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.

Prey-capture behavior in gymnotid electric fish: motion analysis and effects of water conductivity

2001 ◽  
Vol 204 (3) ◽  
pp. 543-557 ◽  
Author(s):  
M.A. MacIver ◽  
N.M. Sharabash ◽  
M.E. Nelson
Keyword(s):  
Prey Capture ◽  
Body Position ◽  
Sensory Information ◽  
Orienting Response ◽  
Signal Acquisition ◽  
Three Dimensional Model ◽  
Water Conductivity ◽  
Detection Distance ◽  
Surrounding Water ◽  
Prey Capture Behavior

Animals can actively influence the content and quality of sensory information they acquire from the environment through the positioning of peripheral sensory surfaces. This study investigated receptor surface positioning during prey-capture behavior in weakly electric gymnotiform fish of the genus Apteronotus. Infrared video techniques and three-dimensional model-based tracking methods were used to provide quantitative information on body position and conformation as black ghost (A. albifrons) and brown ghost (A. leptorhynchus) knifefish hunted for prey (Daphnia magna) in the dark. We found that detection distance depends on the electrical conductivity of the surrounding water. Best performance was observed at low water conductivity (2.8 cm mean detection distance and 2 % miss rate at 35 microS cm(−)(1), A. albifrons) and poorest performance at high conductivity (1.5 cm mean detection distance and 11 % miss rate at 600 microS cm(−)(1), A. albifrons). The observed conductivity-dependence implies that nonvisual prey detection in Apteronotus is likely to be dominated by the electrosense over the range of water conductivities experienced by the animal in its natural environment. This result provides the first evidence for the involvement of electrosensory cues in the prey-capture behavior of gymnotids, but it leaves open the possibility that both the high-frequency (tuberous) and low-frequency (ampullary) electroreceptors may contribute. We describe an electrosensory orienting response to prey, whereby the fish rolls its body following detection to bring the prey above the dorsum. This orienting response and the spatial distribution of prey at the time of detection highlight the importance of the dorsal surface of the trunk for electrosensory signal acquisition. Finally, quantitative analysis of fish motion demonstrates that Apteronotus can adapt its trajectory to account for post-detection motion of the prey, suggesting that it uses a closed-loop adaptive tracking strategy, rather than an open-loop ballistic strike strategy, to intercept the prey.

Prey capture in the chain pickerel, Esox niger: correlations between feeding and locomotor behavior

1981 ◽  
Vol 59 (6) ◽  
pp. 1072-1078 ◽  
Author(s):  
David M. Rand ◽  
George V. Lauder
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Mouth Opening ◽  
Predatory Behavior ◽  
Jaw Movements ◽  
Suction Velocity ◽  
Locomotor Pattern ◽  
Mechanical Unit ◽  
High Speed Cinematography ◽  
Locomotor Patterns

The predatory behavior of the chain pickerel Esox niger was studied by high-speed cinematography to correlate patterns of jaw bone movement with locomotor patterns. Pattern B strikes were initiated at significantly shorter distances from the prey, had higher acceleration rates, and the velocity of mouth opening and suspensorial abduction was greater than for pattern A strikes. No difference was found in the excursion amplitudes of jaw movements between pattern A and pattern B strikes. Significant differences were found between midwater and corner strikes in the amplitude of mouth opening and hyoid depression: both were smaller in corner attacks and suction velocity was higher. Both velocity and amplitude of each mechanical unit in the head can be varied depending on the locomotor pattern and the position of the prey.

scholarly journals A dedicated visual pathway for prey detection in larval zebrafish

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Julia L Semmelhack ◽  
Joseph C Donovan ◽  
Tod R Thiele ◽  
Enrico Kuehn ◽  
Eva Laurell ◽  
...  
Keyword(s):  
Optic Tectum ◽  
Moving Objects ◽  
Prey Capture ◽  
Ganglion Cells ◽  
Sensory Information ◽  
Neural Mechanism ◽  
Medial Longitudinal Fasciculus ◽  
Visual Stream ◽  
Two Photon ◽  
Prey Capture Behavior

Zebrafish larvae show characteristic prey capture behavior in response to small moving objects. The neural mechanism used to recognize objects as prey remains largely unknown. We devised a machine learning behavior classification system to quantify hunting kinematics in semi-restrained animals exposed to a range of virtual stimuli. Two-photon calcium imaging revealed a small visual area, AF7, that was activated specifically by the optimal prey stimulus. This pretectal region is innervated by two types of retinal ganglion cells, which also send collaterals to the optic tectum. Laser ablation of AF7 markedly reduced prey capture behavior. We identified neurons with arbors in AF7 and found that they projected to multiple sensory and premotor areas: the optic tectum, the nucleus of the medial longitudinal fasciculus (nMLF) and the hindbrain. These findings indicate that computations in the retina give rise to a visual stream which transforms sensory information into a directed prey capture response.

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.

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.

The Kinematics of Prey Capture and the Mechanism of Tongue Protraction in the Green Tree Frog Hyla Cinerea

1992 ◽  
Vol 170 (1) ◽  
pp. 235-256 ◽  
Author(s):  
STEPHEN M. DEBAN ◽  
KIISA C. NISHIKAWA
Keyword(s):  
Kinematic Analysis ◽  
High Speed ◽  
Prey Capture ◽  
Tree Frog ◽  
Hyla Cinerea ◽  
The Family ◽  
Before And After ◽  
Prey Capture Behavior

Prey capture was studied in the green tree frog (Hyla cinerea) before and after denervation of either the m. genioglossus or m. submentalis using high-speed videography and kinematic analysis. The prey capture behavior and extent of tongue protraction of several members of the subfamilies Hylinae, Pelodryadinae and Phyllomedusinae were also studied. Results show that the m. genioglossus is necessary to produce complete tongue protraction and that the m. submentalis is necessary for mandibular bending, but not necessary for complete tongue protraction in Hyla cinerea. The tongue of Hyla cinerea resembles the weakly protrusible tongues of the archaeobatrachian frogs Ascaphus and Discoglossus more than the highly protrusible tongues of other neobatrachians, such as Rana or Bufo. A weakly protrusible tongue is present in the subfamilies Hylinae and Pelodryadinae, and a highly protrusible tongue is present in the subfamily Phyllomedusinae. These results suggest that hyline and pelodryadine hylids have retained the ancestral anuran tongue morphology and that highly protrusible tongues have evolved once within the family Hylidae, in the subfamily Phyllomedusinae.

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.

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.

Predatory behaviour and prey-capture decision-making by the web-weaving spider Micrathena sagittata

2005 ◽  
Vol 83 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Francisco Díaz-Fleischer
Keyword(s):  
Prey Item ◽  
Prey Capture ◽  
Prey Size ◽  
Prey Type ◽  
Optimal Foraging Theory ◽  
Choice Test ◽  
Large Prey ◽  
Predatory Behaviour ◽  
Hunting Behaviour ◽  
The Web

Optimal-foraging theory predicts how a predator would feed most efficiently when faced with a choice of two types of prey differing in profitability and density in the habitat. The predator should focus only on the more profitable prey, since any prey item eaten by the predator has a cost in terms of the time and resources taken to subdue and eat it. A study of the hunting behaviour and prey-type selection of the web-weaving spider Micrathena sagittata (Walckenaer, 1841) (Araneae: Araneidae) in the field is documented. In the first part of the study, prey of two sizes were offered in four sectors of the web (top, bottom, right, and left). A prey item was provided at one position of the web at a time. Attack time was recorded at each position. Also, choice and no-choice tests were carried out by offering prey in opposing web sectors (top and bottom) simultaneously. Large prey were more successfully captured in the upper parts than in the bottom parts of the web. In the choice test, spiders always preferred large prey to small prey, while in the no-choice test, spiders always responded to the first stimulus received. Two different attack strategies, depending on prey size, were observed. Hunting strategies and prey-size preference can be related to the cost of web construction and profitability of the prey type.

scholarly journals Prey Capturing Dynamics and Nanomechanically Graded Cutting Apparatus of Dragonfly Nymph

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 559
Author(s):  
Lakshminath Kundanati ◽  
Prashant Das ◽  
Nicola M. Pugno
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
High Speed ◽  
Prey Capture ◽  
High Speed Photography ◽  
Sensory Organs ◽  
Dragonfly Nymph ◽  
Drag Forces ◽  
Predatory Insects ◽  
Dragonfly Nymphs

Aquatic predatory insects, like the nymphs of a dragonfly, use rapid movements to catch their prey and it presents challenges in terms of movements due to drag forces. Dragonfly nymphs are known to be voracious predators with structures and movements that are yet to be fully understood. Thus, we examine two main mouthparts of the dragonfly nymph (Libellulidae: Insecta: Odonata) that are used in prey capturing and cutting the prey. To observe and analyze the preying mechanism under water, we used high-speed photography and, electron microscopy. The morphological details suggest that the prey-capturing labium is a complex grasping mechanism with additional sensory organs that serve some functionality. The time taken for the protraction and retraction of labium during prey capture was estimated to be 187 ± 54 ms, suggesting that these nymphs have a rapid prey mechanism. The Young’s modulus and hardness of the mandibles were estimated to be 9.1 ± 1.9 GPa and 0.85 ± 0.13 GPa, respectively. Such mechanical properties of the mandibles make them hard tools that can cut into the exoskeleton of the prey and also resistant to wear. Thus, studying such mechanisms with their sensory capabilities provides a unique opportunity to design and develop bioinspired underwater deployable mechanisms.

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