Many jellyfish are transparent, and they have seemingly simple movements and few visible interacting parts. They should, therefore, be easy to synthesize with man-made parts, but that's not what bioengineers discovered when they recently built a jellyfish mimic from rat heart cells attached to a silicone frame.

Rorqual whales, including blue whales and minke whales, don't have teeth. Instead, they eat tiny sea animals by filtering water with comb-like bristles in their giant mouths called "baleen." Working in symphony with an array of rorqual-specific traits, a newly discovered sensory organ builds an even stronger case for their special creation.