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Difference between revisions of "Antarctic krill"
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Antarctic krill are the keystone species of the [[Antarctica|Antarctic]] ecosystem beyond the coastal shelf, and provides an important food source for whales, [[leopard seal]]s, [[fur seal]]s, [[crabeater seal]]s, [[squid]], [[icefish]], penguins, albatrosses and many other species of birds. | Antarctic krill are the keystone species of the [[Antarctica|Antarctic]] ecosystem beyond the coastal shelf, and provides an important food source for whales, [[leopard seal]]s, [[fur seal]]s, [[crabeater seal]]s, [[squid]], [[icefish]], penguins, albatrosses and many other species of birds. | ||
Crabeater seals have even developed special teeth as an adaptation to catch this abundant food source: its unusual multilobed teeth enable this species to sieve krill from the water. Its dentition looks like a perfect strainer, but how it operates in detail is still unknown. Crabeaters are the most abundant seal in the world; 98% of their diet is made up of '' E. superba''. These seals consume over 63 million tonnes of krill each year. | Crabeater seals have even developed special teeth as an adaptation to catch this abundant food source: its unusual multilobed teeth enable this species to sieve krill from the water. Its dentition looks like a perfect strainer, but how it operates in detail is still unknown. Crabeaters are the most abundant seal in the world; 98% of their diet is made up of '' E. superba''. These seals consume over 63 million tonnes of krill each year. [[Leopard seal]]s have developed similar teeth and consume approximately 45% krill in their diets. All seals combined consume 63–130 million tonnes, all whales 34–43 million tonnes, birds 15–20 million tonnes, squid 30–100 million tonnes, and fish 10–20 million tonnes, adding up to 152–313 million tonnes of krill consumption each year. | ||
[[Leopard seal]]s have developed similar teeth and consume approximately 45% krill in their diets. All seals combined consume 63–130 million tonnes, all whales 34–43 million tonnes, birds 15–20 million tonnes, squid 30–100 million tonnes, and fish 10–20 million tonnes, adding up to 152–313 million tonnes of krill consumption each year. | |||
The size step between krill and its prey is unusually large: generally it takes three or four steps from the small phytoplankton cells to a krill-sized organism (via small copepods, large copepods, mysids to 5 cm fish. ''E. superba'' lives only in the Southern Ocean. In the North Atlantic, ''Meganyctiphanes norvegica'' and in the Pacific, ''Euphausia pacifica'' are the dominant species. | The size step between krill and its prey is unusually large: generally it takes three or four steps from the small phytoplankton cells to a krill-sized organism (via small copepods, large copepods, mysids to 5 cm fish. ''E. superba'' lives only in the Southern Ocean. In the North Atlantic, ''Meganyctiphanes norvegica'' and in the Pacific, ''Euphausia pacifica'' are the dominant species. | ||