Skeletal kinematics of the hyoid arch in the suction-feeding shark Chiloscyllium plagiosum

In suction feeding, a volume of water is drawn into the mouth of a predator. Previous studies of suction feeding in fishes have shown that significant fluid velocities are confined to a region within one mouth width from the mouth. Therefore, the predator must be relatively close to the prey to ensure capture success. Here, theoretical modelling is combined with empirical data to unravel the mechanism behind feeding on a substrate. First, we approached the problem theoretically by combining the stream functions of two sinks. Computational fluid dynamics modelling is then applied to make quantitative predictions regarding the effects of substrate proximity on the feeding hydrodynamics of a benthic shark. An oblique circular cylinder and a shark head model were used. To test the models, we used digital particle image velocimetry to record fluid flow around the mouth of white-spotted bamboo sharks, Chiloscyllium plagiosum , during suction feeding on the substrate and in the water column. Empirical results confirmed the modelling predictions: the length of the flow field can be doubled due to passive substrate effects during prey capture. Feeding near a substrate extends the distance over which suction is effective and a predator strike can be effective further from the prey.

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Relative importance of growth and behaviour to elasmobranch suction-feeding performance over early ontogeny

Journal of The Royal Society Interface ◽

10.1098/rsif.2007.1189 ◽

2007 ◽

Vol 5 (23) ◽

pp. 641-652 ◽

Cited By ~ 15

Author(s):

Dayv Lowry ◽

Philip J Motta

Keyword(s):

Prey Capture ◽

Volume Growth ◽

Early Ontogeny ◽

Maximum Pressure ◽

Suction Feeding ◽

Size Dependent ◽

Chiloscyllium Plagiosum ◽

Dietary Shifts ◽

Triakis Semifasciata ◽

Leopard Sharks

Development of the ability to capture prey is crucial to predator survival. Trends in food-capture performance over early ontogeny were quantified for leopard sharks Triakis semifasciata and whitespotted bamboosharks Chiloscyllium plagiosum by measuring suction pressure and flow in front of the mouth during feeding. At any size, C. plagiosum produce greater subambient pressure and ingest more rounded water parcels. Maximum subambient pressure scaled with negative allometry in T. semifasciata and was accompanied by an increase in the time to reach maximum gape. Despite a similar trend in buccal expansion timing, maximum pressure in C. plagiosum scaled with isometry and was accompanied by an earlier onset of hyoid depression and a positive allometric increase in buccal reserve volume. Growth was the primary factor responsible for developmental trends in both species, with size-independent behavioural changes contributing little to overall performance variability. Ontogenetic dietary shifts are predicted for both species as a consequence of size-dependent changes in performance. Chiloscyllium plagiosum becomes anatomically and behaviourally canalized towards suction feeding, limiting the effective range of prey capture and possibly necessitating stalking. Triakis semifasciata , by contrast, retains the flexibility to employ both ram and suction and therefore captures more elusive prey with age.

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Chiloscyllium plagiosum: Kyne, P.M. & Burgess, G.H.

IUCN Red List of Threatened Species ◽

10.2305/iucn.uk.2006.rlts.t60222a12325334.en ◽

2006 ◽

Author(s):

Keyword(s):

Chiloscyllium Plagiosum

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Molecular cloning and expression analysis of major histocompatibility complex class IIB gene of the Whitespotted bambooshark (Chiloscyllium plagiosum)

Fish Physiology and Biochemistry ◽

10.1007/s10695-012-9685-2 ◽

2012 ◽

Vol 39 (2) ◽

pp. 131-142 ◽

Cited By ~ 6

Author(s):

Qian Ma ◽

Yong-Quan Su ◽

Jun Wang ◽

Zhi-Meng Zhuang ◽

Qi-Sheng Tang

Keyword(s):

Major Histocompatibility Complex ◽

Major Histocompatibility Complex Class ◽

Molecular Cloning ◽

Expression Analysis ◽

Cloning And Expression ◽

Complex Class ◽

Major Histocompatibility ◽

Chiloscyllium Plagiosum ◽

Histocompatibility Complex ◽

Class Iib

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The benefits of planar circular mouths on suction feeding performance

Journal of The Royal Society Interface ◽

10.1098/rsif.2011.0904 ◽

2012 ◽

Vol 9 (73) ◽

pp. 1767-1773 ◽

Cited By ~ 14

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.

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

International Journal of Evolutionary Biology ◽

10.1155/2012/538146 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 3

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.

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