By Vidya Rajan, Columnist, The Times Recently I came across this quiz clue: What links barreleye fish, ghost shrimp, glass frogs, golden tortoise beetles, jellyfish and sea angels?[1] Besides the obvious fact that they are all animals, there were a few options I considered: 1. They are aquatic (but the beetles are not); 2. They are invertebrates (but frogs are not) and 3. They are transparent (and...