Post by Life on Feb 2, 2014 20:34:52 GMT 5
Taxonomy:
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Balaenopteridae
Genus: Balaenoptera
Species: musculus
Subspecies:
Species Description:
The blue whale is species of baleen whale found worldwide. Blue whales in the Northern Hemisphere are generally smaller than those in the Southern Ocean. In the North Atlantic and North Pacific, they can grow up to about 88 feet (27 m), but, in the Antarctic, they can reach a up to about 108 feet (33 m) and can weigh more than 330,000 pounds (150,000 kg). As is true of other baleen whale species, female blue whales are somewhat larger than males.
Blue whales have a long-body and comparatively slender shape, a broad, flat "rostrum" when viewed from above, a proportionately smaller dorsal fin than other baleen whales, and a mottled gray color pattern that appears light blue (hence, the "blue" whale) when seen through the water.
The primary and preferred diet of blue whales is krill (euphausiids). In the North Atlantic, blue whales feed on two main euphausiid species (Thysanoëssa inermis and Meganyctiphanes norvegica). In addition, T. raschii and M. norvegica have been recorded as important food sources of blue whales in the Gulf of St. Lawrence. In the North Pacific, blue whales prey mainly on Euphausia pacifica and secondarily on T. spinifera. While other prey species, including fish and copepods, may be part of the blue whale diet, these are not likely to contribute significantly.
Scientists have yet to discern many details regarding the life history of the blue whale. The best available science suggests the gestation period is approximately 10-12 months and that blue whale calves are nursed for about 6-7 months. Most reproductive activity, including births and mating, takes place during the winter. Weaning probably occurs on, or en route to, summer feeding areas. The average calving interval is probably two to three years. The age of sexual maturity is thought to be 5-15 years. There are no known differences in the reproductive biology of blue whales in the North Pacific and North Atlantic oceans.
Habitat:
Blue whales are found worldwide, from sub-polar to sub-tropical latitudes. Poleward movements in spring allow the whales to take advantage of high zooplankton production in summer. Although the species is often found in coastal waters, blue whales are thought to occur generally more offshore than other whales, like humpback whales.
Distribution:
Blue whales are found in all oceans and are separated into populations by ocean basin in the North Atlantic, North Pacific, and Southern Hemisphere. They follow a seasonal migration pattern between summering and wintering areas, but some evidence suggests that individuals remain in certain areas year-round. The extent of knowledge concerning distribution and movement varies with area, and migratory routes are not well known. In general, distribution is driven largely by food requirements. For example, they occur in waters where krill is concentrated.
In the North Atlantic Ocean, blue whale range extends from the subtropics to the Greenland Sea. Blue whales are most frequently sighted in the waters off eastern Canada, with the majority of recent records from the Gulf of St. Lawrence, where they are present throughout most of the year. They are most common during the summer and fall feeding seasons and typically leave by early winter. Although they are rare in the shelf waters of the eastern U.S., occasional sightings of blue whales have been made off Cape Cod. It is believed this region may represent the current southern limit of the blue whales' feeding range. In addition, some evidence suggests that blue whales occur infrequently in the Gulf of Mexico and the Caribbean. Blue whales in the North Atlantic probably exist in two distinct populations.
In the North Pacific Ocean, the blue whale's range extends from Kamchatka to southern Japan in the west and from the Gulf of Alaska and California south to Costa Rica in the east. They occur primarily south of the Aleutian Islands and the Bering Sea.
Full read: www.nmfs.noaa.gov/pr/species/mammals/cetaceans/bluewhale.htm
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Balaenopteridae
Genus: Balaenoptera
Species: musculus
Subspecies:
- Northern Hemisphere blue whale (B. m. musculus)
- Antarctic blue whale (B. m. intermedia)
- Pygmy blue whale (B. m. brevicauda)
Species Description:
| Weight: | up to 330,000 pounds (150,000 kg) |
| Length: | up to 88-108 feet (27-33 m), depending on location (blue whales are largest in the Antarctic) |
| Appearance: | long body with mottled gray color pattern that appears light blue when seen through the water |
| Lifespan: | unknown, but sexually mature around 5-15 years |
| Diet: | krill |
| Behavior: | reproductive activity, including births and mating, mostly takes place during the winter |
The blue whale is species of baleen whale found worldwide. Blue whales in the Northern Hemisphere are generally smaller than those in the Southern Ocean. In the North Atlantic and North Pacific, they can grow up to about 88 feet (27 m), but, in the Antarctic, they can reach a up to about 108 feet (33 m) and can weigh more than 330,000 pounds (150,000 kg). As is true of other baleen whale species, female blue whales are somewhat larger than males.
Blue whales have a long-body and comparatively slender shape, a broad, flat "rostrum" when viewed from above, a proportionately smaller dorsal fin than other baleen whales, and a mottled gray color pattern that appears light blue (hence, the "blue" whale) when seen through the water.
The primary and preferred diet of blue whales is krill (euphausiids). In the North Atlantic, blue whales feed on two main euphausiid species (Thysanoëssa inermis and Meganyctiphanes norvegica). In addition, T. raschii and M. norvegica have been recorded as important food sources of blue whales in the Gulf of St. Lawrence. In the North Pacific, blue whales prey mainly on Euphausia pacifica and secondarily on T. spinifera. While other prey species, including fish and copepods, may be part of the blue whale diet, these are not likely to contribute significantly.
Scientists have yet to discern many details regarding the life history of the blue whale. The best available science suggests the gestation period is approximately 10-12 months and that blue whale calves are nursed for about 6-7 months. Most reproductive activity, including births and mating, takes place during the winter. Weaning probably occurs on, or en route to, summer feeding areas. The average calving interval is probably two to three years. The age of sexual maturity is thought to be 5-15 years. There are no known differences in the reproductive biology of blue whales in the North Pacific and North Atlantic oceans.
Habitat:
Blue whales are found worldwide, from sub-polar to sub-tropical latitudes. Poleward movements in spring allow the whales to take advantage of high zooplankton production in summer. Although the species is often found in coastal waters, blue whales are thought to occur generally more offshore than other whales, like humpback whales.
Distribution:
Blue whales are found in all oceans and are separated into populations by ocean basin in the North Atlantic, North Pacific, and Southern Hemisphere. They follow a seasonal migration pattern between summering and wintering areas, but some evidence suggests that individuals remain in certain areas year-round. The extent of knowledge concerning distribution and movement varies with area, and migratory routes are not well known. In general, distribution is driven largely by food requirements. For example, they occur in waters where krill is concentrated.
In the North Atlantic Ocean, blue whale range extends from the subtropics to the Greenland Sea. Blue whales are most frequently sighted in the waters off eastern Canada, with the majority of recent records from the Gulf of St. Lawrence, where they are present throughout most of the year. They are most common during the summer and fall feeding seasons and typically leave by early winter. Although they are rare in the shelf waters of the eastern U.S., occasional sightings of blue whales have been made off Cape Cod. It is believed this region may represent the current southern limit of the blue whales' feeding range. In addition, some evidence suggests that blue whales occur infrequently in the Gulf of Mexico and the Caribbean. Blue whales in the North Atlantic probably exist in two distinct populations.
In the North Pacific Ocean, the blue whale's range extends from Kamchatka to southern Japan in the west and from the Gulf of Alaska and California south to Costa Rica in the east. They occur primarily south of the Aleutian Islands and the Bering Sea.
Full read: www.nmfs.noaa.gov/pr/species/mammals/cetaceans/bluewhale.htm
