Lower Jaw Action during Prey Capture by Pelicans

The Auk ◽  
1977 ◽  
Vol 94 (4) ◽  
pp. 785-786 ◽  
Author(s):  
P. J. K. Burton
Keyword(s):  
Prey Capture ◽  
Lower Jaw

Quantitative analysis of feeding kinematics in dusky salamanders (Desmognathus)

1988 ◽  
Vol 66 (6) ◽  
pp. 1309-1317 ◽  
Author(s):  
John H. Larsen Jr. ◽  
John T. Beneski Jr.
Keyword(s):  
Quantitative Analysis ◽  
Prey Item ◽  
Prey Capture ◽  
Large Prey ◽  
Selective Force ◽  
Mandibular Symphysis ◽  
Lower Jaw ◽  
Feeding Kinematics

Gape formation by the dusky salamander (Desmognathus) involves both upper and lower jaws and occurs in a manner similar to that of other terrestrial salamanders. As Desmognathus opens its mouth, ventral rotation of the mandibles is restricted but not stopped by the atlas–mandibular ligaments; the lower jaw is not propelled anteriorly. Tongue protraction, well beyond the mandibular symphysis, is always a major component of prey capture by this genus. After the sticky tongue pad has made contact with the prey, the salamander's head surges forward and the pad is rapidly retracted with the prey item attached. Aided by a unique suite of characters the mouth then snaps shut with considerable force. Our study supports the premise that Desmognathus is no different from most, if not all, terrestrial salamanders in its employment of tongue projection as a major feature in prey capture. We argue that the primary selective force for the unique configuration of desmognathine cephalic structures was enhancement of the ability of these small salamanders to capture relatively large prey without an increase in the size of the head and body.

scholarly journals On the systematic relationships of Cearadactylus atrox, an enigmatic Early Cretaceous pterosaur from the Santana Formation of Brazil

Fossil Record ◽  
2002 ◽  
Vol 5 (1) ◽  
pp. 239-263
Author(s):  
D. M. Unwin
Keyword(s):  
Prey Capture ◽  
Anterior Part ◽  
Cervical Vertebrae ◽  
Valid Species ◽  
Basal Diameter ◽  
Diagnostic Characters ◽  
Lower Jaw ◽  
History Of ◽  
Mandibular Teeth ◽  
Santana Formation

<i>Cearadactylus atrox</i>, a large pterodactyloid pterosaur represented by an incomplete skull and lower jaw from the Lower Cretaceous Santana Formation of Brazil, is a valid species. Diagnostic characters include a mandibular symphysis with a transversely expanded "spatulate" anterior end that is considerably wider than the rostral spatula, and a third rostral tooth that has a basal diameter more than three times that of the fifth tooth. Additional diagnostic characters, contingent upon assignment of <i>Cearadactylus atrox</i> to the Ctenochasmatidae, include: anterior ends of jaws divaricate and containing 7 pairs of rostral teeth and 6 pairs of mandibular teeth; marked dimorphodonty, with an abrupt change in tooth morphology; and a "high check". "<i>Cearadactylus? ligabuei</i>" Dalla Vecchia, 1993, based on an incomplete skull, also from the Santana Formation, is not related to <i>Cearadactylus atrox</i>, exhibits several ornithocheirid synapomorphies and is referred, tentatively, to <i>Anhanguera. Cearadactylus atrox</i> exhibits various synapomorphies of the Ctenochasmatidae (rostrum anterior to nasoantorbital fenestra greater than half total skull length, teeth in anterior part of dentition relatively elongate and pencil-shaped, premaxilla has at least 7 pairs of teeth), the defining synapomorphy of the Gnathosaurinae (rostrum with dorsoventrally compressed laterally expanded spatulate anterior expansion), and shares two synapomorphies with the Chinese gnathosaurine <i>Huanhepterus quingyangensis</i> (anterior tips of jaws divaricate, teeth restricted to anterior half of mandible). Two elongate cervical vertebrae, also from the Santana Formation and previously assigned to "<i>Santanadactylus brasilensis</i>", are tentatively referred to <i>Cearadactylus</i>. Reconstruction of the temporal history of the Ctenochasmatidae suggests that while ctenochasmatines became increasingly specialised for filter feeding, gnathosaurines changed from sieve feeding to piscivory, acquiring several cranial characters that are similar to those of ornithocheirids, a group that also includes large aerial piscivores that used a terminal tooth grab for prey capture. <br><br> Cearadactylus atrox aus der Santana-Formation (Unterkreide, NO-Brasilien) ist eine valide Art. Eine Revision des Taxons, von dem ein unvollständiger Schädel mit Unterkiefer vorliegt, ergab folgende diagnostische (autapomorphe) Merkmale. Die Symphyse hat ein transversal verbreitertes spatelförmiges Vorderende, das deutlich breiter ist als das Schnauzenende. Der dritte rostrale Zahn erreicht einen basalen Durchmesser, der jenen des fünften Zahns um das Dreifache übertrifft. Hinzu kommen Merkmale, die <i>C. atrox</i> mit der Ctenochasmatidae gemein hat, darunter die vorn auseinanderklaffenden Kieferränder, sieben rostrale Zahnpaare, sechs Unterkieferzahnpaare, eine ausgeprägte Dimorphodontie sowie eine hohe Wangenregion. "<i>Cearadactylus ? ligabuei</i>" Dalla Vecchia 1993, ebenfalls mit einem unvollständigen Schädel belegt, ist nicht näher mit <i>C. atrox</i> verwandt. Im Gegensatz zu letzterem zeigt "<i>C. ? ligabuei</i>" signifikante Ähnlichkeiten mit den Ornithocheiridae. Unter Vorbehalt wird er hier der Gattung <i>Anhanguera</i> zugeordnet. <i>C. atrox</i> hat neben eindeutigen Synapomorphien der Ctenochasmatidae, z. B. erreicht das Rostrum anterior des nasoantorbitalen Fensters mehr als die halbe Schädellänge, die vordersten Zähne sind verlängert und stiftförmig und die das Prämaxillare trägt mindestens sieben Zahnpaare. Daneben besitzt <i>C. atrox</i> auch noch die entscheidende Synapomorphie der Gnathosaurinae, nämlich ein Rostrum mit dorsoventral komprimierter vorderem Auswuchs. Außerdem ist <i>C. atrox</i> gekennzeichnet durch zwei Autapomorphien des Gnathosaurinen <i>Huanhepterus quingyangensis</i> aus China: divergierende Schnauzenenden und Zähne begrenzt auf vordere Kieferhälfte. Schließlich werden zwei lange Halswirbel, die auch aus der Santana Formation stammen und bislang zu <i>Santanadactylus brasiliensis</i> gerechnet wurden, unter Vorbehalt zu <i>Cearadactylus</i> gestellt. Die Evolutionsgeschichte der Ctenochasmatidae ist durch eine zunehmende Spezialisierung auf filternde Ernährungsweise gekennzeichnet. Die Gnathosaurinen dagegen stellten sich von der filternden auf eine piscivore Ernährung um, wobei sie eine Reihe von Schädelmerkmalen erworben haben, die den Ornithocheiriden konvergent ähnlich ist. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20020050114" target="_blank">10.1002/mmng.20020050114</a>

scholarly journals A novel intramandibular joint facilitates feeding versatility in the sixbar distichodus

2022 ◽  
Author(s):  
Christopher M. Martinez ◽  
Angelly J. Tovar ◽  
Peter C. Wainwright
Keyword(s):  
Prey Capture ◽  
Teleost Fishes ◽  
Feeding Mode ◽  
Substrate Interaction ◽  
Lower Jaw ◽  
Single Structure ◽  
Jaw Protrusion ◽  
Benthic Prey ◽  
Analysis Of Motion

The intramandibular joint (IMJ) is a secondary point of movement between the two major bones of the lower jaw. It has independently evolved in several groups of teleost fishes, each time representing a departure from related species in which the mandible functions as a single structure rotating only at the quadratomandibular joint (QMJ). In this study, we examine kinematic consequences of the IMJ novelty in a freshwater characiform fish, the herbivorous Distichodus sexfasciatus. We combine traditional kinematic approaches with trajectory-based analysis of motion shapes to compare patterns of prey capture movements during substrate biting, the fish's native feeding mode, and suction of prey from the water column. We find that the IMJ enables complex jaw motions and contributes to feeding versatility by allowing the fish to modulate its kinematics in response to different prey and to various scenarios of jaw-substrate interaction. Implications of the IMJ include context-dependent movements of lower versus upper jaws, enhanced lower jaw protrusion, and the ability to maintain contact between the teeth and substrate throughout the jaw closing or biting phase of the motion. The IMJ in D. sexfasciatus appears to be an adaptation for removing attached benthic prey, consistent with its function in other groups that have evolved the joint. This study builds on our understanding of the role of the IMJ during prey capture and provides insights into broader implications of the innovative trait.

scholarly journals Rapid adaptive evolution of scale-eating kinematics to a novel ecological niche

2019 ◽  
Author(s):  
Michelle E. St. John ◽  
Roi Holzman ◽  
Christopher H. Martin
Keyword(s):  
Surface Area ◽  
Ecological Niche ◽  
Prey Capture ◽  
F1 Hybrids ◽  
Obtuse Angle ◽  
F1 Hybrid ◽  
San Salvador ◽  
Lower Jaw ◽  
Foraging Preferences ◽  
Feeding Kinematics

AbstractThe origins of novel trophic specialization, in which organisms begin to exploit novel resources for the first time, may be explained by shifts in behavior such as foraging preferences or feeding kinematics. One way to investigate the behavioral mechanisms underlying ecological novelty is by comparing prey capture kinematics between groups. In this study, we investigated the contribution of kinematics to the origins of a novel ecological niche for scale-eating within a microendemic adaptive radiation of pupfishes on San Salvador Island, Bahamas. We compared prey capture kinematics across three species of pupfish while consuming shrimp and scales in the lab and found that scale-eating pupfish exhibited peak gape sizes that were twice as large as all other groups, but also attacked prey with a more obtuse angle between their lower jaw and suspensorium. We then investigated how this variation in feeding kinematics could explain scale-biting performance by measuring the surface area removed per strike from standardized gelatin cubes. We found that a combination of larger peak gape and more obtuse lower jaw and suspensorium angles resulted in 67% more surface area removed per strike, indicating that scale-eaters may reside on a performance optimum for scale-biting. We also measured feeding kinematics of F1 hybrids to test whether feeding performance could contribute to reproductive isolation between species and found that F1 hybrid kinematics and performance more closely resembled those of generalists, suggesting that they may have low fitness in the scale-eating niche. Ultimately, our results suggest that the evolution of strike kinematics in this radiation is an adaptation to the novel niche of scale-eating.

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.

scholarly journals Scaling the feeding mechanism of largemouth bass (Micropterus salmoides): kinematics of prey capture

1995 ◽  
Vol 198 (2) ◽  
pp. 419-433 ◽  
Author(s):  
B Richard ◽  
P Wainwright
Keyword(s):  
Body Size ◽  
Largemouth Bass ◽  
High Speed ◽  
Time Course ◽  
Prey Capture ◽  
Micropterus Salmoides ◽  
Feeding Mechanism ◽  
Functional Changes ◽  
Lower Jaw ◽  
Feeding Kinematics

We present the first analysis of scaling effects on prey capture kinematics of a feeding vertebrate. The scaling of feeding kinematics of largemouth bass (Micropterus salmoides) was investigated using high-speed video (200 fields s-1) to determine what functional changes occur in the feeding mechanism as a consequence of body size. A size series of ten bass ranging from 32 to 210 mm standard length was used for the study and ten feeding sequences from each individual were analyzed to quantify movements of the feeding apparatus during prey capture. Maximal linear and angular displacements of the strike scaled isometrically. The time course of the strike was longer in larger fish. Maximal velocities of displacement were more rapid in larger fish, but their scaling exponents indicated that the intrinsic rate of muscle shortening decreased with fish size. Morphological measurements of the lever arms of the lower jaw and of the two major muscles that drive the feeding mechanism were made to relate possible biomechanical changes in the feeding mechanism to the observed kinematic relationships. The lever arms of the lower jaw and the muscles scaled isometrically; hence, the relative slowing of movements with increasing body size cannot be attributed to changes in mechanical advantage with change in body size. The scaling of feeding kinematics in the largemouth bass is in accord with the scaling of rates of muscle contraction found in other lower vertebrates. These findings demonstrate that body size can have major effects on feeding kinematics and that future comparative studies of feeding kinematics should use empirical data on size effects in kinematic comparisons between taxa.

The effects of temperature on prey-capture kinematics of the bluegill (Lepomis macrochirus): implications for feeding studies

2004 ◽  
Vol 82 (5) ◽  
pp. 794-799 ◽  
Author(s):  
A P Wintzer ◽  
P J Motta
Keyword(s):  
Water Temperature ◽  
Power Output ◽  
Prey Capture ◽  
Lepomis Macrochirus ◽  
Effect Of Temperature ◽  
Lower Jaw ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Time Required ◽  
Maximum Gape

Research with ectothermic organisms has demonstrated that temperature is positively correlated with an individual's power output during locomotion. This study investigates the effect of temperature on another aspect of power output, prey-capture kinematics, of the bluegill (Lepomis macrochirus Rafinesque, 1819). Feeding sequences for two treatments of four sunfish were filmed at three temperatures (18, 24, and 30 °C) with one treatment (A) experiencing an increasing range of temperatures and the other (B) experiencing a decreasing temperature range. Directional temperatures affected prey-capture kinematics. The time required to achieve maximum lower jaw depression and maximum gape, as well as the duration of maximum gape, time to close the mouth (from the point of maximum gape), and the total bite duration, increased as water temperature decreased. In addition, both the time to maximum gape and the time to maximum lower jaw depression were longer at 18 °C for individuals in treatment A than those in treatment B. These results indicate that water temperature can bias the results of feeding studies employing kinematics that do not control for its effects as well as those that make comparisons across such studies which utilize different temperatures and taxa.

Dominance determines fish community biomass in a temperate seagrass ecosystem

2019 ◽  
Author(s):  
Aaron Matthius Eger ◽  
Rebecca J. Best ◽  
Julia Kathleen Baum
Keyword(s):  
Species Richness ◽  
Ecosystem Function ◽  
Fish Community ◽  
Prey Capture ◽  
Fish Communities ◽  
Functional Trait ◽  
Ecosystem Functions ◽  
Community Biomass ◽  
Ecosystem Valuation ◽  
Species Abundances

Biodiversity and ecosystem function are often correlated, but there are multiple hypotheses about the mechanisms underlying this relationship. Ecosystem functions such as primary or secondary production may be maximized by species richness, evenness in species abundances, or the presence or dominance of species with certain traits. Here, we combined surveys of natural fish communities (conducted in July and August, 2016) with morphological trait data to examine relationships between diversity and ecosystem function (quantified as fish community biomass) across 14 subtidal eelgrass meadows in the Northeast Pacific (54° N 130° W). We employed both taxonomic and functional trait measures of diversity to investigate if ecosystem function is driven by species diversity (complementarity hypothesis) or by the presence or dominance of species with particular trait values (selection or dominance hypotheses). After controlling for environmental variation, we found that fish community biomass is maximized when taxonomic richness and functional evenness is low, and in communities dominated by species with particular trait values – those associated with benthic habitats and prey capture. While previous work on fish communities has found that species richness is positively correlated with ecosystem function, our results instead highlight the capacity for regionally prevalent and locally dominant species to drive ecosystem function in moderately diverse communities. We discuss these alternate links between community composition and ecosystem function and consider their divergent implications for ecosystem valuation and conservation prioritization.

Successful radiation therapy for primary cutaneous follicle center lymphoma

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Takashi Matsushita ◽  
Tomoyasu Kumano ◽  
Kazuhiko Takehara
Keyword(s):  
Radiation Therapy ◽  
Skin Biopsy ◽  
B Cell ◽  
B Cell Lymphomas ◽  
Solitary Lesion ◽  
Lower Jaw ◽  
First Choice ◽  
The Right

Primary cutaneous follicle center lymphoma (PCFCL) accounts for the majority of primary cutaneous B-cell lymphomas. We report a 60-year-old womanwith PCFCL. She had a red nodule (25 × 25 mm) on the right side of the lower jaw. She was diagnosed with PCFCL by skin biopsy. And then, she was treated with radiation therapy (total 30.6 Gy), which completely eliminated the nodule. Our case suggests that radiation therapy may be a first choice for PCFCL patients with a solitary lesion or localized lesions.    

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