Hydrodynamics of prey capture in sharks: effects of substrate

Sandra Nauwelaerts*, Cheryl Wilga, Christopher Sanford, George Lauder

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

42 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)341-345
Number of pages5
JournalJournal of the Royal Society Interface
Volume4
Issue number13
DOIs
Publication statusPublished - 22-Apr-2007

Keywords

  • hydrodynamics
  • feeding
  • shark
  • digital particle velocimetry
  • modelling
  • BLUEGILL SUNFISH
  • SUCTION
  • FLOW
  • FISH

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