pacific+white+sided+dolphin

 Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Cetacea Family: Delphinidae Genus: //Lagenorhynchus// Species: //acutus//
 * Taxonomy **

Pacific White-Sided Dolphins The Pacific White-sided Dolphin was named by Smithsonian mammalogist Theodore Nicholas Gill in 1865. The Pacific White-sided Dolphin is morphologically similar to the Dusky Dolphin, which is found in the southern Pacific. Genetic analysis by Frank Cipriano suggests the two species diverged about two million years ago. Though both are traditionally placed in the genus //Lagenorhynchus//, molecular analyses indicate that they are closer to dolphins of the genus. The new genus has been proposed for these species.
 * Habitat**

The Pacific White-sided Dolphin has three colors. The chin, throat and belly are creamy white. The beak, flippers, back, and dorsal fin are a dark gray. There are light gray patches on the sides and a further light gray stripe running from above the eye to below the dorsal fin where it thickens along the tail stock. A dark gray ring surrounds the eyes.
 * Physiology**

The range of the Pacific White-sided Dolphin arcs across the cool to temperate waters of the north Pacific. Sightings go no further south than the South China Sea on the western side and the Baja California peninsula on the eastern. Populations may also be found in the Sea of Japan. In the northern part of the range, some individuals may be found in the Bering Sea. The dolphins appear to follow some sort of migratory pattern—on the eastern side they are most abundant off the California shore in winter, but further north Oregon, Washington in summer. Their preference for off-shore deep waters appears to be year-round.

The total population may be as many as 1 million. However, the tendency of Pacific White-sided Dolphins to approach boats complicates precise estimates via sampling.

Adults average 2.3 metres long, and weigh up to 180 kilograms, and most live from 30 to 40 years. Dolphins are perfectly adapted to their environment. They have strong eye muscles and can change the shape of their eye lens to focus in air and water. Dolphins also have a highly developed sense of hearing, and are very vocal animals, communicating with high-pitched squeals using air trapped in their blowholes. Clicking sounds are used for echolocation, helping dolphins navigate and locate prey. Dolphins feed on creatures such as hake, anchovies, squid and sardines. They grip prey with their teeth, and swallow it whole, head first. Dolphins have few predators, but transient Killer Whales will sometimes prey upon them.
 * Reproduction**

**SKELETON OF A WHITE SIDED DOLPHIN** Dolphins have a streamlined fusiform body, adapted for fast swimming. The tail fin, called the fluke, is used for propulsion, while the pectoral fins together with the entire tail section provide directional control. The dorsal fin, in those species that have one, provides stability while swimming.The head contains the melon, a round organ used for echolocation. In many species, elongated jaws form a distinct beak; species such as the bottlenose have a curved mouth which looks like a fixed smile. Some species have up to 250 teeth. Dolphins breathe through a blowhole on top of their head. The trachea is anterior to the brain. The dolphin brain is large and highly complex, and is different in structure from that of most land mammals.