with a characteristic triangular macronucleus containing many spherical chromosomes in the cytoplasm of nictot1. the results of phylogenetic analysis showe ... | 2020 | 32336700 |
| characterization of seasonal reproductive and stress steroid hormones in wild radiated tortoises, astrochelys radiata. | the critically endangered radiated tortoise (astrochelys radiata) is endemic to the southern coastlines of madagascar. once common, wild populations of this tortoise have undergone dramatic declines in recent years. although there have been studies documenting reproductive activities, reproductive physiological parameters are unknown yet may be crucial in the recovery of the species. over four research seasons in remote field locations native to a. radiata, we surveyed for, radio-tracked, and sa ... | 2017 | 28888695 |
| undifferentiated sarcoma resolved by forelimb amputation and prosthesis in a radiated tortoise (geochelone radiata). | an adult female, radiated tortoise (geochelone radiata) presented with a grossly swollen left forelimb that restricted mobility and prevented limb withdrawal. clinical pathology revealed leukopenia (1.9 x 10(9)/l) and hyperproteinemia (69 g/l) that on protein electrophoresis was attributed to increased acute-phase proteins in the alpha fraction (26.4 g/l). biopsy revealed a poorly differentiated soft tissue sarcoma. surgical amputation at the proximal humerus was curative. to encourage postopera ... | 2005 | 17315468 |
| biochemical and hematologic values for 18 clinically healthy radiated tortoises (geochelone radiata) on st catherines island, georgia. | the radiated tortoise (geochelone radiata) is a critically endangered species in its native land, the southern portion of the island of madagascar. captive breeding programs have generated data on the breeding behavior and ecology of g radiata; however, hematologic and biochemical data also are critically important in managing populations. | 2006 | 16967417 |