What is "beaked whale"

Beaked \Beaked\ (b[=e]kt), a.

1. Having a beak or a beaklike point; beak-shaped. ``Each beaked promontory.''
   --Milton.

2. (Biol.) Furnished with a process or a mouth like a beak; rostrate.

   Beaked whale (Zo["o]l.), a cetacean of the genus Hyperoodon; the bottlehead whale.

n. Any of at least 20 species of whales in the family Ziphiidae, known to dive to great depths.

n. any of several whales inhabiting all oceans and having beaklike jaws with vestigial teeth in the upper jaw

Beaked whales are the members of the family Ziphiidae, which consists of 22 species. These toothed whales are notable for their elongated beaks. Among air-breathing animals, beaked whales are some of the most extreme divers: Cuvier's beaked whales regularly dive for an hour at a depth over , and the longest and deepest foraging dive recorded is 137.5 minutes at . This is the greatest dive-depth known for a mammal.

Beaked whales are one of the least known groups of mammals because of their deep-sea habitat, mysterious habits, and apparent low abundance. Only three to four of the 22 species are reasonably well-known. Baird's and Cuvier's beaked whales were subject to commercial exploitation, off the coast of Japan, while the northern bottlenose whale was extensively hunted in the northern part of the North Atlantic late in the 19th and early 20th centuries.