THE TYPOLOGY OF VERTICAL-DISTRIBUTION OF OCEANIC ZOOPLANKTON

The study is aimed at typological analysis of vertical distribution of different taxa and taxocenes formed by zooplankton in habited differe nt layers of pelagic zone. The basic of typololgy is provided by the t heory of zooplankton vertical distribution proposed by Rudjakov (1986) . It was shown that three phases of the population distribution during vertical migration, i. e. the positive asymmetrical in the upper part , the disperse (closed to a normal) in the middle phase of periodical vertical movements, and the negative asymmetrical near the lower limit s of the range' have the analogies among tipes of vertical distributio n caracteristic of some taxa and taxones of pelagic animals. The posit ive asymmetrical distribution with maximum in feeding zone is treated as archaetype. Its derivates are normal dispersionale type (middle dep th or submersing) and inversely (negative) asymmetrical (submerged) ty pes of distribution. Archaetypic distribution is peculiar to the taxa of order-type rank and to the layer 0-1000 (2000) m of pelagic zone. A s to the taxa of the genus-family rank, especially specialazed ones an d to the majority of the deepsea groups the normal distribution could be usually expected. Inversely asymmetrical (submerged) distribution m ay be characteristic of near-botton fauna. The relations of the types of distributions to the feeding habits, taxonomic rank of groups and p ossible mechanism of speciation in the pelagial are discussed.