Add Yahoo as a preferred source to see more of our stories on Google. Goose-beaked whales (Ziphius cavirostris) hold the record for deepest dive of any marine mammal, and researchers hope that ...

Pygmy sperm whales (Kogia breviceps) are among the ocean's most enigmatic inhabitants—rarely seen and largely unstudied. They live far offshore in small groups, diving in search of squid and fish.