Physeteridae
Physeteridae is a family of cetaceans that contains a single extant species, the sperm whale (Physeter macrocephalus). These large, toothed whales are characterized by their distinctive head, which is disproportionately large and contains a massive oil-filled organ called the spermaceti organ. Physeteridae is a relatively young family in evolutionary terms, with the earliest fossils appearing in the Miocene epoch. They are found in all oceans, typically preferring deep water but occasionally visiting shallower waters.
Common Names
Physeteridae are commonly known as sperm whales. They are also sometimes called cachalots, which derives from the Portuguese word for sperm whale, cachalote.
Characteristics
Sperm whales are the largest toothed whales and one of the largest animals on Earth. They have a number of distinctive features, including:
- A massive, blocky head that comprises about one-third of its total body length.
- A spermaceti organ, a large, oil-filled structure located in the head that is used for echolocation and possibly for temperature regulation.
- A single blowhole located on the left side of the head.
- A long, narrow lower jaw with teeth only on the bottom jaw.
- A powerful tail flukes used for propulsion.
Environment
Sperm whales are found in all oceans, with a preference for deep water. They are often found in areas with deep ocean trenches, where they can dive to depths of over 3,000 meters (9,800 feet) in search of prey. They are also known to visit shallower waters, especially in areas with abundant food sources, such as squid.
References
World Wildlife Fund: Sperm Whale
National Geographic: Sperm Whales
MarineBio: Sperm Whale