The mechanics of prey prehension in chameleons

2000 ◽  
Vol 203 (21) ◽  
pp. 3255-3263 ◽  
Author(s):  
A. Herrel ◽  
J.J. Meyers ◽  
P. Aerts ◽  
K.C. Nishikawa
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Prey Size ◽  
Nerve Transection ◽  
Surface Phenomena ◽  
High Speed Video ◽  
Video Recordings ◽  
Tongue Muscles ◽  
Stimulation Experiments ◽  
Prey Items

Iguanian lizards generally use their tongue to capture prey. Because lingual prehension is based on surface phenomena (wet adhesion, interlocking), the maximal prey size that can be captured is small. However, published records show that prey items eaten by chameleons include small vertebrates such as lizards and birds, indicating that these lizards are using a different prey prehension mechanism. Using high-speed video recordings, cineradiography, electromyography, nerve transection and stimulation experiments, we investigated the function of the tongue during prey capture. The results of these experiments indicate that chameleons have modified the primitive iguanian system by including a suction component in their prehension mechanism. Suction is generated by the activity of two modified intrinsic tongue muscles that pull the tongue pad inwards. Moreover, we demonstrate that the mechanism described here is a prerequisite for successful feeding.

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.

Calibration of Stopwatches by Utilizing High Speed Video Recordings and a Synchronous Counter

NCSLI Measure ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 64-71 ◽  
Author(s):  
C. M. Tsui ◽  
Y. K. Yan ◽  
H. M. Chan
Keyword(s):  
High Speed ◽  
High Speed Video ◽  
Video Recordings

scholarly journals Debunking the viper's strike: harmless snakes kill a common assumption

2016 ◽  
Vol 12 (3) ◽  
pp. 20160011 ◽  
Author(s):  
David A. Penning ◽  
Baxter Sawvel ◽  
Brad R. Moon
Keyword(s):  
High Speed ◽  
Past Century ◽  
Loss Of Consciousness ◽  
Common Assumption ◽  
Motor Responses ◽  
High Speed Video ◽  
The Past ◽  
Venomous Snakes ◽  
Video Recordings ◽  
Very High

To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non-vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers, western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: the accelerations exceed values that can cause loss of consciousness in other animals, such as the accelerations experienced by jet pilots during extreme manoeuvres, and they make the strikes faster than the sensory and motor responses of mammalian prey and predators. Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move.

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.

Feeding kinematics of juvenile swellsharks, Cephaloscyllium ventriosum

1997 ◽  
Vol 200 (8) ◽  
pp. 1255-1269 ◽  
Author(s):  
L Ferry-Graham
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Buccal Cavity ◽  
Video Recording ◽  
Large Prey ◽  
Feeding Behaviors ◽  
Suction Index ◽  
Item Size ◽  
Prey Items ◽  
Cephaloscyllium Ventriosum

To investigate how feeding behaviors change with prey size, high-speed video recording was used to examine the kinematics of prey capture and transport in 1-year-old swellsharks Cephaloscyllium ventriosum (Scyliorhinidae: Carchariniformes) feeding on two differently sized prey items. Prey capture in these sharks generally consisted of an initially ram-dominated capture bite, one or more manipulation bites, a holding phase during which the food was held in the teeth of the shark, and then suction-dominated prey transport. During initial capture and transport, most of the water taken in is forced back out of the mouth anteriorly rather than continuing posteriorly out through the gill openings. Dye experiments in which dye-perfused prey items were ingested by the sharks confirm this observation; distinct jets of colored water were video-taped as they were ejected from the mouth. Very late in prey transport, a bolus of water is ejected through the gill slits; however, by this time, the majority of water appears already to have exited the buccal cavity through the mouth. Such patterns were observed for sharks feeding on both small and large prey items. Although a basic pattern of prey capture and transport was regularly repeated among strikes, kinematic patterns during prey capture and transport were variable both within and among individuals, indicating that prey acquisition is not tightly controlled. However, the amount of variability was similar among prey sizes. In addition, there were no detectable changes in behavior due to prey item size. Ram-suction index values confirmed that similar capture modes were being utilized for both prey sizes.

Terrestrial locomotion in the black-billed magpie: kinematic analysis of walking, running and out-of-phase hopping

2000 ◽  
Vol 203 (14) ◽  
pp. 2159-2170 ◽  
Author(s):  
M. Verstappen ◽  
P. Aerts ◽  
R. Van Damme
Keyword(s):  
Kinematic Analysis ◽  
High Speed ◽  
Bird Species ◽  
Pica Pica ◽  
Terrestrial Locomotion ◽  
High Speed Video ◽  
Video Recordings ◽  
Flexion Extension

The inter-limb kinematic patterns of walking, running and out-of-phase hopping in black-billed magpies (Pica pica) were studied using high-speed video recordings. The flexion/extension patterns of the joints were similar between the gait types, suggesting that the within-leg control of the angular excursions is similar. This result is further supported by the fact that running and hopping are alternative gaits at speeds higher than walking; however, magpies show a preference for hopping. Moreover, only small differences occur between the kinematic patterns of the two limbs during out-of-phase hopping, during which the legs are believed to have different functions. The hindlimb kinematic patterns of magpies are like those of other flying and more terrestrial bird species; however, striking differences are found in comparison with humans at the level of the internal angles. This is probably due to the differences in the morphology and configuration of their legs.

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