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Difference between revisions of "Antarctic krill"
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The main spawning season of Antarctic krill is from January to March, both above the continental shelf and also in the upper region of deep sea oceanic areas. In the typical way of all krill, the male attaches a spermatophore to the genital opening of the female. For this purpose, the first pleopods (legs attached to the abdomen) of the male are constructed as mating tools. Females lay 6,000–10,000 eggs at one time. They are fertilized as they pass out of the genital opening. | The main spawning season of Antarctic krill is from January to March, both above the continental shelf and also in the upper region of deep sea oceanic areas. In the typical way of all krill, the male attaches a spermatophore to the genital opening of the female. For this purpose, the first pleopods (legs attached to the abdomen) of the male are constructed as mating tools. Females lay 6,000–10,000 eggs at one time. They are fertilized as they pass out of the genital opening. | ||
At 15 mm, the juvenile krill resembles the habitus of the adults. Krill reach maturity after two to three years. Like all crustaceans, krill must moult | At 15 mm, the juvenile krill resembles the habitus of the adults. Krill reach maturity after two to three years. Like all crustaceans, krill must moult in order to grow. Approximately every 13 to 20 days, krill shed their chitinous exoskeleton and leave it behind as exuvia. | ||
==Food== | ==Food== | ||
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==Ecology== | ==Ecology== | ||
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, | 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 seals, [[crabeater seal]]s, [[glacial squid]], [[Crocodile icefish|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. [[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. | 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. | ||