1. Krill Facts Center

Tiny but mighty, Krill represent a major link in the Earth’s marine ecosystems and the global food chain. Read on for more…

What is krill?

Krill are zooplankton invertebrates that float in huge swarms in oceans all over the world. These swarms sometimes reaching densities they can turn the surface of the ocean pinkish-red.

Euphausia superba krill are the most common krill, found mostly in the waters of the Antarctic. Euphausia krill are at the very bottom of the food chain and can only found in the pristine oceans around Antarctcia, where there is very limited accumulation of contaminants.

How many different species of krill are they?

There are 85 known species of krill. Krill is comprised of two families the largest of which is Euphausiidae which contains 20 different genra, the largest of which is the Euphausia. The other family of Krill is the Bentheuphausia ampblyops, which lives in the deep waters (below 3,330 feet) and are the most primitive species of krill.

The most well known species of the Euphausiidae are the Antarctic Krill (Euphausia superba), Pacific krill (Euphausia pacifica) and Northern krill (Meganyctiphanes norvegica).

Actual Size: 2½ inches (or your pinky finger)


With large black eyes, krill are mostly transparent, although their shells have a bright red tinge. Their digestive system is usually visible. Krill have a hard exoskeleton, many legs which they use to swim and eat, and a segmented body.


Antarctic krill are one of the most abundant animal species, there are about 500 million tons of krill in the Southern Ocean.

Krill travel in swarms primarily as a defense mechanism to confuse predators that would pick out single krill. In additional efforts to avoid predators, krill are found to spend their day at greater depths in the ocean and rise during the night toward the surface. It has also been found that the deeper they go in the water, the more their activity lessens, to reduce the probability of encounters with predators as well as conserve their energy.


The lifespan of a krill is typically up to 10 years, six years on average which is not bad for a heavily sought after creature.

Life Cycle: The main spawning season of Antarctic Krill is from January to March, above the continental shelf. Female krill lay up to 10,000 eggs at a time, sometimes several times a season.

The eggs are spawned close to the surface and start sinking. In the open ocean they sink for about 10 days: the nauplii hatch at around 3000 m depth.

What do they eat?

Antarctic Krill are mainly herbivorous (they sometimes eat each other), feeding mostly on phytoplankton (microscopic suspended plants). They feed directly on phytoplankton, thereby using the primary production energy that phytoplankton derive from the sun in order to sustain their open ocean life cycle. Some krill also eat zooplankton

In winter they have to use other sources such as algae which grow on the underside of the ice, on the sea-floor. Krill can survive for long periods of time without food (up to 200 days) and can shrink in length as they starve.

How big are they?

They grow to a length of 2½ inches (6 centimeters), and weigh up to .07 ounces (2 grams).

Fun facts

Did you know, that...

  • Without Krill, the majority of life forms in the Antarctic would vanish.
  • Krill travel in swarms so dense they can be seen from space.
  • A krill is about the size of your pinky.
  • Krill is possibly the most abundant species on the planet. In fact, it's estimated that the total weight of all Antarctic krill is more than the total weight of all humans on Earth!
Interesting Facts:
  • 47
    number of
    who have signed the Antarctic Treaty

  • Winter
    as low as

  • Antarctica is
    1.5 times the size
    of the
    United States

  • There
    are no native land

  • 90%
    the world's
    is in Antarctica

  • 4,000

    Average Antarctic human population



  • the size, in inches, of the

  • 29
    number of
    that send scientists to conduct experiments in Antarctica

  • 10

    Number of

    human babies

    born in Antarctica

  • Summer
    maximum of 58F

  • 10,000
    number of
    a female krill lays at one time

  • 0

    Number of



    in Antarctica

  • 10
    number of years krill can

  • 1,000

    Average Antarctic human population


    the winter

  • If
    the sea level could rise
    200 feet

  • Krill can go for up to



    without eating

  • 70%
    of world's fresh water

  • Antarctica
    is the driest
    on Earth
    (less than 2 inches of rain per year)

  • 2
    of precipitation fall in Antarctica
    each year
    on average

  • 98%
    of Antarctica is covered by fresh water ice

  • 0
    number of

    that rule Antarctica

  • Krill is more than
    the total weight of all humans
    on earth

  • 2,000,000
    tons of krill
    in a swarm