This program is a revised edition of the Identification Manual by Elena L. Markhaseva (1996),

Calanoid Copepods of the Family Aetideidae of the World Ocean.

[Proceedings of the Zoological Institute, Russian Academy of Sciences, St. Petersburg, volume 268. ISSN 0206-0477]. For the first time a fully illustrated, interactive key is presented to the species of this family. Only those few species were excluded from the Manual and this program which were inadequately described and no material of which was seen by the author.

The calanoid copepods are free-living, planktonic crustaceans, which form an important link in the food chain of the marine environment, forming the food source of economically important fishes like herring, but also of some whales and seals. The 180 known species of the family Aetideidae are predominantly oceanic, occurring in tropical to polar waters and in all vertical ranges of the pelagic zone. Many species belong to the deep-water plankton or inhabit the hyperbenthic environment. Only a few species inhabit brackish or fresh waters.