Calanoida

Calanoids are a type of copepod, which are small crustaceans found in marine and freshwater environments. They are ecologically significant as a food source for many fish species. While most copepods are free-living, some are parasitic.1

Calanoids belong to the order Calanoida, and a genus within this order is named Calanus. These copepods are typically reddish and are a primary food source for fish like herring and mackerel. The term "calanid" refers to a calanoid copepod.23

Copepods generally lack compound eyes and a carapace, unlike most other crustaceans. They vary greatly in size, from less than a millimeter to over 30 cm for some parasitic species.1