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

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.

1983 ◽  
Vol 104 (1) ◽  
pp. 1-13 ◽  
Author(s):  
GEORGE V. LAUDER

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.


1997 ◽  
Vol 200 (8) ◽  
pp. 1255-1269 ◽  
Author(s):  
L Ferry-Graham

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.


Author(s):  
Eoin Cunniffe ◽  
Mark Connor ◽  
Marco Beato ◽  
Adam Grainger ◽  
Walter McConnell ◽  
...  

The aims of this investigation were to describe the physical output of hockey relative to possession status, and to identify differences in physical output during each possession category with respect of match result. Ten international matches were analysed utilizing Sportscode to identify in and not in possession instances. 24 players (age 26 ± 4) wore a 10 Hz GPS device to track physical output. Linear Mixed Models and post hoc pairwise comparisons were utilised to compare the physical output in each possession category within each position and relative to match result. Significant main effects were found for possession status on several physical output metrics (p ≤ 0.05). For all positions except forwards, not in possession instances were more physically demanding than in possession instances for metrics such as relative total distance, explosive distance, and high-speed running (>5.5 m.s−1). No significant difference was identified between possession category physical output aligned with match result (p > 0.05). This study shows for the first time that not in possession instances were more physically demanding than in possession instances for defenders, outside backs and midfielders. For not in possession instances, relative total distance and high-speed running was, on average, 13% and 41% higher compared to in possession instances. Furthermore, there was no statistical difference in physical output for any position during each possession category relative to the match result.


1996 ◽  
Vol 199 (9) ◽  
pp. 1961-1971
Author(s):  
A Cook

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.


2021 ◽  
Vol 2 ◽  
Author(s):  
Clara Isabel Anton y Otero ◽  
Enrico Di Bella ◽  
Ivo Krejci ◽  
Tissiana Bortolotto

This study aimed to compare marginal adaptation in enamel and dentin before and after aging of laser vs. bur-prepared mixed class V cavities restored by different restorative systems. Seventy two caries-free human molars were distributed to nine experimental groups; cavities were prepared using two different lasers: a handpiece -integrated 2.94 μm Er:YAG laser at 4.5 W, 300 mJ, and 0.75 W, 50 mJ with 15 Hz (LiteTouch, Light Instruments, Israel) and a novel CO2 laser at 12.95 W, 19.3 mJ, and 4.1 W, 6.11 mJ with 671 Hz (Solea 9.3 μm, Convergent Dental, USA). Cavities prepared with conventional diamond burs (Intensiv, Switzerland) in a red contra angle at high speed under maximal water cooling served as control. Cavities were prepared under simulation of dentinal fluid and restored using three different self-etching universal adhesives in combination with three nanohybrid composites, applied in two layers: Scotchbond Universal with Filtek Supreme XTE (3M, USA), G-Premio BOND with Essentia Universal (GC, Japan), and OptiBond Universal with Harmonize Universal (Kerr, USA). After restorations' polishing and simultaneous thermal (5–50°C, 2 min each) and mechanical loading (max. 49 N; 200,000 cycles), replicas of restoration margins were examined under SEM at × 200 magnification. Percentages of continuous margins (CMs) were quantified before and after the fatigue test and statistically compared (two-way ANOVA with Fisher's least significant difference [LSD] post hoc test). Significant differences were found in almost all groups between the results before and after the fatigue test, as well as between the different preparation tools and restorative materials (p < 0.05). Traditional bur preparations are confirmed as gold standard in enamel and dentin, as all three tested restorative systems provide results of marginal adaptation of more than 80% CM after loading. Er:YAG laser preparations can be equally effective in combination with SBU/Filtek Supreme XTE. CO2 laser ablation could not provide convincing results with the tested self-etching restorative systems. Marginal adaptation has been highly dependent on the substrate and showed impaired adhesion, especially in enamel. Scotchbond Universal/Filtek Supreme XTE showed the highest and most stable values of CM. The other two restorative systems were highly dependent on the preparation device of the substrate.


Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 178
Author(s):  
Pawel Gierasimiuk ◽  
Marta Wasilewska ◽  
Wladyslaw Gardziejczyk

The paper presents a comparison of the skid resistance of concrete pavements textured with different techniques in the process of simulating phenomena occurring in actual road conditions. Tests were carried out on five different texturing methods for concrete pavements: burlap drag (BuD), brush drag (BrD), transverse tining (TT), longitudinal tining (LT) and exposed aggregate concrete (EAC). Changes in the skid resistance were recorded by measurements with a British pendulum tester and a circular texture meter before and during the simulation of the abrasion (1st phase of test) and polishing (2nd phase of test) of specimens using a slab polisher. The results of BPN (British pendulum number) and MPD (mean profile depth) allowed us to determine the influence of microtexture and macrotexture on skid resistance. Analysis of variance showed that the method of texturing concrete pavements has a significant influence on the mean BPN values as well as the MPD parameter at each stage of the test. In order to distinguish homogeneous groups in terms of BPN and MPD levels at the particular stages of the process, the Tukey’s HSD (honest significant difference) post-hoc test was performed. It was found that EAC obtained the most favorable results of all the tested pavement types. Due to the high value of the MPD coefficient after the test and the appropriate values of the friction coefficient, it was confirmed that the EAC pavement will be a durable solution due to the guarantee of skid resistance on high-speed roads during its service life.


1998 ◽  
Vol 201 (16) ◽  
pp. 2433-2444 ◽  
Author(s):  
LA Ferry-Graham

Recent work on teleosts suggests that attack behaviors or kinematics may be modified by a predator on the basis of the size of the prey or the ability of the prey to sense predators and escape capture (elusivity). Sharks are generally presumed to be highly visual predators; thus, it is reasonable to expect that they might also be capable of such behavioral modulation. In this study, I investigated the effect of prey item size and type on prey-capture behavior in leopard sharks (Triakis semifasciata) that had been acclimated to feeding in the laboratory. Using high-speed video, sharks were filmed feeding on two sizes of the same prey item (thawed shrimp pieces) and two potentially more elusive prey items (live earthworms and live mud shrimp). In leopard sharks, little effect of prey elusivity was found for kinematic variables during prey capture. However, the large proportion of successful captures of the live prey suggests that they did not prove to be truly elusive prey items for the leopard shark. There were significant size effects on prey-capture kinematics, with the larger non-elusive items inducing greater head expansion during prey capture. Ram-suction index values also indicated that strikes on large, non-elusive prey had a significantly larger suction component than strikes on similar small prey items. This finding is interesting given that the two sizes of non-elusive prey item offered no differential challenge in terms of a performance consequence (reduced capture success).


1995 ◽  
Vol 198 (3) ◽  
pp. 709-720 ◽  
Author(s):  
G Gillis ◽  
G Lauder

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.


Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1928
Author(s):  
Naeemah Noordien ◽  
Suné Mulder-van Staden ◽  
Riaan Mulder

Oral health care workers (OHCW) are exposed to pathogenic microorganisms during dental aerosol-generating procedures. Technologies aimed at the reduction of aerosol, droplets and splatter are essential. This in vivo study assessed aerosol, droplet and splatter contamination in a simulated clinical scenario. The coolant of the high-speed air turbine was colored with red concentrate. The red aerosol, droplets and splatter contamination on the wrists of the OHCW and chests of the OHCW/volunteer protective gowns, were assessed and quantified in cm2. The efficacy of various evacuation strategies was assessed: low-volume saliva ejector (LV) alone, high-volume evacuator (HV) plus LV and an extra-oral dental aerosol suction device (DASD) plus LV. The Kruskal–Wallis rank-sum test for multiple independent samples with a post-hoc test was used. No significant difference between the LV alone compared to the HV plus LV was demonstrated (p = 0.372059). The DASD combined with LV resulted in a 62% reduction of contamination of the OHCW. The HV plus LV reduced contamination by 53% compared to LV alone (p = 0.019945). The DASD demonstrated a 50% reduction in the contamination of the OHCWs wrists and a 30% reduction in chest contamination compared to HV plus LV. The DASD in conjunction with LV was more effective in reducing aerosol, droplets and splatter than HV plus LV.


2017 ◽  
Vol 21 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Athanasios Synarellis ◽  
Pantelis Kouros ◽  
Elisabeth Koulaouzidou ◽  
Dimitrios Strakas ◽  
Eugenia Koliniotou-Koumpia

SummaryBackground: The aim of this in vitro study was to compare the degree of microleakage on enamel and dentin margins of class V cavities prepared with either a high-speed drill or an Er,Cr:YSGG laser (2780 nm) and to associate their use with a beveling method for the margin.Method and Materials: Sixty bovine incisors were randomly distributed into three groups. Group 1 (G1) cavities were laser prepared and bur beveled, group 2 (G2) cavities were bur prepared and beveled, while cavities of group 3 (G3) were laser prepared and beveled. Cavities were restored with selective enamel etching, using the same bonding agent and nano-hybrid resin composite for all groups. After thermocycling, microleakage was assessed using a methylene blue dye penetration method.Results: Statistical analysis (Mann-Whitney, Kruskal-Wallis and post-hoc Dunn’s multiple comparison tests) demonstrated significantly higher microleakage for dentin compared to enamel margins in G1. Enamel margin microleakage was found to be significantly higher at G3 compared to G1 (p=0.032) and G2 (p=0.001), while no significant differences were found between G1 and G2 (p=0.850). Regarding dentin margins, G2 group performed significantly better than G1 and G3 (p<<0.001), while there was no significant difference among G1 and G3 scores (p=1.000).Conclusions: The conventional cavity preparation method seems to perform better in terms of microleakage than the Er,Cr;YSGG laser. Laser-prepared cavities could perform better in terms of microleakage if an additional step of enamel bur-beveling is performed prior to restoration.


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