L’Aquàrium de Barcelona

This guide to L'Aquàrium de Barcelona's shark tunnel is about the sand tiger sharks circling above the walkway, and the brutal biology each one survived before birth: dozens of embryos sharing two wombs, and a sibling rivalry scientists call embryophagy. You'll hear how the sole survivor in each womb keeps growing on a diet of unfertilized eggs before it is finally born. Look up as you ride the eighty-meter glass tunnel beneath four million liters of seawater.