The two genera of euphausiid which have not been recorded in the South Atlantic are both monospecific, cold-water Northern Hemisphere endemics which have never been recorded in the Southern Hemisphere (Tessarabrachion oculatum and Meganyctiphanes norvegica). Of the 86 species of euphausiid found worldwide, 61 have been recovered from the South Atlantic: the absentees all display limited distribution patterns and are either endemic to the Northern Hemisphere (especially members of the genus Thysanoessa), or to the equatorial regions of the Pacific and/or Indian Oceans. While tropical and subtropical waters of the Indian Ocean can penetrate the South Atlantic via the Agulhas Current, tropical and subtropical waters of Pacific origin do not move into the South Atlantic around Cape Horn owing to both restricted circulation and the latitudinal extension of the South American continent. Consequently, few of the epipelagic euphausiid species routinely encountered in the Indian Ocean basin fail to penetrate the South Atlantic (exceptions are restricted to coastal areas in the easternmost sector), whilst the only equatorial Pacific species found in the region are those with circumbglobal distribution patterns. It should be noted that not all of the tropical and subtropical Indian Ocean species that manage to penetrate the South Atlantic via the Agulhas Current persist in this region, owing to the relatively cold and variable environment into which they are transported. Indeed, many are confined to the region off the Cape of Good Hope and this reflects the limited penetration of Agulhas Current water (see analysis below). Most of those that maintain populations in the region also tend to display circumglobal patterns of distribution. The endemics to the South Atlantic are either restricted to neritic (Nyctiphanes capensis) and shelf (Euphausia hanseni) waters on the eastern seaboard, or are equatorial in distribution (Euphausia americana and Euphausia krohni). While centres of abundance for most of these endemics are located in the South Atlantic (exception is Euphausia krohni), they all show restricted patterns of distribution in the Northern Hemisphere which tend to reflect patterns of surface current flow. The absence of these species from other ocean basins reflects the restricted movement water between the Atlantic and other oceans, and suggests a relatively recent origin.