Stealth predator

It's no secret that ctenophores, or comb jellies, are voracious predators on zooplankton.  They can make a serious dent in copepod densities, even though calanoid copepods aren't the easiest prey for most slow-moving predators.  This is because the copeods are highly attuned to the slighest motions of the water around them.  Ctenophores, however, have one-upped their crustacean prey.  The ctenophore Mnemiopsis uses tiny cilia within the oral lobes to produce a current of water that moves copepod prey very delicately into their gastrovascular cavity, before the copepods are aware that they're being consumed.  Here it is at PNAS.