The reproductive potential of three euphausiid species from the southern Benguela region

Abstract

Relative sizes of oocytes and number of ripe Stage IV eggs were measured in the ovaries of three euphausiid species: Nyctiphanes capensis Hansen, Euphausia lucens Hansen, and Euphausia hanseni Zimmer. The number of Stage IV eggs per female was directly related to body length for all three species, and was used as an estimate of brood size. The number of eggs found in the brood pouch of Nyctiphanes capensis was lower than counts of Stage IV eggs in the ovary. Since all the Stage IV eggs were laid (none present in the ovaries of females with eggs in the brood pouch), this implies loss of eggs from the brood pouch. In all three species, the presence of more than one stage of ova developing in the ovaries suggests the production of multiple broods.