Class Mammalia, Order Cetacea
Classification There are two basic kinds of whales: toothed whales (suborder Odontoceti) and baleen whales (suborder Mysticeti). There are five basic kinds of toothed whales: dolphins (family Delphinidae) and porpoises (family Phocoenidae), river dolphins (superfamilies Inioidea, Lipotoidea, Platanistoidea), narwhals and belugas (family Monodontidae), beaked whales (superfamily Ziphioidea), and sperm whales (superfamily Physeteroidea). There are three basic kinds of baleen whales: gray whales and the rorquals (superfamily Balaenopteroidea), bowhead and right whales (family Balaenidae), and pygmy right whales (family Neobalaenidae). Blowholes Baleen whales have two blowholes while toothed whales have only one (evolutionarily one became more dominant than the other). Baleen Feeding There are two basic kinds of baleen feeding tactics: skimming (swimming with the mouth open, continuously filtering) exhibited by right, bowhead, and gray whales (gray whales skim the ocean floor), or lunging (diving at masses of fish with the mouth wide open) exhibited by rorquals. Reproduction Dispite the name, the sperm whale doesn't have the largest testicles, the right whale does (the largest of any organism). The blue whale has the largest penis. Important Notes While whales are mammals, not all mammals are whales. Have you ever looked at a picture of a whale and wondered, "what the heck is that?"? If so, it was probably a right whale.