DISTRIBUTION OF CHAETOGNATHS IN THE AUSTRALIAN SECTOR OF THE SOUTHERN OCEAN DURING

Abstract: Studies on pelagic chaetognaths were carried out on the plankton samples collected during the R.V. HAKUHO MARU KH-83-4 cruise in the Australian Sector of the Southern Ocean as part of the BIOMASS SIBEX I (1983-1984) in-vestigations. The density of chaetognaths in the epipelagic layer in the Southern Ocean was 2.6-17.3 individuals/m3 and high values were observed in the northern Antarctic region. Eukrohnia hamata and Sagitta gazellae were distributed widely in the Southern Ocean. S. tasmanica was a dominant species in the Subtropical region. Complicated hydrography in the Subtropical Convergence (STC) and Ant-arctic Convergence (AC) regions was reflected in the distribution of chaetognaths. The occurrence of S. minima in the subsurface layer of the central station of the STC region suggests that the northern warm and saline water mass intruded south-ward into the depths of 30-70 nl. The plural populations of E. hamata exist in the AC and STC regions. Vertically segregative distribution of chaetognaths was ob-served in the Antarctic and AC regions: S. gazellae at the depths of 50 to 150m, E. hamata at 100 to 400 m, and S. maxima at 200 to 500 m. 1