The Princess and the Shark. If I ever write a children's book, that's what it will be titled. If, that is, I don't care about quality but do care about selling a lot of books. Based on the very small, unreliable sample size of 2 school libraries that I've worked in, both on the Upper West Side of Manhattan, girls in grades K-2 want books about princesses and their male peers want to read about sharks.
There are other scary, fierce, awesome-looking animals besides sharks. Why the obsession? I have no idea.
And the princesses. When these girls ask for princess books they mean Disney. I offer them Shirley Climo's The Egyptian Cinderella and they turn up their noses.
Of course there are other requested topics. Ballet, gymnastics, soccer, and lately, cooking. The boys also ask for books about the military - soldiers, military aircraft, the navy. Crafts, especially origami, are big too.
The gender divide is (nearly?) absolute. To date, I have never had a boy request a princess book or a girl request a book about the military. I probably have had boys ask for cooking and have definitely had them ask for origami, and I've probably had girls ask for sharks.
So in order to capture the market and straddle that divide, The Princess and the Shark it is!