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- 12 enero, 2022 a las 8:34 am #35122madiedandridge4Invitado
<br><br>White-winged porpoise, or Dall’s porpoise (Latin Phocoenoides dalli) – the only species of the genus Phocoenoides family of porpoises. The specific name is given in honor of the American naturalist William Hiley Dall (1845-1927).<br>Appearance and other features<br>Males are 1.7-2 m long, females 1.7-1.8 m, average weight 100-220 kg, newborn 1 m and ≈11 kg. The back and sides are black, on the sides there is a large white spot from the to the level of the dorsal fin or a little further, a white border on the dorsal fin and tail lobes, the dorsal fin is triangular, slightly sickle-shaped, in adult males oblique forward. Males have a pronounced hump in front of the tail. There are two known color morphs of this species: described above dalli-type and in which the white spot on the sides extends more forward – to the level of the pectoral fins. In addition, there are transitional stages between these morphs, there are also completely black animals and other color options. In some sources, these are not just color morphs, but different species: the white-winged porpoise (Phocoenoides dalli) and southern white-winged porpoise (Phocoenoides truei).<br><br>Compared to the bottlenose dolphin, the white-winged porpoise has twice the blood-to-body mass ratio, three times the concentration of red blood cells and 1.4 times the relative heart mass, since it can swim faster than the bottlenose dolphin and can dive deeper.<br>Distribution and populations<br>They keep both near the coast and in the open sea. A common species in the Far Eastern waters, distributed from the Japanese to the Okhotsk, Bering and Chukchi Seas, found off the coast of Sakhalin Island, the Kuril and Commander Islands, Kamchatka and Chukotka. Dalli-type is ubiquitous, truei-type is found in the waters of Primorye and the southern Kuril Islands. Previously, these forms were considered different races or subspecies, but recent studies have shown that these are color morphs, the proportion of which varies in different populations. Known hybrids between whitefly and common (Phocoena phocoena) porpoises.<br>Lifestyle and behavior<br>They usually keep in groups of less than 20 animals, rarely gather in herds of several hundred individuals. They are often found together with Pacific white-sided dolphins, sometimes they accompany groups of fish-eating killer whales for some time. As a rule, they do not jump out of the water. They can dive to a depth of 500 m. They are in fast motion all the time, the speed reaches 37 km / h, they like to ride on the bow wave of a fast-moving vessel. Characterized by a rapid change of the to a new one – within about a week. They feed on fish and cephalopods, usually hunt at night. They reach sexual maturity by 3.5 years. Pregnancy 10-12 months, lactation about 4 months. Life expectancy up to 22 years.<br><br>In captivity, usually few live, although a male named Marty caught near Anacapa Island in 1965 lived in Point Mugu for 21 months, consuming 12-14 kg of food daily.<br>