---
title: "What the sources say about the Antarctic Krill | AnimalTracks.wiki"
description: "51 claims from the Antarctic Krill profile, each beside the words of the source that backs it."
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---

# What the sources say about the Antarctic Krill (*Euphausia superba*)

> 51 claims from the Antarctic Krill profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Antarctic Krill](https://animaltracks.wiki/animals/antarctic-krill/)

## Antarctic krill. Australian Antarctic Program, Australian Antarctic Division.

https://www.antarctica.gov.au/about-antarctica/animals/krill/

| The page says | The source says |
| :--- | :--- |
| A crustacean about 6 centimeters long, so abundant it can turn the sea reddish-brown, that most larger Antarctic animals depend on, directly or indirectly. | Adult Antarctic krill are approximately 6 cm in length ... They are frequently found in such abundance that they colour the sea a reddish-brown. ... Most of the larger Antarctic animals (seals, whales, seabirds, fish and squid) depend on Antarctic krill, directly or indirectly. (note: "about" keeps "approximately"; "so abundant it can turn" for "frequently found in such abundance that they colour") |
| Southern Ocean south of the Antarctic Convergence | Antarctic krill is one of 5 species of krill that lives in the Southern Ocean, south of the Antarctic convergence. |
| Mainly phytoplankton; in winter, algae growing under the pack ice, seafloor detritus and other animals | The primary food of krill is phytoplankton ... In winter, krill have to use other food sources such as algae growing on the underside of the pack ice, detritus on the sea-floor or the other animals in the water. |
| An estimated 400 million tonnes in the Southern Ocean | there is an estimated 400 million tonnes of Antarctic krill in the Southern Ocean |
| the ability to shrink, burning its own body protein as fuel, when food is scarce in winter | they must survive the winter months when food is scarce. ... They use this ability to continue growing and reducing their body size to help them survive. 'Downsizing' enables Antarctic krill to use their own body proteins as a source of fuel. |
| The Antarctic krill (Euphausia superba) is one of the most abundant animal species on the planet. | Antarctic krill is one of the most abundant and successful animal species on the planet. |
| It lives in the Antarctic waters of the Southern Ocean. | Antarctic krill is one of 5 species of krill that lives in the Southern Ocean ... There are 5 species of krill found in Antarctic waters. |
| An adult is about 6 centimeters long and weighs more than a gram. | Adult Antarctic krill are approximately 6 cm in length and weigh over one gram. (note: AAD (current page) over ADW's older 5-6.5 cm and 2 g average) |
| Scientists estimate it lives for 5 to 10 years. | It is estimated that Antarctic krill live for 5 to 10 years |
| Krill gather in schools or swarms, which can hold as many as 30,000 animals in one cubic meter of water. | Antarctic krill aggregate in schools or swarms, where the density of the animal can be as high as 30,000 individuals per cubic metre. |
| They are often so abundant that they color the sea reddish-brown. | They are frequently found in such abundance that they colour the sea a reddish-brown. (note: "so abundant that" for "such abundance that"; "often" for "frequently") |
| Scientists estimate there are 400 million tonnes of Antarctic krill in the Southern Ocean. | there is an estimated 400 million tonnes of Antarctic krill in the Southern Ocean |
| In winter, krill turn to other food: algae growing on the underside of the pack ice, detritus (bits of dead matter) on the seafloor, or other animals in the water. | In winter, krill have to use other food sources such as algae growing on the underside of the pack ice, detritus on the sea-floor or the other animals in the water. (note: "bits of dead matter" defines detritus; it is not a claim about krill) |
| Food is scarce then, and lab studies show Antarctic krill can survive more than 200 days of starvation. | they must survive the winter months when food is scarce. ... Laboratory studies have shown that Antarctic krill can survive more than 200 days of starvation. |
| They shrink as they starve. | They shrink in length as they starve. |
| Krill can molt (shed their hard outer shell) all their lives, and they use it to shrink as well as grow. | Crustaceans usually grow by moulting their hard shell (exoskeleton) ... Krill retain the ability to moult for life. They use this ability to continue growing and reducing their body size to help them survive. (note: "all their lives" for "for life") |
| This "downsizing" lets them burn their own body proteins as fuel. | 'Downsizing' enables Antarctic krill to use their own body proteins as a source of fuel. (note: "lets" for "enables") |
| At the end of summer, adults start to lose their sexual features. | At the end of summer, adult krill begin to lose their sexual characteristics. |
| After a series of molts they look like two-year-old juveniles again, and in spring they mature once more. | After a series of moults they again resemble two-year-old juveniles ... In spring, adults once more begin to develop sexual characteristics and become mature before the spawning season. |
| Most of the larger Antarctic animals (seals, whales, seabirds, fish and squid) depend on Antarctic krill, directly or indirectly. | Most of the larger Antarctic animals (seals, whales, seabirds, fish and squid) depend on Antarctic krill, directly or indirectly. |
| There is an estimated 400 million tonnes of Antarctic krill in the Southern Ocean. | there is an estimated 400 million tonnes of Antarctic krill in the Southern Ocean |
| Their swarms can hold as many as 30,000 animals in one cubic meter of water, and krill are often so abundant that they color the sea reddish-brown. | They are frequently found in such abundance that they colour the sea a reddish-brown. ... the density of the animal can be as high as 30,000 individuals per cubic metre (note: "so abundant" for "such abundance"; "often" for "frequently") |
| Most of the larger Antarctic animals, such as seals, whales, seabirds, fish and squid, depend on them, directly or indirectly. | Most of the larger Antarctic animals (seals, whales, seabirds, fish and squid) depend on Antarctic krill, directly or indirectly. |
| In winter, krill turn to other food: algae growing on the underside of the pack ice, detritus on the seafloor, or other animals in the water. | In winter, krill have to use other food sources such as algae growing on the underside of the pack ice, detritus on the sea-floor or the other animals in the water. |
| Lab studies show they can survive more than 200 days of starvation, and they shrink as they starve, burning their own body proteins as fuel. | Laboratory studies have shown that Antarctic krill can survive more than 200 days of starvation. ... 'Downsizing' enables Antarctic krill to use their own body proteins as a source of fuel. ... They shrink in length as they starve. |
| After a series of molts, adults look like two-year-old juveniles again, and in spring they mature once more. | After a series of moults they again resemble two-year-old juveniles ... In spring, adults once more begin to develop sexual characteristics and become mature before the spawning season. |

## Euphausia superba (Antarctic krill). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Euphausia_superba/

| The page says | The source says |
| :--- | :--- |
| Krill usually feed by using their chest legs to form a watertight basket around a pocket of water and food. | Usually, Antarctic krill feed by using their thoracic endopodites to create a watertight feeding basket, which encloses a pocket of food and water. (note: "chest legs" is a plain gloss of thoracic endopodites (branches of the thoracic legs)) |
| Water is squeezed out sideways through fine bristles. | Water is then filtered out laterally by compression-filtration through setae. |
| The phytoplankton (microscopic ocean plants) left in the basket is brushed forward into the mouth. | Phytoplankton remains caught in the feeding basket as water is filtered out, and is brushed forward by the setae into the mouth for ingestion. (note: the gloss is AAD's definition: "phytoplankton, which are microscopic ocean plants") |
| They sit near its mouthparts, at its reproductive organs and at the base of its swimming legs, and they give off blue light. | There are luminous organs called photophores located near the mouthparts, at the genitals (located on the cephalothorax), and at the base of the abdominal pleopods (which are the forked limbs these animals use for swimming). These photophores produce a blue light. |

## Kawaguchi & Nicol (2015). Euphausia superba. The IUCN Red List of Threatened Species 2015: e.T64239743A64239951.

https://doi.org/10.2305/iucn.uk.2015-2.rlts.t64239743a64239951.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | Least Concern (note: read through GBIF's copy of the Red List per verify:quotes; category check, not the assessment's text) |

## Hill (2012). Prospects for a Sustainable Increase in the Availability of Long Chain Omega 3s: Lessons from the Antarctic Krill Fishery. Omega-6/3 Fatty Acids.

https://doi.org/10.1007/978-1-62703-215-5_14

| The page says | The source says |
| :--- | :--- |
| adults mostly in the top 150 meters, but found as deep as 3,500 meters | Adult Antarctic krill occur mainly in the upper 150m of the water column 41 and are best known from open water habitats, but they also occur under sea ice 42 and at depths of upto 3,500m 41 (note: the source writes the units with no space (150m, 3,500m); the profile adds the space, the same figures) |

## Grinnell et al. (1988). Eye/Photophore Coordination and Light-Following in Krill, Euphausia Superba. Journal of Experimental Biology.

https://doi.org/10.1242/jeb.134.1.61

| The page says | The source says |
| :--- | :--- |
| photophores on muscular stalks that aim their light away from incoming light | Eight of the 10 photophores of the Antarctic krill, Ettphausia superba, are located at the ends of muscular stalks and exhibit coordinated orientation responses to incident white light; light emitted from the photophores is directed away from the incident light. (note: eight of the ten are on stalks; the stat does not say all of them are) |
| A krill has ten photophores, organs that make light. | Eight of the 10 photophores of the Antarctic krill (note: ADW: "luminous organs called photophores") |
| Eight of the ten sit at the tips of muscular stalks. | Eight of the 10 photophores of the Antarctic krill, Ettphausia superba, are located at the ends of muscular stalks |
| In experiments, when white light shone on a krill, the stalks turned, pointing their light away from it, and the eyes turned at the same time. | Eight of the 10 photophores of the Antarctic krill, Ettphausia superba, are located at the ends of muscular stalks and exhibit coordinated orientation responses to incident white light; light emitted from the photophores is directed away from the incident light. Moreover, eye rotation occurs synchronously with photophore movement. |
| Removing the eyes, or covering the head with a hood, stopped the photophores moving together. | eye removal or covering the head with an opaque hood eliminated coordinated photophore movement |
| The researchers concluded that krill need vision to aim their lights. | We conclude that vision is necessary for light-following responses by the photophores. |
| Krill have ten photophores, organs that make light, and eight of them sit at the tips of muscular stalks. | Eight of the 10 photophores of the Antarctic krill, Ettphausia superba, are located at the ends of muscular stalks |
| When white light shone on krill, the stalks turned, pointing the light they gave off away from it, and the eyes turned at the same time. | Eight of the 10 photophores of the Antarctic krill, Ettphausia superba, are located at the ends of muscular stalks and exhibit coordinated orientation responses to incident white light; light emitted from the photophores is directed away from the incident light. Moreover, eye rotation occurs synchronously with photophore movement. |
| Removing the eyes, or covering the head with a hood, stopped the photophores moving together, and the researchers concluded that krill need vision to do it. | eye removal or covering the head with an opaque hood eliminated coordinated photophore movement. We conclude that vision is necessary for light-following responses by the photophores. |

## Dawson et al. (2018). Turning microplastics into nanoplastics through digestive fragmentation by Antarctic krill. Nature Communications.

https://doi.org/10.1038/s41467-018-03465-9

| The page says | The source says |
| :--- | :--- |
| Antarctic keystone | Antarctic krill ( Euphausia superba , hereafter ‘krill’), a keystone species in the Antarctic ecosystem |
| Filter feeders may be the animals most likely to swallow microplastics (tiny pieces of plastic), because filter feeding is fairly unselective. | Planktonic suspension and filter feeders may be the most susceptible to microplastic ingestion due to the relatively indiscriminate nature of this feeding strategy (note: "fairly unselective" for "relatively indiscriminate"; "may" kept; "because" for "due to") |
| A krill chews its food with its mandibles (jaws), then passes it into its stomach and gastric mill, where it is mixed with digestive enzymes and chewed again. | Food particles are retained on the basket and are then transported to the mandibles for mastication ... Food is then directed through the short oesophagus into the stomach and gastric mill where it is mixed with digestive enzymes for further mastication (note: "chews" and "chewed again" for mastication and further mastication) |
| In a lab study, researchers fed Antarctic krill plastic beads averaging 31.5 micrometers wide (a micrometer is a millionth of a meter). | To determine the effect of ingestion on microplastic beads we exposed krill to a 4-day static renewal assay ... Beads in the stock suspension had a mean diameter of 31.5 µm |
| Every krill ended up holding a mix of whole beads and fragments. | We found all krill contained a mixture of whole PE microplastic beads and PE fragments |
| Some pieces were less than 1 micrometer across. | Ingested microplastics (31.5 µm) are fragmented into pieces less than 1 µm in diameter. (note: "some pieces": the results give a mix of whole beads and fragments with a 7.1 µm mean, so not every piece was this small) |
| The authors think most of the grinding happened in the stomach and gastric mill. | The bulk of plastic maceration presumably took place in the stomach and gastric mill (note: "think" keeps "presumably"; "most of the grinding" for "the bulk of plastic maceration") |
| Earlier feeding studies had shown microplastics either passing through an animal unchanged or being small enough already to cross into its body. | Previous feeding studies have shown spherical microplastics either; pass unaffected through an organism and are excreted, or are sufficiently small for translocation to occur. (note: "cross into its body" glosses translocation (the paper: to the haemolymph)) |
| The authors called krill's grinding a new pathway, which gives krill, and potentially other species, a new role in what happens to plastic in the ocean. | We identify a new pathway; microplastics are fragmented into sizes small enough to cross physical barriers, or are egested as a mixture of triturated particles. ... introduces a new role of Antarctic krill, and potentially other species, in the biogeochemical cycling and fate of plastic |

## Bar-On, Phillips & Milo (2018). The biomass distribution on Earth. Proceedings of the National Academy of Sciences.

https://doi.org/10.1073/pnas.1711842115

| The page says | The source says |
| :--- | :--- |
| A 2018 study of all the living matter on Earth, measured by the carbon in it, found Antarctic krill on a par with humans or cows. | the Antarctic krill species Euphausia superba contributes ≈0.05 Gt C to global biomass ( 24 ), similar to other prominent species such as humans or cows (note: 2018 is the paper's year (reference biomass-2018); "all the living matter on Earth" for "global biomass"; "on a par with" for "similar to"; Gt C is carbon mass, which the sentence names) |