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Krill

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Starfish13
924854.  Wed Jul 18, 2012 9:26 am Reply with quote

Euphausiids* are small shrimp-like marine crustaceans, commonly known as krill. Krill species form a vital part of many oceanic food webs, feeding on phytoplankton and being consumed in turn by larger animals, including fish, squid, seals, penguins and whales. They form pretty much exclusively the diet of the blue whale (Balaenoptera musculus).

Krill species are found worldwide, from Arctic to Antarctic waters and from surface waters to depths of around 4000m. Many species also make a diel vertical migration within the water column, moving towards the surface at night then returning to depth during the day.

In terms of biomass, the Antarctic krill (Euphausia superba) is considered to be the most abundant animal species on the planet. It is estimated that there are about 500million tonnes of Antarctic krill, in contrast to around 280**million tonnes of humans and 0.5million tonnes of blue whales. The species closest to reaching the levels of krill may be domesticated livestock, especially cattle.

*The name of the order is derived from the Greek for "ooh, pretty shiny-shiny" or something like that. Most species bioluminesce.

**fresh biomass, not dried, depending on source.

 
Spud McLaren
938567.  Wed Sep 12, 2012 4:14 pm Reply with quote

When disturbed, a swarm scatters, and some individuals have even been observed to moult instantaneously, leaving the exuvia behind as a decoy.
Starfish13 wrote:
Krill species are found worldwide, from Arctic to Antarctic waters and from surface waters to depths of around 4000m. Many species also make a diel vertical migration within the water column, moving towards the surface at night then returning to depth during the day.
Generally, the species found in high-latitude regions outlive those found in tropical regions, by as much as a factor of 6.

 
germananglophile
988663.  Fri Apr 12, 2013 7:03 pm Reply with quote

Starfish13 wrote:
[i] 0.5million tonnes of blue whales.


Come on. THIS TIME. This time for sure, Alan. :D

 

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