Integration between swim speed and mouth size evolves repeatedly in Trinidadian guppies and aligns with suction-feeding fishes

2019 ◽  
Vol 222 (2) ◽  
pp. jeb190165 ◽  
Author(s):  
Emily A. Kane ◽  
Megan M. Roeder ◽  
McKenna L. DeRue ◽  
Cameron K. Ghalambor
Keyword(s):  
Suction Feeding ◽  
Mouth Size

scholarly journals The benefits of planar circular mouths on suction feeding performance

2012 ◽  
Vol 9 (73) ◽  
pp. 1767-1773 ◽  
Author(s):  
Tyler Skorczewski ◽  
Angela Cheer ◽  
Peter C. Wainwright
Keyword(s):  
Prey Capture ◽  
Peak Flow ◽  
Mouth Opening ◽  
Suction Feeding ◽  
Flow Rates ◽  
Computational Fluid Dynamics Simulations ◽  
Enhance Efficiency ◽  
And Performance ◽  
Dynamics Simulations ◽  
Hydrodynamic Effects

Suction feeding is the most common form of prey capture across aquatic feeding vertebrates and many adaptations that enhance efficiency and performance are expected. Many suction feeders have mechanisms that allow the mouth to form a planar and near-circular opening that is believed to have beneficial hydrodynamic effects. We explore the effects of the flattened and circular mouth opening through computational fluid dynamics simulations that allow comparisons with other mouth profiles. Compared to mouths with lateral notches, we find that the planar mouth opening results in higher flow rates into the mouth and a region of highest flow that is positioned at the centre of the mouth aperture. Planar mouths provide not only for better total fluid flow rates through the mouth but also through the centre of the mouth near where suction feeders position their prey. Circular mouths are shown to provide the quickest capture times for spherical and elliptical prey because they expose the prey item to a large region of high flow. Planar and circular mouths result in higher flow velocities with peak flow located at the centre of the mouth opening and they maximize the capacity of the suction feeders to exert hydrodynamic forces on the prey.

scholarly journals More than Meets the Eye: Functionally Salient Changes in Internal Bone Architecture Accompany Divergence in Cichlid Feeding Mode

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
R. Craig Albertson ◽  
W. James Cooper ◽  
Kenneth A. Mann
Keyword(s):  
Genetic Basis ◽  
Dominant Mode ◽  
Bone Architecture ◽  
Foraging Strategies ◽  
Craniofacial Skeleton ◽  
Suction Feeding ◽  
Foraging Mode ◽  
Feeding Mode ◽  
Adaptive Radiations ◽  
African Cichlids

African cichlids have undergone extensive and repeated adaptive radiations in foraging habitat. While the external morphology of the cichlid craniofacial skeleton has been studied extensively, biomechanically relevant changes to internal bone architecture have been largely overlooked. Here we explore two fundamental questions: (1) Do changes in the internal architecture of bone accompany shifts in foraging mode? (2) What is the genetic basis for this trait? We focus on the maxilla, which is an integral part of the feeding apparatus and an element that should be subjected to significant bending forces during biting. Analyses of μCT scans revealed clear differences between the maxilla of two species that employ alternative foraging strategies (i.e., biting versus suction feeding). Hybrids between the two species exhibit maxillary geometries that closely resemble those of the suction feeding species, consistent with a dominant mode of inheritance. This was supported by the results of a genetic mapping experiment, where suction feeding alleles were dominant to biting alleles at two loci that affect bone architecture. Overall, these data suggest that the internal structure of the cichlid maxilla has a tractable genetic basis and that discrete shifts in this trait have accompanied the evolution of alternate feeding modes.

An Integral Heat Sink for Cooling Microelectronic Components

1993 ◽  
Vol 115 (3) ◽  
pp. 284-291 ◽  
Author(s):  
S. H. Bhavnani ◽  
C.-P. Tsai ◽  
R. C. Jaeger ◽  
D. L. Eison
Keyword(s):  
Heat Sink ◽  
Silicon Surface ◽  
Numerical Study ◽  
High Heat ◽  
Heat Fluxes ◽  
Silicon Surfaces ◽  
Source Surface ◽  
Mouth Size ◽  
Severe Constraint ◽  
Boiling Incipience

Liquid immersion cooling is rapidly becoming the mechanism of choice for the newest generation of supercomputers. Miniaturization at both the chip and module level places a severe constraint on the size of the heat sink employed to dissipate the high heat fluxes generated. A study was conducted to develop a surface that could augment boiling heat transfer from silicon surfaces under these constraints. The surface created consists of reversed pyramidal features etched directly on to the silicon surface. Experiments were conducted in a saturated pool of refrigerant-113 at atmospheric pressure. The inexpensive crystallographic etching techniques used to create the enhanced features are described in the paper. The main characteristics of interest in the present study were the incipient boiling superheat and the magnitude of the temperature overshoot at boiling incipience. Results were obtained for test sections with various cavity densities, and compared with data for the smooth untreated surface. It was found that incipient boiling superheat was reduced from a range of 27.0–53.0° C for the untreated silicon surface, to a range of 2.5–15.0° C for the enhanced surfaces. The overshoot also decreased considerably; from about 12.0–18.0° C for two classes of untreated surfaces, to a range of 1.5–5.3° C for the enhanced surfaces. The values of the incipient boiling superheat, and those of the overshoot decreased with a decrease in cavity mouth size. Two ratios of heat source surface area to the area of the enhanced surface were studied. The overshoot values obtained for these surfaces were compared with those observed for some commonly used enhanced surfaces. An elementary numerical study was conducted to estimate the magnitude of heat spreading.

Evaluating the use of ram and suction during prey capture by cichlid fishes

2001 ◽  
Vol 204 (17) ◽  
pp. 3039-3051 ◽  
Author(s):  
Peter C. Wainwright ◽  
Lara A. Ferry-Graham ◽  
Thomas B. Waltzek ◽  
Andrew M. Carroll ◽  
C. Darrin Hulsey ◽  
...  
Keyword(s):  
Poecilia Reticulata ◽  
Prey Capture ◽  
Suction Feeding ◽  
Predator Species ◽  
Cichlid Fishes ◽  
Major Constraint ◽  
Exponential Decline ◽  
Astronotus Ocellatus ◽  
Limited Variation ◽  
Jaw Protrusion

SUMMARYWe characterized prey-capture strategies in seven species of cichlid fishes representing diverse trophic habits and anticipated feeding abilities. The species examined were Petenia splendida, Cichla ocellaris, Cichlasoma minckleyi, Astronotus ocellatus, Crenicichla geayi, Heros severus (formerly Cichlasoma severum) and Cyprichromis leptosoma. Three individuals per species were filmed with video at 500Hz as they captured live adult Artemia sp. and Poecilia reticulata. For each feeding sequence, we measured the contribution of predator movement towards the prey (i.e. ram) and the movement of prey towards the predator due to suction. The use of ram differed significantly among prey types and predator species, varying as much as sixfold across predator species. High values of ram resulted in high attack velocities. Jaw protrusion contributed as much as 50% to overall ram values in some species, verifying its role in enhancing attack velocity. Suction distance did not vary significantly among species. Diversity in prey-capture behavior was therefore found to reflect differences among species in the strategy used to approach prey. Limited variation in the distance from which prey were sucked into the mouth is interpreted as the result of an expected exponential decline in water velocity with distance from the mouth of the suction-feeding predator. We propose that this relationship represents a major constraint on the distance over which suction feeding is effective for all aquatic-feeding predators.

Sex Differences in Feeding Behaviour at Feeding Station Scale in Soay Sheep (Ovis Aries)

Behaviour ◽  
2004 ◽  
Vol 141 (8) ◽  
pp. 999-1020 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
Feeding Behaviour ◽  
Ovis Aries ◽  
Intake Rate ◽  
Same Sex ◽  
Soay Sheep ◽  
Food Items ◽  
Feeding Station ◽  
Foraging Decisions ◽  
Mouth Size ◽  
Mechanistic Response

AbstractHerbivorous ungulates live in a spatially heterogeneous environment making foraging decisions at a range of hierarchical scales, from bite size to landscape. We investigated the factors that control intake rate in Soay sheep (Ovis aries) when discrete items of food were sparsely distributed at the feeding station scale. Within the feeding station we varied the difficulty of accessing food, distance between items of food, difficulty of finding the food and complexity of the feeding station and recorded how intake rate responded in relation to body size, mouth size and the sex of the animal. Our findings demonstrated how increasing difficulty of accessing food, and increasing complexity of the feeding station negatively affected intake rate. The expected mechanistic response that smaller animals or animals with smaller mouth size were better at handling discrete small items of food, was overridden by individual and sexual differences in behaviour. We also considered that intake rate within a feeding station could be maximised by optimising the spatial pattern of offtake, and the results clearly indicated that both sexes tended to show clustered patterns of offtake. Animals of the same sex responded in a similar way to the difficulty in handling food items; males persevered more than females and consequently were less handicaped by having larger mouths. We discussed these results in relation to behavioural and body mass differences between the sexes and animals.

scholarly journals Hydrodynamic modelling of aquatic suction performance and intra-oral pressures: limitations for comparative studies

2006 ◽  
Vol 3 (9) ◽  
pp. 507-514 ◽  
Author(s):  
Sam Van Wassenbergh ◽  
Peter Aerts ◽  
Anthony Herrel
Keyword(s):  
Hydrodynamic Force ◽  
Ambient Pressure ◽  
Simple Relationship ◽  
Suction Feeding ◽  
Aquatic Animals ◽  
Future Studies ◽  
Pharyngeal Cavity ◽  
Oral Pressure ◽  
Direct Indication ◽  
Suction Performance

The magnitude of sub-ambient pressure inside the bucco-pharyngeal cavity of aquatic animals is generally considered a valuable metric of suction feeding performance. However, these pressures do not provide a direct indication of the effect of the suction act on the movement of the prey item. Especially when comparing suction performance of animals with differences in the shape of the expanding bucco-pharyngeal cavity, the link between speed of expansion, water velocity, force exerted on the prey and intra-oral pressure remains obscure. By using mathematical models of the heads of catfishes, a morphologically diverse group of aquatic suction feeders, these relationships were tested. The kinematics of these models were fine-tuned to transport a given prey towards the mouth in the same way. Next, the calculated pressures inside these models were compared. The results show that no simple relationship exists between the amount of generated sub-ambient pressure and the force exerted on the prey during suction feeding, unless animals of the same species are compared. Therefore, for evaluating suction performance in aquatic animals in future studies, the focus should be on the flow velocities in front of the mouth, for which a direct relationship exists with the hydrodynamic force exerted on prey.

scholarly journals Patterns of Phenotypic Variation in the Mouth Size of Lanternfishes (Teleostei: Myctophiformes)

Copeia ◽  
2016 ◽  
Vol 104 (4) ◽  
pp. 795-807 ◽  
Author(s):  
Rene P. Martin ◽  
Matthew P. Davis
Keyword(s):  
Phenotypic Variation ◽  
Mouth Size

5. How amphibians feed

2021 ◽  
pp. 82-89
Author(s):  
T. S. Kemp
Keyword(s):  
Suction Feeding ◽  
Alternative Method

‘How amphibians feed’ studies how amphibians feed. Adult amphibians are all carnivores, mostly eating invertebrates. The most effective way for an amphibian to feed when it is under water is to get as close to its prey as possible, then open its mouth suddenly and widely to suck the food in with a stream of water. However, this kind of suction feeding is no use on land. Amphibians feeding on land must use an alternative method. The most common is to have a sticky tongue that can be protruded from the mouth to capture the prey. Another alternative method is to have strong jaws that can grasp the prey directly.

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