Britney Spears' husband Kevin Federline has added some ferocious new members to their growing family - a shiver of sharks living in a giant tank. The TOXIC singer, who is pregnant with the couple's second child after giving birth to son Sean Preston last year (05), is terrified of the white sharks which are growing bigger by the day. She says, "Kevin's sharks are the size of my arm. He feeds them tons of shrimp and they're getting bigger. "I'm scared. They're white sharks, but they're not Great Whites."