Marine mammals are animals that spend the majority of their lives in or near the sea. Animals like dolphins, whales, seals, manatees, sea otters and even polar bears are considered marine mammals. Whales, dolphins, and porpoises all belong to the same taxonomic order called cetaceans. Cetaceans are truly remarkable animals ! They are mammals which means they are warmblooded, they have at least a few hairs on their bodies, and they nourish their young with milk. Cetaceans spend their whole lives in water and some live in family groups called “pods”. Whales, dolphins and porpoises must breathe air just like humans. However since cetaceans live in water, breathing is a little more difficult for them than it is for us. Most whales can hold their breath for prolonged periods of time. To take a breath whales must swim to the surface and exhale through their blowhole.This action has been dubbed spouting, but is also called blowing. When a whale head sticks its head straight up out of the water this behavior is called spyhopping. Whales use their strong flukes to propel their heads out the water so that the animal can look at his/her surroundings.
Over 70 species of whales, dolphins and porpoises populate the world’s oceans. To study these cetaceans we categorize the species into two main groups: baleen whales (or, mysticetes) and toothed whales (or, odontocetes).
Baleen whales are very large, have paired blow holes, and characteristic baleen plates that they use to filter food.
Toothed whales have (surprise) 1 to 65 teeth depending on the species and tend to be smaller than baleen whales. Toothed whales have a single blowhole and do not have baleen plates.
In the Mediterranean Sea there are 8 usual and 4 occasional cetacean species (this means that they enter the Mediterranean Sea through Gibraltar).