Dinoflagellate Cysts in Recent Marine Sediments from Tasmania, Australia

Abstract

Thirty-four cyst types capable of seeding plankton dinoflagellate populations have been identified in Tasmanianestuarine sediments. The most common cysts were those of <i>Gonyaulax grindleyi, G. spinifera, Gymnodiniumcatenatum, Gyrodinium sp., Polykrikos schwartzii, Protoperidinium conicum, P. pentagonum, P. subinerme,Scrippsiella spp. and Zygabikodiniwn lenticuiatum</i>. Also common were ovoid to spherical <i>Alexandriumtamarense-</i>like cysts, which lack distinctive taxonomic features and mucilaginous covering. These latter cystscould only be identified by incubation experiments, which produced living cells of <i>Scrippsiella </i>(2 spp.),<i>Gyrodinium sp. and Alexandrium cf. excavatum</i>. While Tasmanian dinoflagellate cyst assemblages resemblethose of New South Wales, Australia, and New Zealand, one notable difference is the cyst of the toxicdinoflagellate <i>Gymnodinium catenatum</i> which appears to be confined to south-eastern Tasmania.