scholarly journals Prey Capture Hydrodynamics in Fishes: Experimental Tests of Two Models

1983 ◽  
Vol 104 (1) ◽  
pp. 1-13 ◽  
Author(s):  
GEORGE V. LAUDER
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Regression Line ◽  
Lepomis Macrochirus ◽  
Experimental Tests ◽  
Relative Magnitude ◽  
Suction Feeding ◽  
Mouth Cavity ◽  
Large Pressure ◽  
Key Aspects

Three experimental modifications of the feeding mechanism in the bluegill sunfish (Lepomis macrochirus Rafinesque: Centrarchidae) were performed to distinguish between two alternative hydrodynamic models of the high-speed suction-feeding process in fishes. These two models make different predictions about the change in slope of the regression line representing the relationship between buccal and opercular cavity pressures, and the three experiments provide a critical test of the models. The results from all three tests unequivocally support (1) the concept of the gill bars as a resistant element within the mouth cavity functionally dividing it into buccal and opercular cavities, (2) the negligible role of lateral movement of the gill cover (operculum) in generating negative mouth cavity pressures, and (3) the large pressure differentials previously reported between the buccal and opercular cavities. Measured pressures conform neither in relative magnitude nor waveform with pressures predicted from theoretical mathematical models. Inertial effects and accelerational flows are key aspects of high-speed suction feeding.

scholarly journals Hydrodynamic regime drives flow reversals in suction feeding larval fishes during early ontogeny

2019 ◽  
Author(s):  
Krishnamoorthy Krishnan ◽  
Asif Shahriar Nafi ◽  
Roi Gurka ◽  
Roi Holzman
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Prey Capture ◽  
Sparus Aurata ◽  
Larval Fish ◽  
Fish Larvae ◽  
Numerical Models ◽  
Hydrodynamic Regime ◽  
Suction Feeding ◽  
Larval Fishes

AbstractFish larvae are the smallest self-sustaining vertebrates. As such, they face multiple challenge that stem from their minute size, and from the hydrodynamic regime in which they dwell. This regime of intermediate Reynolds numbers (Re) was shown to affect the swimming of larval fish and impede their ability to capture prey. Numerical simulations indicate that the flow fields external to the mouth in younger larvae result in shallower spatial gradients, limiting the force exerted on the prey. However, observations on feeding larvae suggest that failures in prey capture can also occur during prey transport, although the mechanism causing these failures is unclear. We combine high-speed videography and numerical simulations to investigate the hydrodynamic mechanisms that impede prey transport in larval fishes. Detailed kinematics of the expanding mouth during prey capture by larval Sparus aurata were used to parameterize age-specific numerical models of the flows inside the mouth. These models reveal that, for small larvae that slowly expand their mouth, not all the fluid that enters the mouth cavity is expelled through the gills, resulting in flow reversal at the mouth orifice. This efflux at the mouth orifice was highest in the younger ages, but was also high (>8%) in slow strikes produced by larger fish. Our modeling explains the observations of “in-and-out” events in larval fish, where prey enters the mouth but is not swallowed. It further highlights the importance of prey transport as an integral part in determining suction feeding success.

scholarly journals Biomechanics and hydrodynamics of prey capture in the Chinese giant salamander reveal a high-performance jaw-powered suction feeding mechanism

2013 ◽  
Vol 10 (82) ◽  
pp. 20121028 ◽  
Author(s):  
Egon Heiss ◽  
Nikolay Natchev ◽  
Michaela Gumpenberger ◽  
Anton Weissenbacher ◽  
Sam Van Wassenbergh
Keyword(s):  
High Speed ◽  
High Performance ◽  
Prey Capture ◽  
Three Dimensional ◽  
Cranial Morphology ◽  
Suction Feeding ◽  
Mechanical Constraints ◽  
Terrestrial Life ◽  
Chinese Giant Salamander ◽  
Dynamics Simulations

During the evolutionary transition from fish to tetrapods, a shift from uni- to bidirectional suction feeding systems followed a reduction in the gill apparatus. Such a shift can still be observed during metamorphosis of salamanders, although many adult salamanders retain their aquatic lifestyle and feed by high-performance suction. Unfortunately, little is known about the interplay between jaws and hyobranchial motions to generate bidirectional suction flows. Here, we study the cranial morphology, as well as kinematic and hydrodynamic aspects related to prey capture in the Chinese giant salamander ( Andrias davidianus ). Compared with fish and previously studied amphibians, A. davidianus uses an alternative suction mechanism that mainly relies on accelerating water by separating the ‘plates’ formed by the long and broad upper and lower jaw surfaces. Computational fluid dynamics simulations, based on three-dimensional morphology and kinematical data from high-speed videos, indicate that the viscerocranial elements mainly serve to accommodate the water that was given a sufficient anterior-to-posterior impulse beforehand by powerful jaw separation. We hypothesize that this modified way of generating suction is primitive for salamanders, and that this behaviour could have played an important role in the evolution of terrestrial life in vertebrates by releasing mechanical constraints on the hyobranchial system.

Do flatfish feed like other fishes? A comparative study of percomorph prey-capture kinematics.

1997 ◽  
Vol 200 (22) ◽  
pp. 2841-2859 ◽  
Author(s):  
A Gibb
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Multivariate Analyses ◽  
Lepomis Macrochirus ◽  
Experimental Methodology ◽  
Flatfish Species ◽  
Significant Difference ◽  
Jaw Protrusion ◽  
Suction Index ◽  
Post Hoc

The kinematics of prey capture in two bilaterally asymmetrical pleuronectiform flatfish species (Pleuronichthys verticalis and Xystreurys liolepis) and two symmetrical percomorph species (Lepomis macrochirus, a centrarchid, and Cheilinus digrammus, a labrid) were compared to test the hypothesis that flatfish have distinct prey-capture kinematics from those quantified for other percomorph fishes. Size-matched individuals of both flatfish species were video-taped feeding using a high-speed video system. Cephalic displacement and timing variables were quantified and compared with data from similarly sized L. macrochirus and C. digrammus previously collected by other researchers using similar experimental methodology. Nested multivariate analyses of variance indicated that there was no significant difference in prey-capture kinematics between flatfish and non-flatfish taxa, but that prey-capture kinematics did differ among the four taxa. Multiple nested analyses of variance revealed that the taxa differed in 7 of 11 kinematic variables. Post-hoc tests and comparisons with other fish taxa suggest that individuals of P. verticalis possess an unusual combination of prey-capture kinematics including large hyoid depression, large neurocranial rotation, large upper jaw protrusion and small gape. Previous research has suggested that this combination of traits is associated with suction-based prey capture. Correspondingly, the ram­suction index calculated for P. verticalis is more negative (indicating a greater use of suction) than that calculated for the other taxa. When homologous kinematic variables are compared across these four taxa, flatfish do not appear to have similar prey-capture kinematics. However, both flatfish species are distinct from the two symmetrical percomorph species in their asymmetrical jaw movements.

scholarly journals Ontogeny of feeding morphology and kinematics in juvenile fishes: a case study of the cottid fish Clinocottus analis

1996 ◽  
Vol 199 (9) ◽  
pp. 1961-1971
Author(s):  
A Cook
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Least Squares Regression ◽  
Suction Feeding ◽  
Juvenile Period ◽  
Feeding Mode ◽  
Feeding Morphology ◽  
Suction Index ◽  
And Behavior

The development of feeding morphology, kinematics and behavior was examined in the juveniles of the cottid fish Clinocottus analis. The attacks of 18 juvenile C. analis, between 17.59 mm and 42.15 mm in standard length (SL), feeding on brown worms were filmed using high-speed video. Feeding mode, ram- or suction-dominated, kinematic variables and morphology were quantified and compared over the juvenile period. The analysis of these three factors was based on the following questions: (1) do they change over ontogeny; (2) how do their values compare with those of larvae, juveniles and adults of other species; and (3) what is the level of stereotypy, as measured by the variance in these factors, at this stage in ontogeny and does it change? Small C. analis juveniles have the small gape and large buccal cavity of a suction feeder, and this morphology becomes more pronounced as they become larger. The kinematic variables of C. analis juveniles are similar to those of adult suction-feeding cottids and least-squares regression analysis showed significant changes in only two variables (time to prey capture and absolute attack predator­prey distance) over the juvenile period. Feeding mode, as measured by the ram-suction index, shows an increase in the suction component of the strike with increasing size. This study demonstrates that, in C. analis, suction feeding behavior develops during the juvenile period. Within the juvenile stage, morphology, prey-capture kinematics and feeding mode are not tightly linked ontogenetically such that suction-feeder kinematics (short predator­prey distance and low attack velocity) and basic morphology (small gape, large buccal volume) develop much earlier than the employment of a large suction component during the strike.

scholarly journals Size does matter – Intraspecific variation of feeding mechanics in the crested newt Triturus dobrogicus (Kiritzescu, 1903)

2018 ◽  
Vol 5 (1) ◽  
pp. 75-85
Author(s):  
Florian Kucera ◽  
Christian J. Beisser ◽  
Patrick Lemell
Keyword(s):  
Body Size ◽  
High Speed ◽  
Prey Capture ◽  
Buccal Cavity ◽  
Danube Delta ◽  
Suction Feeding ◽  
Crested Newt ◽  
Feeding Mechanics ◽  
Feeding Process ◽  
Salamander Species

AbstractMany studies have yet been conducted on suction feeding in aquatic salamander species. Within the Salamandridae, the crested newtTriturus dobrogicus(Kiritzescu, 1903), occurring from the Austrian Danube floodplains to the Danube Delta, was not subject of investigations so far. The present study examines the kinematics of aquatic suction feeding in this species by means of high-speed videography. Recordings of five individuals of different size and sex while feeding on bloodworms were conducted, in order to identify potential discrepancies among individuals and sizes. Five coordinate points were digitized from recordings of prey capture and twelve time- and velocity-determined variables were evaluated. All specimens follow a typical inertial suction feeding process, where rapid hyoid depression expands the buccal cavity. Generated negative pressure within the buccal cavity causes influx of water along with the prey item into the mouth. Results demonstrate higher distance values and angles for gape in individuals with smaller size. In addition, hyoid depression is maximized in smaller individuals. WhileTriturus dobrogicusresembles a typical inertial suction feeder in its functional morphology, intraspecific differences could be found regarding the correlation of different feeding patterns and body size.

scholarly journals Kinematics of feeding in bluegill sunfish: is there a general distinction between aquatic capture and transport behaviors?

1995 ◽  
Vol 198 (3) ◽  
pp. 709-720 ◽  
Author(s):  
G Gillis ◽  
G Lauder
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Lepomis Macrochirus ◽  
Ambystoma Tigrinum ◽  
Bluegill Sunfish ◽  
Lower Vertebrate ◽  
Terrestrial Vertebrates ◽  
Aquatic Vertebrates ◽  
Food Transport ◽  
Nested Analysis

Despite numerous studies of food transport in terrestrial vertebrates, little is known about this aspect of the feeding repertoire in aquatic vertebrates. Previous work had predicted that the kinematics of aquatic prey capture by suction feeding should be similar to those of prey transport. However, recent analyses of aquatic prey capture and transport in the tiger salamander Ambystoma tigrinum have contradicted this hypothesis, and document numerous differences between these two behaviors. In this study, using high-speed video and statistical analyses, we compare prey capture and transport kinematics in a ray-finned fish (Lepomis macrochirus, the bluegill sunfish) to examine the generality of differences between capture and transport behaviors in aquatic vertebrates. Compared with prey capture, prey transport is significantly more rapid and tends to have reduced lower jaw excursions, while having similar hyoid movements. A nested analysis of variance was used to analyze six variables common to both this analysis of Lepomis macrochirus and a previous study of Ambystoma tigrinum; none of these six variables showed significant variation between taxa. These results indicate that aquatic prey transport is kinematically distinct from capture behavior and that the distinctions between these two behaviors are remarkably consistent in two phylogenetically divergent lower vertebrate taxa. Such consistent kinematic differences have not been found in amniote taxa studied to date, but may constitute a plesiomorphic feature of vertebrate feeding systems.

scholarly journals Water Flow Patterns During Prey Capture by Teleost Fishes

1984 ◽  
Vol 113 (1) ◽  
pp. 143-150 ◽  
Author(s):  
GEORGE V. LAUDER ◽  
BRIAN D. CLARK
Keyword(s):  
Water Flow ◽  
Prey Capture ◽  
Flow Patterns ◽  
The Body ◽  
Teleost Fishes ◽  
Small Particles ◽  
Suction Feeding ◽  
Mouth Cavity

Water flow into the mouth cavity during suction feeding in centrarchid sunfishes was studied by mapping the trajectories of small particles in the water during prey capture. In Lepomis, a circulation develops as the mouth opens, and water is drawn into the mouth from above, below and in front of the head. Water displaced by movement of the body as the prey is approached during the strike is entrained into the circulation towards the mouth. The parcel of water sucked into the mouth has a diameter approximately one-tenth that of the predator's length.

The Suction Feeding Mechanism in Sunfishes (Lepomis): An Experimental Analysis

1980 ◽  
Vol 88 (1) ◽  
pp. 49-72 ◽  
Author(s):  
GEORGE V. LAUDER
Keyword(s):  
Negative Pressure ◽  
High Speed ◽  
Prey Capture ◽  
Mouth Opening ◽  
Positive Phase ◽  
Positive Pressure ◽  
Pressure Reduction ◽  
Hydrodynamic Models ◽  
Suction Feeding ◽  
Pressure Magnitude

The process of prey capture by inertial suction was studied in three species of sunfishes (Lepomis auritus, L. macrochirus, and L. gibbosus) by the simultaneous recording of buccal and opercular cavity pressures in order to test current hydrodynamic models of feeding in fishes. Synchronous high-speed films permitted the correlation of kinematic patterns of jaw bone movement with specific pressure waveforms. Opercular cavity pressures averaged onefifth buccal pressures and pressure magnitude was correlated with prey type. Peak buccal and opercular pressures were −650 cm H2O and −150 cm H2O respectively; peak rate of pressure change was −100 cm H2O/ms. Buccal pressure magnitude varied inversely with degree of predator satiation. Opercular pressure waveforms have an initial positive phase followed by a prolonged negative phase and then a final positive phase. The initial positive pressure may be absent during slow strikes at worms. Buccal pressure waveforms show considerable variability. The modal waveform consists of a sharp negative pressure pulse followed by a positive phase and finally by another pressure reduction. Delayed opercular abduction relative to mouth cavity compression correlates with the presence of a positive buccal phase. The second buccal negative pressure is the result of rapid mouth closing causing a pressure reduction (water hammer effect) as water flow continues posteriorly. These data indicate that (1) the buccal and opercular cavities are functionally separated by a gill curtain of high resistance, (2) that inertial effects of water are important in the description of the suction feeding process, (3) that a reverse flow of water (opercular to buccal cavity) may occur during the early phase of mouth opening prior to establishment of a buccal to opercular flow regime, and (4) current models of respiratory pressure and flow pattern cannot be applied to feeding. Current hydrodynamic models of suction feeding in fishes are re-evaluated in the light of this analysis.

Yaw Galloping of a TLWP Platform Under High Speed Currents by Analytical Methods and its Comparison With Experimental Results

2017 ◽  
Author(s):  
Francisco Lamas ◽  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes
Keyword(s):  
High Speed ◽  
Production Systems ◽  
Experimental Tests ◽  
Experimental Results ◽  
Analytical Methodology ◽  
New Approach ◽  
Laboratory Facilities ◽  
Polynomial Curve ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses

Flow Induced Motions are always an important subject during both design and operational phases of an offshore platform life. These motions could significantly affect the performance of the platform, including its mooring and oil production systems. These kind of analyses are performed using basically two different approaches: experimental tests with reduced models and, more recently, with Computational Fluid Dynamics (CFD) dynamic analysis. The main objective of this work is to present a new approach, based on an analytical methodology using static CFD analyses to estimate the response on yaw motions of a Tension Leg Wellhead Platform on one of the several types of motions that can be classified as flow-induced motions, known as galloping. The first step is to review the equations that govern the yaw motions of an ocean platform when subjected to currents from different angles of attack. The yaw moment coefficients will be obtained using CFD steady-state analysis, on which the yaw moments will be calculated for several angles of attack, placed around the central angle where the analysis is being carried out. Having the force coefficients plotted against the angle values, we can adjust a polynomial curve around each analysis point in order to evaluate the amplitude of the yaw motion using a limit cycle approach. Other properties of the system which are flow-dependent, such as damping and added mass, will also be estimated using CFD. The last part of this work consists in comparing the analytical results with experimental results obtained at the LOC/COPPE-UFRJ laboratory facilities.

scholarly journals Effect of Bottom Geometry on the Natural Sloshing Motion of Water Inside Tanks: An Experimental Analysis

2021 ◽  
Vol 11 (2) ◽  
pp. 605
Author(s):  
Antonio Agresta ◽  
Nicola Cavalagli ◽  
Chiara Biscarini ◽  
Filippo Ubertini
Keyword(s):  
Energy Dissipation ◽  
Water Depth ◽  
Shear Force ◽  
Experimental Tests ◽  
Shear Load ◽  
Damping Properties ◽  
Base Shear ◽  
Structure Interaction ◽  
Sloshing Phenomenon ◽  
Key Aspects

The present work aims at understanding and modelling some key aspects of the sloshing phenomenon, related to the motion of water inside a container and its effects on the substructure. In particular, the attention is focused on the effects of bottom shapes (flat, sloped and circular) and water depth ratio on the natural sloshing frequencies and damping properties of the inner fluid. To this aim, a series of experimental tests has been carried out on tanks characterised by different bottom shapes installed over a sliding table equipped with a shear load cell for the measurement of the dynamic base shear force. The results are useful for optimising the geometric characteristics of the tank and the fluid mass in order to obtain enhanced energy dissipation performances by exploiting fluid–structure interaction effects.

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