scholarly journals Kinematics of feeding in the lizard Agama stellio

1996 ◽  
Vol 199 (8) ◽  
pp. 1727-1742 ◽  
Author(s):  
A Herrel ◽  
J Cleuren ◽  
F Vree
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Prey Type ◽  
The Body ◽  
Kinematic Data ◽  
Video Recordings ◽  
Lower Jaw ◽  
Feeding Cycle ◽  
Hyolingual Apparatus ◽  
Opening Phase

The kinematics of prey capture, intraoral transport and swallowing in lizards of the species Agama stellio (Agamidae) were investigated using cineradiography (50 frames s-1) and high-speed video recordings (500 frames s-1). Small metal markers were inserted into different parts of the upper and lower jaw and the tongue. Video and cineradiographic images were digitized, and displacements of the body, head, upper and lower jaw and the tongue were quantified. Twenty additional variables depicting displacements and timing of events were calculated. A factor analysis performed on the kinematic data separates prey capture and swallowing cycles from intraoral transport bites. However, the intraoral transport stage cannot be separated into chewing (reduction) and transport bites. The effect of prey type and size on the feeding kinematics of intraoral transport and swallowing cycles was investigated. During the intraoral transport stage, distinct aspects (e.g. durations, maximal excursions) of the gape and tongue cycle are modulated in response to both the size and type of the prey item. The results for A. stellio generally agree with a previous model, although it is the entire slow opening phase rather than solely the duration of the second part of this phase that is affected by the size of the prey. The intraoral transport cycles in A. stellio show the two synapomorphic characteristics of tetrapods (tongue-based terrestrial intraoral prey transport and the existence of a long preparatory period of prey compression). However, not all five characters of the feeding cycle previously proposed for amniotes are present in A. stellio. One major difference is that in A. stellio the recovery of the hyolingual apparatus does not take place during the slow opening phase but during the slow closing/powerstroke phase.

Water skating in the larvae of dixella aestivalis (Diptera) and hydrobius fuscipes (Coleoptera)

1999 ◽  
Vol 202 (7) ◽  
pp. 845-853
Author(s):  
J. Brackenbury
Keyword(s):  
High Speed ◽  
The Body ◽  
Water Interface ◽  
Body Movements ◽  
Chironomid Larvae ◽  
High Speed Video ◽  
Adhesive Organ ◽  
Video Recordings ◽  
Air Water Interface

The kinematics of locomotion was investigated in the aquatic larvae of Dixella aestivalis and Hydrobius fuscipes with the aid of high-speed video recordings. Both insects are able to skate on the surface of the water using the dorso-apical tracheal gill as an adhesive organ or ‘foot’. Progress relies on the variable adhesion of the foot between ‘slide’ and ‘hold’ periods of the locomotory cycle. The flexural body movements underlying skating in D. aestivalis can be derived directly from the figure-of-eight swimming mechanism used in underwater swimming. The latter is shown to be similar to figure-of-eight swimming in chironomid larvae. This study shows how the deployment of a ‘foot’ enables simple side-to-side flexural movements of the body to be converted into effective locomotion at the air-water interface.

scholarly journals More than a safety line: jump-stabilizing silk of salticids

2013 ◽  
Vol 10 (87) ◽  
pp. 20130572 ◽  
Author(s):  
Yung-Kang Chen ◽  
Chen-Pan Liao ◽  
Feng-Yueh Tsai ◽  
Kai-Jung Chi
Keyword(s):  
Energy Dissipation ◽  
Dynamic Stability ◽  
Material Properties ◽  
High Speed ◽  
Prey Capture ◽  
Flapping Wings ◽  
Aerodynamic Forces ◽  
Physiological Control ◽  
Dragline Silk ◽  
Kinematic Data

Salticids are diurnal hunters known for acute vision, remarkable predatory strategies and jumping ability. Like other jumpers, they strive for stability and smooth landings. Instead of using inertia from swinging appendages or aerodynamic forces by flapping wings as in other organisms, we show that salticids use a different mechanism for in-air stability by using dragline silk, which was previously believed to function solely as a safety line. Analyses from high-speed images of jumps by the salticid Hasarius adansoni demonstrate that despite being subject to rearward pitch at take-off, spiders with dragline silk can change body orientation in the air. Instantaneous drag and silk forces calculated from kinematic data further suggest a comparable contribution to deceleration and energy dissipation, and reveal that adjustments by the spider to the silk force can reverse its body pitch for a predictable and optimal landing. Without silk, upright-landing spiders would slip or even tumble, deferring completion of landing. Thus, for salticids, dragline silk is critical for dynamic stability and prey-capture efficiency. The dynamic functioning of dragline silk revealed in this study can advance the understanding of silk's physiological control over material properties and its significance to spider ecology and evolution, and also provide inspiration for future manoeuvrable robot designs.

Quantitative analysis of prey-capture kinematics in Anolis equestris (Reptilia: Iguanidae)

1990 ◽  
Vol 68 (10) ◽  
pp. 2192-2198 ◽  
Author(s):  
Vincent L. Bels
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Anterior Part ◽  
The Body ◽  
Original Position ◽  
Forward Movement ◽  
Live Prey ◽  
Capture Process ◽  
Locomotor System ◽  
Cyclic Movement

High-speed cinematography was employed to study the mechanics of prey capture in Anolis equestris. Capture of live prey (adult locusts) consists of a cyclic movement of the upper and lower jaws combined with tongue protraction. Kinematic profiles are presented for the jaws, tongue, and forelimbs. The tongue is projected during the "slow open" stage and most of the "fast open" stage. The tongue protrudes beyond the mandibular symphysis during the slow open stage, and rotates simultaneously around a transverse anteromedian axis. The prey is thus contacted by the dorsal sticky surface of the tongue, and then pulled backward into the oral cavity by a combination of a forward movement of the jaws and retraction of the tongue. Gape angle, defined as the angle between the upper and lower jaws, continues to increase during the initial stages of tongue retraction. During the capture process, the anterior part of the body lunges forward, followed by a return to its original position; this displacement is mediated by the forelimbs, which usually remain well anchored to the floor. The cyclic food-capture movements of the jaws and tongue–hyoid system in A. equestris (Iguanidae) and Chameleo dilepis (Chamaeleontidae) are compared. I argue that one of the primary selection forces in the evolution of the different mechanisms of prey prehension in these two lizard groups was enhancement of the locomotor system and, consequently, foraging ability.

Modulation of prey-capture behavior in the plethodontid salamander Ensatina eschscholtzii

1997 ◽  
Vol 200 (14) ◽  
pp. 1951-1964 ◽  
Author(s):  
S Deban
Keyword(s):  
High Speed ◽  
Sensory Feedback ◽  
Prey Capture ◽  
Prey Size ◽  
Sensory Information ◽  
Prey Type ◽  
Jaw Movements ◽  
Plethodontid Salamander ◽  
Ensatina Eschscholtzii ◽  
Prey Capture Behavior

The hypothesis that salamander prey-capture behavior is highly stereotyped was tested in the plethodontid salamander Ensatina eschscholtzii using high-speed videography and kinematic analysis of feedings on two types of prey (waxworms and termites). The results show that E. eschscholtzii is capable of modulating the timing and magnitude of tongue and jaw movements in response to prey type. Feedings on waxworms, the larger prey, were characterized by shorter durations and higher velocities of tongue and jaw movements compared with feedings on termites, particularly in the latter portion of the feeding sequence (i.e. after prey contact). To test the hypothesis that sensory feedback through the tongue pad plays a role in modulating feeding movements in response to prey type, the ramus lingualis of the glossopharyngeal nerve (cranial nerve IX), which is known to carry sensory information from the tongue pad in salamanders, was transected bilaterally. This experimental deafferentation of the tongue pad had no effect on the degree or direction of differences in feeding kinematics across prey type. These results refute the glossopharyngeal feedback hypothesis, but are consistent with the hypothesis that E. eschscholtzii responds more vigorously to larger prey by assessing prey size visually.

The Mechanism of Tongue Projection in Chameleons: I. Electromyographic Tests of Functional Hypotheses

1992 ◽  
Vol 168 (1) ◽  
pp. 1-21 ◽  
Author(s):  
PETER C. WAINWRIGHT ◽  
ALBERT F. BENNETT
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Activity Patterns ◽  
Motor Pattern ◽  
Companion Paper ◽  
Posterior Portion ◽  
Video Recordings ◽  
Single Burst ◽  
Intense Activity ◽  
Test Current

In this paper we document the activity of key muscles of the tongue, hyobranchial apparatus and head during prey capture in the lizard Chamaeleo jacksonii Boulenger and use these data to test current hypotheses of chameleon tongue function. Electromyographic recordings were made during 27 feedings from nine individuals and synchronized with high-speed video recordings (200 fields s−1), permitting an assessment of the activity of muscles relative to the onset of tongue projection, contact between tongue and prey, and tongue retraction. Four major results were obtained. (1) The hyoglossi muscles exhibit a single burst of activity that begins between 10 ms before and 20 ms after the onset of tongue projection and continues throughout the period of tongue retraction. (2) The accelerator muscle exhibits a biphasic activity pattern, with the first burst lasting about 185 ms and ending an average of 10.6 ms prior to the onset of projection. (3) The accelerator muscle shows regional variation in morphology that corresponds with variation in motor pattern. The anterior region of the muscle, unlike the posterior portion, exhibits only a single burst of activity that begins 2.5 ms after the onset of tongue projection and is thus not involved in launching the tongue. (4) The geniohyoidei, sternohyoidei, sternothyroidei, depressor mandibulae, adductor mandibulae and pterygoideus all exhibit activity patterns consistent with previously reported kinematic patterns and their proposed roles. The major implications of these results for models of the chameleon feeding mechanism are (1) that the hyoglossi do not act to hold the tongue on the entoglossal process during a loading period prior to tongue projection, and (2) that the presence of 185 ms of intense activity in the accelerator muscle prior to tongue projection suggests the presence of a preloading mechanism, the nature of which is the subject of the companion paper.

Use of sonomicrometry demonstrates the link between prey capture kinematics and suction pressure in largemouth bass

2002 ◽  
Vol 205 (22) ◽  
pp. 3445-3457 ◽  
Author(s):  
Christopher P. J. Sanford ◽  
Peter C. Wainwright
Keyword(s):  
Largemouth Bass ◽  
High Speed ◽  
Prey Capture ◽  
Buccal Cavity ◽  
Micropterus Salmoides ◽  
Sampling Rate ◽  
Great Promise ◽  
Suction Pressure ◽  
Video Recordings ◽  
Explosive Expansion

SUMMARYSuction feeding in fishes is the result of a highly coordinated explosive expansion of the buccal cavity that results in a rapid drop in pressure. Prey are drawn into the mouth by a flow of water that is generated by this expansion. At a gross level it is clear that the expansion of the buccal cavity is responsible for the drop in pressure. However, attempts using high-speed video recordings to demonstrate a tight link between prey capture kinematics and suction pressure have met with limited success. In a study with largemouth bass Micropterus salmoides, we adopted a new technique for studying kinematics, sonomicrometry, to transduce the movement of skeletal elements of the head during feeding, and synchronized pressure recordings at a sampling rate of 500 Hz. From the positional relationships of six piezoelectric crystals we monitored the internal movements of the buccal cavity and mouth in both mid-sagittal and transverse planes. We found that peak subambient pressure was reached very early in the kinematic expansion of the buccal cavity, occurring at the time when the rate of percentage change in buccal volume was at its peak. Using multiple regression analyses we were consistently able to account for over 90%, and in the best model 99%, of the variation in buccal pressure among strikes using kinematic variables. Sonomicrometry shows great promise as a method for documenting movements of biological structures that are not clearly visible in the external view provided by film and video recordings.

Simple mechanisms organise orientation of escape swimming in embryos and hatchling tadpoles of Xenopus laevis

2000 ◽  
Vol 203 (12) ◽  
pp. 1869-1885 ◽  
Author(s):  
A. Roberts ◽  
N.A. Hill ◽  
R. Hicks
Keyword(s):  
Mathematical Model ◽  
Xenopus Laevis ◽  
High Speed ◽  
Three Dimensional ◽  
Longitudinal Axis ◽  
The Body ◽  
Video Recordings ◽  
Stage Of Development ◽  
Physical Features ◽  
Neutrally Buoyant

Many amphibian tadpoles hatch and swim before their inner ears and sense of spatial orientation differentiate. We describe upward and downward swimming responses in hatchling Xenopus laevis tadpoles from stages 32 to 37/38 in which the body rotates about its longitudinal axis. Tadpoles are heavier than water and, if touched while lying on the substratum, they reliably swim upwards, often in a tight spiral. This response has been observed using stroboscopic photography and high-speed video recordings. The sense of the spiral is not fixed for individual tadpoles. In ‘more horizontal swimming’ (i.e. in directions within +/−30 degrees of the horizontal), the tadpoles usually swim belly-down, but this position is not a prerequisite for subsequent upward spiral swimming. Newly hatched tadpoles spend 99 % of their time hanging tail-down from mucus secreted by a cement gland on the head. When suspended in mid-water by a mucus strand, tadpoles from stage 31 to 37/38 tend to swim spirally down when touched on the head and up when touched on the tail. The three-dimensional swimming paths of stage 33/34 tadpoles were plotted using simultaneous video images recorded from the side and from above. Tadpoles spiralled for 70 % of the swimming time, and the probability of spiralling increased to 1 as swim path angles became more vertical. Tadpoles were neutrally buoyant in Percoll/water mixtures at 1.05 g cm(−)(3), in which anaesthetised tadpoles floated belly-down and head-up at 30 degrees. In water, their centre of mass was ventral to the muscles in the yolk mass. A simple mathematical model suggests that the orientation of tadpoles during swimming is governed by the action of two torques, one of which raises the head (i.e. increases the pitch) and the other rotates (rolls) the body. Consequently, tadpoles (i) swim belly-down when the body is approximately horizontal because the body is ballasted by dense yolk, and (ii) swim spirally at more vertical orientations when the ballasting no longer stabilises orientation. Measurements in tethered tadpoles show that dorsal body flexion, which could produce a dorsal pitch torque, is present during swimming and increases with tailbeat frequency. We discuss how much of the tadpole's behaviour can be explained by our mathematical model and suggest that, at this stage of development, oriented swimming responses may depend on simple touch reflexes, the organisation of the muscles and physical features of the body, rather than on vestibular reflexes.

scholarly journals Kinematics of prey capture in a flatfish, Pleuronichthys verticalis

1995 ◽  
Vol 198 (5) ◽  
pp. 1173-1183 ◽  
Author(s):  
A Gibb
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Mouth Opening ◽  
Significant Degree ◽  
The Body ◽  
Bilateral Asymmetry ◽  
Ocular Side ◽  
Functional Features ◽  
Prey Capture Behavior ◽  
Pleuronichthys Verticalis

Hornyhead turbot, Pleuronichthys verticalis (Pleuronectiformes: Pleuronectidae), are morphologically asymmetrical teleosts with substantial bilateral asymmetry in the neurocranium, suspensorium and anterior jaws. In order to quantify the kinematics of prey capture and to test for functional bilateral asymmetries, four individuals of this species were video-taped feeding using a high-speed video system at 200 fields s-1. Frame-by-frame analysis revealed several features not commonly found in prey capture behavior of previously studied ray-finned fishes. These features include (1) extreme lateral compression of the suspensorium and opercular series prior to mouth opening, indicating the consistent presence of a preparatory phase during feeding, (2) apparent dissociation of hyoid retraction and lower jaw depression, (3) prolonged hyoid retraction throughout much of the feeding cycle, and (4) concomitant dorsal rotation of the neurocranium and closing of the jaws. P. verticalis also demonstrate a significant degree of functional bilateral asymmetry during prey capture. When approaching prey, fish flex their heads towards the ocular (anatomically the right) side of the body. During prey capture, their jaws bend out of the midline towards the blind (left) side. Comparisons of the displacement and timing for movements of homologous anatomical features on the ocular and blind sides of the head reveal that maximum gape is always larger on the blind side of the head than on the ocular side. In contrast, other kinematic variables measured are similar on both sides of the head. These results suggest that P. verticalis possess unique functional features of prey capture behavior and that morphological bilateral asymmetry of the head and jaws is associated with, and perhaps causally related to, the functional bilateral asymmetry present during feeding.

Kinematics of intraoral transport and swallowing in the herbivorous lizard uromastix acanthinurus

1999 ◽  
Vol 202 (9) ◽  
pp. 1127-1137 ◽  
Author(s):  
A. Herrel ◽  
F.D. Vree
Keyword(s):  
High Speed ◽  
Multivariate Analyses ◽  
The Body ◽  
Food Type ◽  
Published Data ◽  
Lower Jaw ◽  
Video Systems ◽  
Different Parts

The kinematics of intraoral transport and swallowing in lizards of the species Uromastix acanthinurus (Chamaeleonidae, Leiolepidinae) were investigated using cineradiography (50 frames s-1). Additional recordings were also made using high-speed (500 frames s-1) and conventional video systems (25 frames s-1). Small metal markers were inserted into different parts of the upper and lower jaw and the tongue. Cineradiographic images were digitised, and displacements of the body, head, upper and lower jaw and the tongue were quantified. Twenty additional variables depicting displacements and the timing of events were calculated. Multivariate analyses of variance indicated significant differences between feeding stages. Remarkably, only very few food-type-dependent differences were observed during intraoral transport, and no such differences could be demonstrated during swallowing. Using previously published data for the closely related insectivorous lizard Plocederma stellio, the effect of dietary specialisation in U. acanthinurus on the kinematic variables while eating locusts was examined. Species differed in a number of gape- and tongue-related variables. These differences may be related to differences in tongue structure between the species. Clearly, U. acanthinurus possesses a specialised gut and dental structure that allows them efficiently to cut pieces from whole leaves. However, a decrease in modulatory capacity seems to be a consequence of dietary specialisation in Uromastix acanthinurus.

scholarly journals Flexibility of intraoral food processing in the salamandrid newt Triturus carnifex: effects of environment and prey type

2020 ◽  
Vol 223 (21) ◽  
pp. jeb232868
Author(s):  
Daniel Schwarz ◽  
Stanislav N. Gorb ◽  
Alexander Kovalev ◽  
Nicolai Konow ◽  
Egon Heiss
Keyword(s):  
Mechanical Properties ◽  
Environmental Conditions ◽  
Food Processing ◽  
High Speed ◽  
Prey Capture ◽  
Prey Type ◽  
Functional Adaptation ◽  
Food Type ◽  
Form And Function ◽  
Terrestrial Habitats

ABSTRACTIntraoral food processing mechanisms are known for all major vertebrate groups, but the form and function of systems used to crush, grind or puncture food items can differ substantially between and within groups. Most vertebrates display flexible mechanisms of intraoral food processing with respect to different environmental conditions or food types. It has recently been shown that newts use cyclical loop-motions of the tongue to rasp prey against the palatal dentition. However, it remains unknown whether newts can adjust their food processing behavior in response to different food types or environmental conditions. Newts are interesting models for studying the functional adaptation to different conditions because of their unique and flexible lifestyle: they seasonally change between aquatic and terrestrial habitats, adapt their prey-capture mode to the respective environment, and consume diverse food types with different mechanical properties. Using X-ray high-speed recordings, anatomical investigations, behavioral analyses and mechanical property measurements, we tested the effects of the medium in which feeding occurs (water/air) and the food type (maggot, earthworm, cricket) on the processing behavior in Triturus carnifex. We discovered that food processing, by contrast to prey capture, differed only slightly between aquatic and terrestrial habitats. However, newts adjusted the number of processing cycles to different prey types: while maggots were processed extensively, earthworm pieces were barely processed at all. We conclude that, in addition to food mechanical properties, sensory feedback such as smell and taste appear to induce flexible processing responses, while the medium in which feeding occurs appears to have less of an effect.

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