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 Hydrodynamic regime determines the feeding success of larval fish through the modulation of strike kinematics

2017 ◽  
Vol 284 (1853) ◽  
pp. 20170235 ◽  
Author(s):  
Victor China ◽  
Liraz Levy ◽  
Alex Liberzon ◽  
Tal Elmaliach ◽  
Roi Holzman
Keyword(s):  
High Speed ◽  
Sparus Aurata ◽  
Larval Fish ◽  
Reynolds Numbers ◽  
Early Ontogeny ◽  
Hydrodynamic Regime ◽  
Physical Growth ◽  
Larval Feeding ◽  
Feeding Success ◽  
Order Of Magnitude

Larval fishes experience extreme mortality rates, with 99% of a cohort perishing within days after starting to actively feed. While recent evidence suggests that hydrodynamic factors contribute to constraining larval feeding during early ontogeny, feeding is a complex process that involves numerous interacting behavioural and biomechanical components. How these components change throughout ontogeny and how they contribute to feeding remain unclear. Using 339 observations of larval feeding attempts, we quantified the effects of morphological and behavioural traits on feeding success of Sparus aurata larvae during early ontogeny. Feeding success was determined using high-speed videography, under both natural and increased water viscosity treatments. Successful strikes were characterized by Reynolds numbers that were an order of magnitude higher than those of failed strikes. The pattern of increasing strike success with increasing age was driven by the ontogeny of traits that facilitate the transition to higher Reynolds numbers. Hence, the physical growth of a larva plays an important role in its transition to a hydrodynamic regime of higher Reynolds numbers, in which suction feeding is more effective.

Consequences of plume encounter on larval fish growth and condition in the Gulf of Mexico

2020 ◽  
Vol 650 ◽  
pp. 63-80 ◽  
Author(s):  
KE Axler ◽  
S Sponaugle ◽  
F Hernandez ◽  
C Culpepper ◽  
RK Cowen
Keyword(s):  
Gulf Of Mexico ◽  
Continental Shelf ◽  
Prey Capture ◽  
Larval Fish ◽  
Fish Larvae ◽  
Fish Growth ◽  
Frequency Distributions ◽  
Larval Fishes ◽  
River Estuarine ◽  
Anchoa Hepsetus

Freshwater input into nearshore continental shelf waters from coastal river-estuarine plumes can greatly alter the physical and trophic environments experienced by fish larvae. However, the biological consequences of plume encounter on larval fish survival remain equivocal, largely due to the extreme variability of these systems but also because traditional sampling techniques alone are too coarse to effectively characterize the dynamic biophysical environment at spatiotemporal scales relevant to individual larvae. Using a multidimensional approach, we simultaneously collected in situ imagery and net samples of larval fishes and zooplankton from the Mobile Bay plume (Alabama, USA) and ambient continental shelf waters during a high discharge event (8-11 April 2016). We measured the effects of plume encounter on growth and condition of larval striped anchovy Anchoa hepsetus and sand seatrout Cynoscion arenarius, 2 prominent nearshore species in the northern Gulf of Mexico. Size-frequency distributions of both species indicated that larger individuals were present in shelf waters but absent from plume waters. Otolith microstructure analysis revealed that recent growth of both focal species was significantly lower for plume-collected larvae during the last few days prior to capture. Furthermore, plume larvae were in poorer morphometric condition (skinnier at length) than their shelf counterparts, despite the fact that there were higher concentrations of zooplankton prey in plume water masses. Taken together, these results suggest that elevated prey concentrations do not necessarily translate to higher growth and condition. High turbulence and turbidity within the plume may physically inhibit the prey capture ability and feeding success of fish larvae.

scholarly journals The hydrodynamic regime drives flow reversals in suction-feeding larval fishes during early ontogeny

2020 ◽  
Vol 223 (9) ◽  
pp. jeb214734 ◽  
Author(s):  
Krishnamoorthy Krishnan ◽  
Asif Shahriar Nafi ◽  
Roi Gurka ◽  
Roi Holzman
Keyword(s):  
Early Ontogeny ◽  
Hydrodynamic Regime ◽  
Suction Feeding ◽  
Larval Fishes ◽  
Flow Reversals

Modeling of Fabric Impact With High Speed Imaging and Nickel-Chromium Wires Validation

2011 ◽  
Vol 78 (5) ◽  
Author(s):  
Sidney Chocron ◽  
Trenton Kirchdoerfer ◽  
Nikki King ◽  
Christopher J. Freitas
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Numerical Models ◽  
Single Layer ◽  
Diagnostic Techniques ◽  
High Speed Photography ◽  
High Speed Imaging ◽  
Nickel Chromium ◽  
Validation Set ◽  
The Waves

Ballistic tests were performed on single-yarn, single-layer and ten-layer targets of Kevlar® KM2 (600 and 850 denier), Dyneema® SK-65 and PBO® (500 denier). The objective was to develop data for validation of numerical models so, multiple diagnostic techniques were used: (1) ultra-high speed photography, (2) high-speed video and (3) nickel-chromium wire technique. These techniques allowed thorough validation of the numerical models through five different paths. The first validation set was at the yarn level, where the transverse wave propagation obtained with analytical and numerical simulations was compared to that obtained in the experiments. The second validation path was at the single-layer level: the propagation of the pyramidal wave observed with the high speed camera was compared to the numerical simulations. The third validation consisted of comparing, for the targets with ten layers, the pyramid apex and diagonal positions from tests and simulations. The fourth validation, which is probably the most relevant, consisted of comparing the numerical and experimental ballistic limits. Finally for the fifth validation set, nickel-chromium wires were used to record electronically the waves propagating in the fabrics. It is shown that for the three materials the waves recorded during the tests match well the waves predicted by the numerical model.

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 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.

Evaluation of in situ Enclosures for Larval Fish Studies

1987 ◽  
Vol 44 (1) ◽  
pp. 54-65 ◽  
Author(s):  
Yves de Lafontaine ◽  
William C. Leggett
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Low Cost ◽  
Experimental Studies ◽  
Size Composition ◽  
Surrounding Water ◽  
Larval Fishes ◽  
Plastic Bags ◽  
Capelin Mallotus Villosus

Two in situ enclosure designs intended for use in larval fish studies were evaluated for their capability to reproduce and track the physical properties of the surrounding water and to maintain the behavioral characteristics of enclosed organisms. The enclosures, which were constructed of porous material, allowed near instantaneous response to natural variations in temperature, salinity, and dissolved oxygen at all depths. Phytoplankton biomass inside the enclosures was less variable than that observed outside and its size composition was related to the porosity of the material used. Particle sinking rates inside the enclosures were much lower than those previously reported for plastic bags, suggesting a higher degree of turbulence in our enclosures. Newly hatched larval capelin (Mallotus villosus) and Zooplankton stocked into the enclosures exhibited diel migration of amplitude similar to that observed in the field. Zooplankton were more homogeneously distributed than fish larvae although heterogeneity decreased at night for both taxa. Low cost, ease of handling, environmental reproducibility, and quality of replication provided by the enclosures make them particularly appropriate for replicated experimental studies of the interactions between larval fishes, their predators, and prey.

scholarly journals Behavior of Beam-to-Column Connections with Angles. Part 2-Numerical Analysis

2016 ◽  
Vol 6 (1) ◽  
pp. 35-40
Author(s):  
M. Ghindea ◽  
A. Cătărig ◽  
R. Ballok
Keyword(s):  
Numerical Simulations ◽  
Deformation Process ◽  
High Speed ◽  
Rotation Curve ◽  
Numerical Models ◽  
Experimental Tests ◽  
3D Models ◽  
Experimental Investigations ◽  
Software Packages ◽  
Parametric Studies

Abstract Based on the results of experimental tests, presented in the first part of this paper, Part 1-Experimental Investigations (Ghindea M., Catarig A., Ballok R.) advanced numerical simulations were performed using FEM based software Abaqus. The recently arise of high speed computers and advanced FEM software packages allow to create and solve extensively detailed 3D models. The aim of this second part of the paper is to develop accurate FEM models for better approach of the studied beam-to-column connections. The paper presents the designed numerical models and the results for four bolted beam-to-column connections using top-and-seat and/or web angle cleats, in different configurations. The objective of this paper is to achieve functional numerical models which, by faithfully running, reproduce the experimental results. Thus, calibrating the numerical results with the experimental ones it can be perform then parametric studies, achieving reliable results for similar configurations of joints. The results obtained after numerical simulations were compared with experimental data. The behavior moment-rotation curve and the deformation process of the experimental captured specimens were virtually reproduced with minimum deviation.

Locomotor repertoire of the larval zebrafish: swimming, turning and prey capture

2000 ◽  
Vol 203 (17) ◽  
pp. 2565-2579 ◽  
Author(s):  
S.A. Budick ◽  
D.M. O'Malley
Keyword(s):  
High Speed ◽  
Neural Control ◽  
Prey Capture ◽  
Larval Fish ◽  
Large Angle ◽  
Cellular Level ◽  
Behavior Patterns ◽  
Brachydanio Rerio ◽  
Larval Zebrafish

Larval zebrafish (Brachydanio rerio) are a popular model system because of their genetic attributes, transparency and relative simplicity. They have approximately 200 neurons that project from the brainstem into the spinal cord. Many of these neurons can be individually identified and laser-ablated in intact larvae. This should facilitate cellular-level characterization of the descending control of larval behavior patterns. Towards this end, we attempt to describe the range of locomotor behavior patterns exhibited by zebrafish larvae. Using high-speed digital imaging, a variety of swimming and turning behaviors were analyzed in 6- to 9-day-old larval fish. Swimming episodes appeared to fall into two categories, with the point of maximal bending of the larva's body occurring either near the mid-body (burst swims) or closer to the tail (slow swims). Burst swims also involved larger-amplitude bending, faster speeds and greater yaw than slow swims. Turning behaviors clearly fell into two distinct categories: fast, large-angle escape turns characteristic of escape responses, and much slower routine turns lacking the large counterbend that often accompanies escape turns. Prey-capture behaviors were also recorded. They were made up of simpler locomotor components that appeared to be similar to routine turns and slow swims. The different behaviors observed were analyzed with regard to possible underlying neural control systems. Our analysis suggests the existence of discrete sets of controlling neurons and helps to explain the need for the roughly 200 spinal-projecting nerve cells in the brainstem of the larval zebrafish.

scholarly journals Suction Flows Generated by the Carnivorous Bladderwort Utricularia—Comparing Experiments with Mechanical and Mathematical Models

Fluids ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 33 ◽  
Author(s):  
Krizma Singh ◽  
Roberto C. Reyes ◽  
Gabriel Campa ◽  
Matthew D. Brown ◽  
Fatima Hidalgo ◽  
...  
Keyword(s):  
Solid Mechanics ◽  
Larval Fish ◽  
Fish Larvae ◽  
Experimental Studies ◽  
Axial Flow ◽  
Aquatic Organisms ◽  
Suction Feeding ◽  
Scaled Model ◽  
Feeding Mode ◽  
Biological Studies

Suction feeding is a well-understood feeding mode among macroscopic aquatic organisms. The little we know about small suction feeders from larval fish suggests that small suction feeders are not effective. Yet bladderworts, an aquatic carnivorous plant with microscopic underwater traps, have strong suction performances despite having the same mouth size as that of fish larvae. Previous experimental studies of bladderwort suction feeding have focused on the solid mechanics of the trap door’s opening mechanism rather than the mechanics of fluid flow. As flows are difficult to study in small suction feeders due to their small size and brief event durations, we combine flow visualization on bladderwort traps with measurements on a mechanical, dynamically scaled model of a suction feeder. We find that bladderwort traps generate flows that are more similar to the inertia-dominated flows of adult fish than the viscosity-dominated flows of larval fish. Our data further suggest that axial flow transects through suction flow fields, often used in biological studies to characterize suction flows, are less diagnostic of the relative contribution of inertia versus viscosity than transverse transects.

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