The beautiful creatures are famously bad swimmers, but they have a secret weapon to sneak up on their prey. Their peculiar snouts are shaped to create very few ripples in the water, effectively cloaking them as they creep up and pounce on tiny crustaceans, reports BBC Science News referring to research published by Dr Brad Gemmell of the University of Texas.
An abstract summary of the report published by 'Nature Communications' in greater scientific detail explains that Syngnathid fish (seahorses, pipefish and sea dragons) are slow swimmers yet capture evasive prey (copepods) using a technique known as the ‘pivot’ feeding, which involves rapid movement to overcome prey escape capabilities. However, this feeding mode functions only at short range and requires approaching very closely to hydrodynamically sensitive prey without triggering an escape.
Researchers used holographic and particle image velocimetry (PIV) to show that head morphology functions to create a reduced fluid deformation zone, minimizing hydrodynamic disturbance where feeding strikes occur (above the end of the snout), and permits syngnathid fish to approach highly sensitive copepod prey (Acartia tonsa) undetected.
Sources: 1. BBC 2.Nature Communications (http://www.nature.com/ncomms/2013/131126/ncomms3840/full/ncomms3840.html)