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ÁÕàÃ×èͧ¢Í§à¢ÒÁÒ¢ÂÒÂãËéÍèÒ¹´éǤèÐ GENERAL DESCRIPTION
The right whales (Eubalaena spp.) are baleen whales with bow-shaped lower jaw and a head that is up to one-quarter of the body length. The head is hairier than most whales; up to 300 hairs are found on the tip of the lower jaw and 100 are on the upper jaw. There are also callosities (a series of horny growths) behind the blowhole, on the chin, above the eyes, on the lower lip, and on the rostrum (the beak-like upper jaw). Right whales are similar to bowhead whales, but smaller. These whales are rich in blubber and have 2 blowholes. The eyes are very small and lips are large. Right whales were named by whalers who considered them the "right" whales to hunt, since they were rich in blubber, they were easy to catch (they are relatively slow swimmers) and they floated after being killed.
SIZE
Northern right whale females grow to be about 50 feet (15.2 m) long, males are about 49 feet (15 m) long. They weigh approximately 120,000 pounds (54,000 kg). Southern right whale females are about 54 feet (16.5 m) long, males are about 50 feet (15.2 m) long. The females are slightly larger than males, as with all baleen whales.
SKIN, SHAPE, AND FINS
The right whale's skin is usually black to dark gray with white and/or brown patches. Calves are blue to gray colored.
Right whales have no dorsal fin and no throat grooves. They have large flippers.
DIET AND BALEEN
Right whales (like all baleen whales) are seasonal feeders and carnivores that filter feed plankton and tiny crustaceans like copepods, krill, pteropods, etc., from the water. Right whales are skimmers, filter feeders that swim slowly with their mouth open, constantly eating. On occasion, they are also bottom feeders, eating benthic prey from the mud on the ocean floor. The fine baleen hairs can filter out very tiny prey including copepods, steropods, euphasiids and mysids (tiny crustaceans).
The right whales have about 200-270 pairs of black baleen plates with gray-black to white bristles hanging from the jaws. The baleen is long and very fine; baleen plates are up to 9.5 feet (3 m) long.
SOCIAL GROUPS
Right whales only long-term bonds are between mother and calf.
SPOUTING - BREATHING
Right whales breathe air at the surface of the water through 2 blowholes located near the top of the head.
HABITAT
Right whales live in temperate and cool seas in both hemispheres at the surface of the ocean. Southern right whales live at latitudes between 20°-55° but will occasionally venture down to 63°.
CLASSIFICATION
Right whales (Eubalaena spp.) are baleen whales (Suborder Mysticeti).
Kingdom..... Animalia (animals)
Phylum........Chordata (vertebrates)
Class...........Mammalia (mammals)
Order...........Cetacea (whales and dolphins)
Suborder.....Mysticeti (baleen whales)
Family..........Balaenidae
Genus.........Eubalaenaÿ
SPECIES OF RIGHT WHALESThe number of species of right whales is in dispute; most biologists believe there are two species, Eubalaena glacialis, the northern right whale, and Eubalaena australis, the southern species. Some believe that right whales from the north Pacific should be considered a third species, Eubalaena japonica. The right whales are probably an example of a species that is in the process of diverging into separate species after prolonged separation across the globe.ÿ
REPRODUCTIONThe right whale gestation period is about 12 months and the calf is born tail first (this is normal for cetaceans) and near the surface. The newborn instinctively swims to the surface within 10 seconds for its first breath; it is helped by its mother, using her flippers. Within 30 minutes of its birth the baby whale can swim. The newborn calf is about 16-19 feet (4.8-6 m) long. Twins are rare; there is usually one calf. The baby is nurtured with its mother's milk and is weaned in about 1 year when the calf is roughly 28 feet long.
LIFE SPANRight whales may have a life expectancy of over 60 years, although this figure is not at all certain (very little is known about these whales).
POPULATION COUNTNorthern right whales are near extinction due to past hunting pressures and are an endangered species; it is estimated that there are 500-1,000 northern right whales alive and they are near extinction. The southern whales are more abundant (there are perhaps 3,000 alive) but are vulnerable to extinction and are also an endangered species[/color].
¢éÍÁÙŨҡ http://www.enchantedlearning.com/subjects/whales/species/Rightwhale.shtml 
