Dinoflagellates in the Australian Region.

Abstract

In this paper, the taxonomy of the dinoflagellates found in Australian waters is given, and the species concept as applied to the group is discussed. It is suggested that the Linnaean species concept cannot be strictly applied to a group which has, as a whole, no known sexual process and of which the vast majority of forms has not been cultivated. The seasonal variation and fluctuations of dinoflagellates in Australian waters are considered. It is found that, as usual, the greatest number of species occurs in warmer waters. Dinoflagellates are regarded as excellent indicators of water masses, and in one example, i.e. west of Tasmania, subtropical dinoflagellates led to the postulation of a subtropical current flowing east from Cape Leeuwin to King I. This has recently been confirmed by the finding of warm-water turtles on the west coast of Tasmania. Dinoflagellates are not as important as diatoms or tropical blue-green algae in productivity, except on rare occasions, but do serve as food for certain groups, e.g. salps, tintinnids, etc. Some are halophytic, some holozoic, and some facultative. No single factor or set of factors can be adduced to explain dinoflagellate maxima. There is some evidence of a rhythm, which may be tidal, in Goniaulas digitale and also in G. catenella.