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

The composition, abundance and vertical distribution of chaetognaths were a nalysed along a transect in the Weddell Sea during late spring. Three speci es were identified: Eukrohnia hamata (90.8%), Sagitta marri (6.4%) and S. g azellae (2.8%). Only juvenile stages were collected in the samples, a resul t related both to the type of sampling gear employed (mesh size: 100 mum) a nd the species' life-cycles. The vertical distributions showed that the juv enile stages of these species tended to aggregate at considerable depth (10 00-500 m). It is postulated that this pattern may be related to the life-cy cles of these species in association with seasonal Antarctic conditions, si milar to the pattern postulated for krill and other polar crustaceans.