In pelagic ecosystems in all oceans, euphausiids (krill) are important components of the zooplankton. In May–June 2019, euphausiids were investigated from temperate to tropical waters along the 110°E meridian, originally surveyed in 1962–1963 during the

Because adult females of the closely related species Euphausia hemigibba, E. pseudogibba, E. paragibba and E. gibba are difficult to distinguish, the external morphology of the femal external genitalia in these species is described. In the four species,

The first comprehensive phylogenetic study of Euphausiacea (all 86 valid species) is presented. It is based on four molecular markers and 168 morphological characters (including 58 characters of the petasma). Phylogenetic analyses support the monophyly