Common minke whale to 20 growth layers in their tympanic bullae, which may correspond to about 15 to 20 years of age. Both sexes can live to about 50 years of age – the oldest in a study of Icelandic minke whales were 42 years for females and 47 years for males, respectively. Common minke whales have been described as ichthyophagous, but their diet also includes pelagic crustaceans and cephalopods and varies by region, season, and year. In the North Atlantic, they primarily eat small schooling fish, demersal fish, and krill. A 2007 study showed that off Spitsbergen they fed almost exclusively on
Creature type (Dungeons & Dragons) all animal type monsters are based on real world animals. Creature entries based on mythological, fictional, or nonexistent animals are usually classified as magical beasts (see below). Besides ordinary fish, birds, reptiles and mammals, the animal type is also applied to depictions of dinosaurs, prehistoric animals, and "dire" or specially modified, often larger and scarier, versions of real world animals. Some real world animals are not given the animal type in the game. Examples include arthropods (insects, spiders, etc.) and worms, which the game classifies as "vermin" (see below) and not animals. Mollusks, such as octopuses, are often classified as