scholarly journals Ontogenetic and inter-elemental osteohistological variability in the leopard tortoise Stigmochelys pardalis

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8030 ◽  
Author(s):  
Alexander Edward Botha ◽  
Jennifer Botha

Testudines are a group of reptiles characterized by the presence of a shell covered by keratinous shields. Stigmochelys pardalis is the most widely distributed terrestrial testudine in southern Africa. Although relatively common with some life history traits being well known, the growth of this species has yet to be studied in any detail. The bone microanatomy of this clade differs from that found in other amniotes, where terrestrial species tend to display characteristics normally seen in aquatic species and vice versa. A detailed histological analysis of the limb bones of S. pardalis reveals extensive variation through ontogeny. Cortical bone becomes increasingly thicker through ontogeny and is finally resorbed in the late sub-adult stage, resulting in a thin cortex and a large infilled medullary cavity. The predominant bone tissues are parallel-fibred and lamellar-zonal for the forelimbs and hind limbs respectively. The oldest individual displayed an External Fundamental System indicating that the growth rate had decreased substantially by this stage. Variability is prevalent between the forelimb and hind limb as well as between early and late sub-adults Forelimb elements exhibit characteristics such as faster growing parallel-fibered bone tissue, slightly higher vascularization and a predominance of annuli over Lines of Arrested Growth (LAG) compared to the hind limb which exhibits poorly vascularized, slower growing lamellar-zonal bone interrupted by LAGs. These differences indicate that the forelimb grew more rapidly than the hind limb, possibly due to the method of locomotion seen in terrestrial species. The extensive bone resorption that occurs from the early sub-adult stage destroys much of the primary cortex and results in a significantly different ratio of inner and outer bone diameter (p = 3.59 × 10­−5; df = 28.04) as well as compactness (p = 2.91 × 10­−5; df = 31.27) between early and late sub-adults. The extensive bone resorption seen also destroys the ecological signal and infers an aquatic lifestyle for this species despite it being clearly terrestrial. This supports the results of other studies that have found that using bone microanatomy to determine lifestyle in testudines does not produce accurate results.

2018 ◽  
Vol 46 (1) ◽  
Author(s):  
Catarina Borges Cardoso ◽  
Sheila Canevese Rahal ◽  
Maria Jaqueline Mamprim ◽  
Hugo Salvador Oliveira ◽  
Alessandra Melchert ◽  
...  

Background: The avascular necrosis of the femoral head is a development disease caused by ischemic necrosis, which is mainly observed in young dogs. The etiology of the disease remains controversial. The diagnosis requires imaging exams such as MRI and radiographs. Thus, the aim of the current study was to retrospectively assess a population of dogs with avascular necrosis of the femoral head in order to feature the disease, as well as to analyze the radiographic appearance of the lesion at the moment of patient consultation.Materials, Methods & Results: The signalment factors of dogs (breed, gender, age and body mass), the affected hind limb, the radiographic appearance of the lesion, the clinical signs at the moment of patient consultation, the time of occurrence and the type of treatment were evaluated. The disease was radiographically classified according to the previously described items. Forty-three cases of avascular necrosis of the femoral head were identified, 97.67% presented lameness and pain during palpation of the hip joint; and 54.34%, were 1 week to 4 months old. Females represented 58.13% of the sample, and 65.11% of them weighed from 2.6 to 4.9 kg. Based on the radiographic classification, 4.34% were Grade 1; 32.60%, Grade 2; 8.69%, Grade 3; 19.56%, Grade 4; and 34.78%, Grade 5. The femoral head and neck ostectomy was performed in 42 hind limbs (91.30%); 42.85% of the dogs reached total functional recovery and 26.19% required physiotherapy and rehabilitation.Discussion: The present sample was composed of 25 dogs, which were 6-to-11-month old at the moment of patient consultation, but 17 dogs were 12-to-36-month old at this time; only one dog was older than 36 months. It may be associated with the non-recognition of clinical signs by the owners, rather than with the late-onset form of the disease. With respect to the breed, pinscher, Yorkshire, poodle, Lhasa apso, pug were most frequently observed. However, 7 dogs were crossbreed. Such group differed from that of a review involving 188 cases encompassing West Highland white terrier, Cairn terrier and poodle as the most commonly affected breeds. No sex predilection was found in a study comprising 188 cases, but in another study comprising 14 dogs, female predilection was observed. Likewise, the females represented 58.13% of cases in the present study; and 41.86% of the participants were male. The mean body mass of the dogs in the current study was 4.33 kg, which matches the small breed dogs, which are most affected by the disease. Clinical signs of non-weightbearing lameness or an intermittent subtle lameness are common in the avascular necrosis of the femoral head. Lameness of the affected hind limb was observed in 69.76% of the cases in the present study, but 2.32% showed no lameness. Occasionally, the avascular necrosis of the femoral head is bilaterally found in 12% to 16.5% of the cases. Only 3 out of the 43 cases assessed in the present study were bilateral. Since the lesions were more frequent in Grades 2 and 5, there is less chance of success through the conservative treatment. Thus, the femoral head and neck ostectomy was the surgical procedure performed in 42 hind limbs. The procedure is used to provide pain relief and to reduce the signs of lameness. In conclusion, the population assessed in the present study was composed of small size dogs, mean body mass 4.33 kg, no sex predilection, mostly presenting unilateral lesions and higher Grade 2 and Grade 5 radiographic lesion frequency.Keywords: radiographic, joint, canine, hip.


2019 ◽  
Vol 66 (4) ◽  
pp. 417-424
Author(s):  
Gregorio Moreno-Rueda ◽  
Abelardo Requena-Blanco ◽  
Francisco J Zamora-Camacho ◽  
Mar Comas ◽  
Guillem Pascual

Abstract Predation is one of the main selective forces in nature, frequently selecting potential prey for developing escape strategies. Escape ability is typically influenced by several morphological parameters, such as morphology of the locomotor appendices, muscular capacity, body mass, or fluctuating asymmetry, and may differ between sexes and age classes. In this study, we tested the relationship among these variables and jumping performance in 712 Iberian green frogs Pelophylax perezi from an urban population. The results suggest that the main determinant of jumping capacity was body size (explaining 48% of variance). Larger frogs jumped farther, but jumping performance reached an asymptote for the largest frogs. Once controlled by structural body size, the heaviest frogs jumped shorter distances, suggesting a trade-off between fat storage and jumping performance. Relative hind limb length also determined a small but significant percentage of variance (2.4%) in jumping performance—that is, the longer the hind limbs, the greater the jumping capacity. Juveniles had relatively shorter and less muscular hind limbs than adults (for a given body size), and their jumping performance was poorer. In our study population, the hind limbs of the frogs were very symmetrical, and we found no effect of fluctuating asymmetry on jumping performance. Therefore, our study provides evidence that jumping performance in frogs is not only affected by body size, but also by body mass and hind limb length, and differ between age classes.


Development ◽  
1982 ◽  
Vol 72 (1) ◽  
pp. 269-286
Author(s):  
N. G. Laing

Counts were made of the number of motoneurons innervating the hind limbs of 10-day normal and paralysed chick embryos whose right hind limb buds had been subjected to varying degrees of amputation prior to innervation. The number of motoneurons on the intact sides of the paralysed embryos was found to be similar to the number present in normal embryos prior to the major period of motoneuron death. Since it has previously been shown that paralysis does not increase the number of motoneurons generated, this means that normal motoneuron death was largely prevented in the paralysed embryos. There were differences in the distributions of motoneurons in the rostrocaudal axis of the spinal cord between normal and paralysed embryos. Therefore, cell death does not eliminate a uniform fraction of motoneurons throughout the rostrocaudal extent of the chick embryo lumbar lateral motor column. It is also argued that there are differences in the relative contribution of the various lumbosacral levels to different parts of the limb, e.g. the shank, before and after the period of cell death. In both normal and paralysed embryos there was a linear relationship between the volume of limb muscle which developed after amputation and the number of motoneurons surviving in the spinal cord. There was no evidence of a ‘compression’ of motoneurons into the remaining muscle either after amputation alone or after amputation combined with paralysis. Motoneurons are therefore rigidly specified for certain parts of the limb. The relationship between motoneuron number and muscle volume on the amputated side differed from that of the intact side. For a similar increase in muscle volume there was a smaller increase in motoneuron number on the intact sides. This suggested a parallel to the paradoxically small increase in motoneuron number that occurs on the addition of a supernumerary limb.


1980 ◽  
Vol 17 (3) ◽  
pp. 305-315 ◽  
Author(s):  
R. Bradley ◽  
W.V.S. Wueratne

A 5-year-old Friesian stud bull developed a progressive locomotor disorder on return to stud after a period of rest. He had defects in conformation exacerbated by poor condition. The hind limbs were excessively straight. When he stood or moved, the Achilles tendons and their associated muscles were rigid. The disorder clinically resembled spastic paresis of calves. Necropsy showed a degenerative arthropathy in all hind limb joints below the hip. Lesions were also in tendons and skeletal muscles. The M. flexor digitorum superficialis had severe type II cell atrophy with many ring. lobulated and moth-eaten type I cells.


1962 ◽  
Vol 39 (2) ◽  
pp. 239-242
Author(s):  
J. TEN CATE

1. The locomotory movements of the hind limb of the spinal cat have been studied with the animal supported on a wheeled carriage so that the soles of the hind feet rest upon the ground. 2. Locomotory movements of the hind limbs do not occur spontaneously, but only in response to stimulation of proprioceptors and exteroceptors. Such stimulation is provided by locomotory movements of the fore limbs or by forward movement of the carriage. After cessation of these stimulatory movements the locomotory movements of the hind limbs are not maintained. 3. In these respects the spinal cat differs from the spinal pigeon, and it is suggested that the greater autonomy of the lumbosacral cord in the latter is related to its bipedal gait.


Author(s):  
Katharine M. Simpson ◽  
Robert N. Streeter

Abstract OBJECTIVE To describe clinical findings, treatments, and outcomes for cattle with complete traumatic exungulation. ANIMALS 10 bovines. PROCEDURES Record databases of 2 teaching hospitals were searched to identify cattle treated for traumatic exungulation between January 1993 and December 2018. Information about signalment, clinical signs and findings, treatment, and outcome was extracted from the records or obtained by telephone communication with the owner. RESULTS Records for 5 bulls, 4 heifers, and 1 cow with a median age of 2 years (range, 1 day to 10 years) and weight of 379.1 kg (range, 30 to 909.1 kg) were reviewed. Duration of clinical signs ranged from ≤ 24 hours to 3.5 days. Five of 7 animals had a lameness score > 3/5. Complete exungulation occurred in 6 medial digits (3 hind limbs and 3 forelimbs) and 5 lateral digits (1 hind limb and 4 forelimbs); 1 calf had complete exungulation of both digits of a forelimb. Treatments included bandaging (n = 9), antimicrobials (9), anti-inflammatories (8), hoof block application to the adjacent digit (7), regional anesthesia (6), cast application (4), curettage of the third phalanx (3), regional antimicrobial perfusion (1), and local application of antimicrobial-impregnated beads (1). All 7 cattle with long-term (≥ 9 months) information available returned to their intended function; 6 had no residual lameness, and 3 required regular corrective trimming of the affected digit. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested the prognosis for long-term survival and return to intended function is fair to good for cattle with complete exungulation.


Author(s):  
Libaihe Jing ◽  
Peng He ◽  
Dongfang Ding ◽  
Can Qu ◽  
Baoping Shao ◽  
...  

2019 ◽  
Vol 286 (1908) ◽  
pp. 20190906 ◽  
Author(s):  
Christine W. Miller ◽  
Paul N. Joseph ◽  
Rebecca M. Kilner ◽  
Zachary Emberts

Sexually selected weapons are assumed to trade off with traits related to ejaculates, such as testes. However, remarkably little is known about what governs resource allocation and why trade-offs are found in some cases and not others. Often-used models depict competitive allocation occurring within the functional grouping of traits (e.g. reproduction); however, other factors including tissue expense and developmental timing may influence allocation. Experimental comparisons of investment across the sexes have the potential to illuminate allocation rules, because the sexes do not always use traits for the same functions. Here, we capitalize upon a species where females have weapons–testes homologues. We report that a documented trade-off in investment between hind-limb weapons and testes in leaf-footed cactus bugs, Narnia femorata , is even more pronounced in female hind limbs and ovaries. Female hind limbs in this species do not share the clear reproductive function of male hind limbs; therefore, this trade-off spans trait functional groups. Such patterns of investment suggest that future studies of reproductive trade-offs should consider factors such as tissue expense and developmental timing.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
P Parsi-Pour ◽  
B M Kilbourne

Synopsis Locomotor habits in mammals are strongly tied to limb bones’ lengths, diameters, and proportions. By comparison, fewer studies have examined how limb bone cross-sectional traits relate to locomotor habit. Here, we tested whether climbing, digging, and swimming locomotor habits reflect biomechanically meaningful differences in three cross-sectional traits rendered dimensionless— cross-sectional area (CSA), second moments of area (SMA), and section modulus (MOD)—using femora, tibiae, and fibulae of 28 species of mustelid. CSA and SMA represent resistance to axial compression and bending, respectively, whereas MOD represents structural strength. Given the need to counteract buoyancy in aquatic environments and soil’s high density, we predicted that natatorial and fossorial mustelids have higher values of cross-sectional traits. For all three traits, we found that natatorial mustelids have the highest values, followed by fossorial mustelids, with both of these groups significantly differing from scansorial mustelids. However, phylogenetic relatedness strongly influences diversity in cross-sectional morphology, as locomotor habit strongly correlates with phylogeny. Testing whether hind limb bone cross-sectional traits have evolved adaptively, we fit Ornstein–Uhlenbeck (OU) and Brownian motion (BM) models of trait diversification to cross-sectional traits. The cross-sectional traits of the femur, tibia, and fibula appear to have, respectively, diversified under a multi-rate BM model, a single rate BM model, and a multi-optima OU model. In light of recent studies on mustelid body size and elongation, our findings suggest that the mustelid body plan—and perhaps that of other mammals—is likely the sum of a suite of traits evolving under different models of trait diversification.


2020 ◽  
Vol 27 (4) ◽  
pp. 627-647 ◽  
Author(s):  
Christine M. Janis ◽  
James G. Napoli ◽  
Coral Billingham ◽  
Alberto Martín-Serra

Abstract Sthenurine kangaroos, extinct “giant kangaroos” known predominantly from the Plio-Pleistocene, have been proposed to have used bipedal striding as a mode of locomotion, based on the morphology of their hind limbs. However, sthenurine forelimb morphology has not been considered in this context, and has important bearing as to whether these kangaroos employed quadrupedal or pentapedal locomotion as a slow gait, as in extant kangaroos. Study of the correlation of morphology of the proximal humerus in a broad range of therian mammals shows that humeral morphology is indicative of the degree of weight-bearing on the forelimbs during locomotion, with terrestrial species being distinctly different from arboreal ones. Extant kangaroos have a proximal humeral morphology similar to extant scansorial (semi-arboreal) mammals, but sthenurine humeri resemble those of suspensory arboreal taxa, which rarely bear weight on their forelimbs, supporting the hypothesis that they used bipedal striding rather than quadrupedal locomotion at slow gaits. The humeral morphology of the enigmatic extinct “giant wallaby,” Protemnodon, may be indicative of a greater extent of quadrupedal locomotion than in extant kangaroos.


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