SURGICAL ANATOMY OF CELIOTOMY APPROACHES TO THE STOMACH IN THE COMMON SNAPPING TURTLE ().

Entanglement in or ingestion of fishing gear is a common cause of morbidity and mortality in chelonians. Commercial and recreational fishing activities exert bycatch pressures sufficient to cause population declines in the common snapping turtle () and the alligator snapping turtle ( spp.).

The crouching of the shrew: Mechanical consequences of limb posture in small mammals.

An important trend in the early evolution of mammals was the shift from a sprawling stance, whereby the legs are held in a more abducted position, to a parasagittal one, in which the legs extend more downward. After that transition, many mammals shifted from a crouching stance to a more upright one. It is hypothesized that one consequence of these transitions was a decrease in the total mechanical power required for locomotion, because side-to-side accelerations of the body have become smaller, and thus less costly with changes in limb orientation.

Chemical Prey Luring in Jackson's Chameleons.

Lizards in the family Chamaeleonidae have been described as wiping a viscous substance from a pouch (the temporal pouch) at the angle of the jaw on branches and then capturing flies that land near the area where the wiping occurs. We confirmed the presence of this pouch in Jackson's chameleons. Histological work suggested that the material contained within is a result of decomposition of food and sloughed skin that has been trapped in the pouch rather than a glandular secretion.

Effects of Functional Electrical Stimulation on Denervated Laryngeal Muscle in a Large Animal Model.

Bilateral vocal fold paralysis (BVCP) is a life-threatening condition that follows injury to the Recurrent Laryngeal nerve (RLn) and denervation of the intrinsic laryngeal musculature. Functional electrical stimulation (FES) enables restoration and control of a wide variety of motor functions impaired by lower motor neuron lesions. Here we evaluate the effects of FES on the sole arytenoid abductor, the posterior cricoarytenoid (PCA) muscle in a large animal model of RLn injury.

Frequency dependence of power and its implications for contractile function of muscle fibers from the digital flexors of horses.

The digital flexors of horses must produce high force to support the body weight during running, and a need for these muscles to generate power is likely limited during locomotion over level ground. Measurements of power output from horse muscle fibers close to physiological temperatures, and when cyclic strain is imposed, will help to better understand the in vivo performance of the muscles as power absorbers and generators. Skinned fibers from the deep (DDF) and superficial (SDF) digital flexors, and the soleus (SOL) underwent sinusoidal oscillations in length over a range of frequencies (0.

Echolocation call production during aerial and terrestrial locomotion by New Zealand's enigmatic lesser short-tailed bat, Mystacina tuberculata.

Linkage of echolocation call production with contraction of flight muscles has been suggested to reduce the energetic cost of flight with echolocation, such that the overall cost is approximately equal to that of flight alone. However, the pattern of call production with limb movement in terrestrially agile bats has never been investigated. We used synchronised high-speed video and audio recordings to determine patterns of association between echolocation call production and limb motion by Mystacina tuberculata Gray 1843 as individuals walked and flew, respectively.

Role of the hypoglossal nerve in equine nasopharyngeal stability.

The equine upper airway is highly adapted to provide the extremely high oxygen demand associated with strenuous aerobic exercise in this species. The tongue musculature, innervated by the hypoglossal nerve, plays an important role in airway stability in humans who also have a highly adapted upper airway to allow speech. The role of the hypoglossal nerve in stabilizing the equine upper airway has not been established.

In vitro model for testing novel implants for equine laryngoplasty.

Objective: To develop an in vitro laryngeal model to mimic airflow and pressures experienced by horses at maximal exercise with which to test laryngoplasty techniques.

Study Design: Randomized complete block.

Sample Population: Cadaveric equine larynges (n=10).

Postnatal bone elongation of the manus versus pes: analysis of the chondrocytic differentiation cascade in Mus musculus and Eptesicus fuscus.

Bones elongate postnatally by endochondral ossification as cells of the cartilaginous growth plate undergo a differentiation cascade of proliferation, cellular hypertrophy and matrix synthesis. Interspecific comparisons of homologous bones elongating at different rates has been a useful approach for studying the dynamics of this process. The purpose of this study was to measure quantitative stereological parameters of growth plates of the third digit of the manus and pes of the laboratory mouse, and make comparisons to chondrocytic performance parameters in the homologous bones of the big brown bat, Eptesicus fuscus, where extremely rapid postnatal elongation of bones of the manus is associated with skeletal modifications for powered flight.

Forelimb versus hindlimb skeletal development in the big brown bat, Eptesicus fuscus: functional divergence is reflected in chondrocytic performance in Autopodial growth plates.

The morphology of the chiropteran forelimb demonstrates musculoskeletal specializations for powered flight essentially unique among mammals, including extreme elongation of the distal skeletal elements. Recent studies have focused primarily on the relative timing and levels of gene expression during early stages of endochondral ossification in the chiropteran embryo for clues to the molecular basis of the evolutionary origins of flight in these species. The goal of the current study was to examine how elongation of skeletal elements of the forelimb autopod is achieved through a combination of cellular proliferation, cellular enlargement and matrix synthesis during a period of rapid postnatal growth in Eptesicus fuscus.

Growth and development of two species of bats in a shared maternity roost.

Skeletogenesis was studied in two species of bats, Myotis austroriparius (southeastern brown bat) and Tadarida brasiliensis (Brazilian free-tailed bat), occupying a maternity roost in central Florida. These bats often use distinct maternity roost environments, so this provided an opportunity to examine differential patterns of long bone growth while fetuses and newborn developed under similar environmental conditions. Some differences in the timing of onset of osteogenesis were revealed in the bats, indicating that some elements of the hindlimb develop relatively more rapidly in T.

Horse soleus muscle: postural sensor or vestigial structure?

The soleus muscle of horses is rather diminutive with respect to the overall size of adjacent synergist muscles in the hind limb of the horse. Whether or not such a muscle might be vestigial or may be providing some essential function has not been determined. We have studied the horse's soleus muscle using histochemical (ATPase), immunocytochemical (myosin isoform identification), and SDS-PAGE analysis to demonstrate that it is largely composed of 100% type I, presumed slow-twitch fibers.

Terrestrial locomotion of the New Zealand short-tailed bat Mystacina tuberculata and the common vampire bat Desmodus rotundus.

Bats (Chiroptera) are generally awkward crawlers, but the common vampire bat (Desmodus rotundus) and the New Zealand short-tailed bat (Mystacina tuberculata) have independently evolved the ability to manoeuvre well on the ground. In this study we describe the kinematics of locomotion in both species, and the kinetics of locomotion in M. tuberculata.

Muscular design in the equine interosseus muscle.

We studied the forelimb interosseus muscle in horses, Equus caballus, to determine the muscular properties inherent in its function. Some authors have speculated that the equine interosseus contains muscle fibers at birth only to undergo loss of these fibers through postnatal ontogeny. We describe the muscle fibers in eight interosseus specimens from adult horses.

Testing the hindlimb-strength hypothesis: non-aerial locomotion by Chiroptera is not constrained by the dimensions of the femur or tibia.

In the evolution of flight bats appear to have suffered a trade-off; they have become poor crawlers relative to terrestrial mammals. Capable walking does occur in a few disparate taxa, including the vampire bats, but the vast majority of bats are able only to shuffle awkwardly along the ground, and the morphological bases of differences in crawling ability are not currently understood. One widely cited hypothesis suggests that the femora of most bats are too weak to withstand the compressive forces that occur during terrestrial locomotion, and that the vampire bats can walk because they possess more robust hindlimb skeletons.

Biomechanics: independent evolution of running in vampire bats.

Most tetrapods have retained terrestrial locomotion since it evolved in the Palaeozoic era, but bats have become so specialized for flight that they have almost lost the ability to manoeuvre on land at all. Vampire bats, which sneak up on their prey along the ground, are an important exception. Here we show that common vampire bats can also run by using a unique bounding gait, in which the forelimbs instead of the hindlimbs are recruited for force production as the wings are much more powerful than the legs.