Ziphius cavirostris

Cuvier's beaked whale or the goose-beaked whale (Ziphius cavirostris), the only member of the genus Ziphius, is the most widely distributed of all the beaked whales. It is one of the most frequently seen beaked whales, despite preferring deep pelagic waters, usually deeper than 1,000 m (3,300 ft). The species name comes from Greek xiphos, 'sword', and Latin cavus, 'hollow' and rostrum, 'beak', referring to the indentation on the head in front of the blowhole. The French anatomist Georges Cuvier, in his treatise Sur les Ossements fossiles (1823), first described the species based on an imperfect skull from the Mediterranean coast of France. It had been obtained by M. Raymond Gorsse in the department of Bouches-du-Rhône, near Fos, in 1804 from a local who had found it on the seashore the previous year. Cuvier named it Ziphius cavirostris, the specific name being derived from the Latin cavus for 'hollow' or 'concave', in reference to the deep hollow (the prenarial basin) in the skull, a diagnostic trait of the species. Cuvier believed it to represent the remains of an extinct species. Zoologists did not realize the extant nature of the species until 1850, when Paul Gervais compared the type specimen to another that had stranded itself at Aresquiès, Hérault, in May of the same year, and found the two to be identical. There is no connection between Cuvier's beaked whale and the mythical Ziphius, or 'Water-Owl', a creature in medieval folklore which had the characteristics of both an owl and a fish. Its dorsal fin was said to be sword-shaped, and pierced ship's hulls, while the beak was said to resemble an owl's head. The body of Cuvier's beaked whale is robust and cigar-shaped, similar to those of other beaked whales, and can be difficult to distinguish from many of the mesoplodont whales at sea. It grows to about 5–7 m (16–23 ft) in length and weighs 2,500 kg (5,500 lb). No significant size difference is seen between sexes. Its dorsal fin is curved, small, and located two-thirds of the body length behind the head. Its flippers are equally small and narrow and can be tucked into pockets in the body wall, presumably to prevent drag while swimming. Like other beaked whales, its flukes are large and lack the medial notch found in all other cetaceans. The head is short with a small, poorly defined rostrum and a gently sloping melon. A pair of throat grooves allows the whale to expand this region when sucking in its prey. Cuvier's beaked whale has a short beak in comparison with other species in its family, with a slightly bulbous melon, which is white or creamy in color, and a white strip runs back to the dorsal fin about two-thirds of the way along the back. The rest of the body color varies by individual: some are dark grey; others are a reddish brown. Individuals commonly have white scars and patches caused by cookiecutter sharks. The dorsal fin varies in shape from triangular to highly falcate, whilst the fluke is about one-quarter the body length. They live for around 40 years. Cuvier's beaked whales feed on several species of squid, including those in the families Cranchiidae, Onychoteuthidae, Brachioteuthidae, Enoploteuthidae, Octopoteuthidae, and Histioteuthidae; they also prey on deep-sea fish. In 2014, scientists reported that they had used satellite-linked tags to track Cuvier's beaked whales off the coast of California, and found the animals dived up to 2,992 m below the ocean surface and spent up to two hours and 17 minutes underwater before resurfacing, which represent both the deepest and the longest dives ever documented for any mammal. Cuvier's has a cosmopolitan distribution in deep, offshore waters from the tropics to the cool, temperate seas. In the North Pacific, it occurs as far north as the Aleutians and in the North Atlantic as far north as Atlantic Canada in the west to the Shetlands in the east. In the Southern Hemisphere, it occurs as far south as Tierra del Fuego, South Africa, southern Australia, New Zealand, and the Chatham Islands. It also frequents such inland bodies of waters as the Gulfs of Mexico and likely the Caribbean and Mediterranean Seas. Mediterranean population is genetically distinct from North Atlantic population(s).