Creature Feature – Krill

This week is the letter ‘K’, and today’s featured creature is Krill.

The common name for any member of the crustacean order Euphausiacea, Krill are in the same class of animal as crabs, lobsters and crayfish, as well as shrimp and woodlice. 82 species of krill have been described.


Kingdom: Animalia

Phylum: Arthropoda

Class: Malacostraca

Superoder: Eucarida

Order: Euphausiacea

Krill Fact File

? Size: Individuals from some species can reach up to 6cm in length and weigh up to 1g

? Distribution: They occur worldwide in all oceans, although many individual species are endemic (found in a single defined geographic location). They congregate in dense swarms of more than 10,000 individuals per cubic meters of water

? Diet: They feed on phytoplankton (microscopic marine algae) and zooplankton (small, free-floating aquatic microorganisms including crustaceans, insect larvae, and aquatic mites)

? Behaviour: Crustaceans usually grow by moulting their hard shell (exoskeleton), expanding the new one and then growing into it. When the exoskeleton becomes tight again, the moulting and growing process starts again. In most crustaceans, the moulting tends to slow down as the animal grows older, and stops altogether in adulthood. However, these species retain the ability to moult for life. They use this ability to continue growing and reducing their body size to help them survive

? IUCN Status: Least Concern. While they are not believed to be threated with extinction, the 2022 report from the Intergovernmental Panel on Climate Change indicated that there’s a high likelihood that climate-induced stressors would soon present considerable risks for the global supply of krill