In the Blink of an Eye

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Science  14 Aug 2009:
Vol. 325, Issue 5942, pp. 794
DOI: 10.1126/science.325_794b

Ambush of a dinoflagellate by Oithona davisae.

CREDIT: KIØRBOE ET AL., PROC. NATL. ACAD. SCI. U.S.A. 106, 12394 (2009)

The advent of high-speed video microscopy is helping to resolve many of the hitherto unseen mysteries of animal biomechanics. Copepods—crustaceans that typically are smaller than 1 mm and are a vital component of marine foodwebs—feed on even smaller prey that they capture in swift, surprise lunges. What has been a puzzle is how this is achieved without alerting the target or displacing it by fluid flow caused by the leaping copepod. Capturing 2000 images per second, Kiørboe et al. show that the attack is so fast (about 100 mm s−1) that the viscous boundary layer ahead of the predator remains thin, thus preserving the element of surprise, as well as maneuverability. In terms of evolutionary feasibility, this strategy appears to be restricted to zooplankton in a limited size range (0.3 to 1 mm), which also possess a powerful musculature.

Proc. Natl. Acad. Sci. U.S.A. 106, 12394 (2009).

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