Seahorse Shape Explained

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Seahorse shape explained, (theoretically, that is) claim scientists in Nature Communications DOI: doi:10.1038/ncomms1168 25 January 2011, and BBC Earth News 26 January 2011. Sam Van Wassenbergh from the University of Antwerp in Belgium and colleagues have used high speed photography and mathematical modelling to determine how far a seahorse can reach out to capture prey. Seahorses eat small crustaceans and other tiny animals that float in the water. When they rotate their heads upwards the curved shape of their body enables their mouth to move forward and capture prey from further away than if they were straight. Seahorses are believed to have evolved from pipefish, which have straight bodies and swim after their prey. Seahorses use their tails to anchor themselves to seagrass and wait for prey to come within striking distance. Wassenberg commented: "My theory is that you have this ancestral pipefish-like fish and they evolved a more cryptic lifestyle." This meant they needed to be able to reach further from one spot to capture prey, and so they evolved the S-shape to be able to use their bodies to increase their range of movement. The research team’s report is entitled “An adaptive explanation for the horse-like shape of seahorses” and they concluded: “The biomechanics of prey capture thus provides a putative selective advantage that may explain the bending of the trunk into a horse-like shape.”

BBC Earth

Editorial Comment: This study does explain why the S shape of a seahorse body enables it to collect distant food from further away than if it was straight, but it does not actually explain how a straight pipe fish could change into an S-shaped fish. Wassenberg’s theory that a pipe fish “evolved a more cryptic lifestyle” is not actually based on any evidence – only on Wassenberg’s imagination. Even if we insist that a pipefish could decide to take up a lifestyle of sitting upright in sea grass, this would not change its genes to make it into a seahorse shape. If we deal only with the scientific evidence we have on seahorses, then we must conclude they have always been S-shaped and have multiplied after their kind, as Genesis says God created them to do.

Evidence News 9 February 2011

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