Vertical distribution and abundance of juvenile chaetognaths in the Weddell Sea (Antarctica)

The composition, abundance and vertical distribution of chaetognaths were analysed along a transect in the Weddell Sea during late spring. Three species were identified: Eukrohnia hamata (90.8%), Sagitta marri (6.4%) and S. gazellae (2.8%). Only juvenile stages were collected in the samples, a result related both to the type of sampling gear employed (mesh size: 100 μm) and the species' life-cycles. The vertical distributions showed that the juvenile stages of these species tended to aggregate at considerable depth (1000–500 m). It is postulated that this pattern may be related to the life-cycles of these species in association with seasonal Antarctic conditions, similar to the pattern postulated for krill and other polar crustaceans. Accepted: 10 July 2000