Logo Universitat Bremen

Impagidinium plicatum

Zonneveld, K.A.F. and Pospelova V. (2015). A determination key for modern dinoflagellate cysts. Palynology 39 (3), 387- 407.

 
dorsal-antapical view
photo: Karin Zonneveld
locality: Gulf of Taranto (Eastern Mediterranean)
cross section
photo: Karin Zonneveld
ventral - apical view
photo: Karin Zonneveld

Field Characteristics

Impagidinium plicatum Versteegh et Zevenboom 1995

Field characteristics:
Proximochorate cyst of ovoid to elongate shape. Tabulation is well expressed by crenulate sutural septa except in the sulcal area where they are generally absent. The sutural septum between plate 1”' and the sulcus is also absent. Septa between 1'/4', sulcus/1p, sulcus/6'', 1''/1c, 1c/2'' and 6c/6''' can be lacking as well. Archeopyle is precingular (type P).

Dimensions: Cyst body: 28 x 38 µm; height of septa: 2 to 4 µm.
Motile affinity: Probably a cyst of Gonyaulax spp.
Stratigraphic range: Earliest Zanclean to Recent.

Comparison with other species:
Very characteristic for this species are the curling septa. The tabulation can be almost completely reflected but this can vary (see characteristics for septa that might not be there). It is a relatively small cyst compared to the other Impagidiniums.

Geographic Distribution

Geographic distribution based on :
Zonneveld et al., 2013. Atlas of modern dinoflagellate cyst distribution based on 2405 datapoints. Review of Palaeobotany and Palynology, v. 191, 1-197
Impagidinium plicatum has a temperate to equatorial distribution. Although it can be observed in shallow-coastal sites it is usually found in oligotrophic/mesotrophic environments with low upper water productivity such can be found in the central parts of the oceans. It distribution is restricted to full-marine environments that are characterized by well ventilated bottom waters.
Distribution:
Impagidinium plicatum is restricted to temperate to equatorial full-marine regions between the sub-tropical frontal systems of both hemispheres although there are a few recordings from the Beaufort Sea, the Bering Sea and near Antarctica. Although it can be observed in coastal sites, highest abundances (up to 20%) occur in the offshore eastern Pacific.

Environmental parameters:
SST: 0 - 29.6°C (winter - summer) and SST > 8.0°C in summer. Exception is formed by few sites from the Beaufort Sea, the Bering Sea and Pacific Sector of the Antarctic Circumpolar Current where SST winter lies between -2.0 - -0.3°C. SSS: 30.3 - 39.3 (summer - autumn) with exception of the Antarctic site where SSS: 26.2 (summer), [P]: 0.06 - 1.07 μmol/l, [N]: 0.04 - 8.8 μmol/l, chlorophyll-a: 0.05 - 2.1 ml/l, bottom water [O2]: > 0.8 ml/l.
Abundances of > 10% occur at temperatures between 12.0 - 25.2°C (winter - summer). With exception of a Bering Sea site, I. patulum occurs in oligotrophic to mesotrophic regions with low upper water bioproductivity and well ventilated bottom waters.

Comparison with other records:
Impagidinium plicatum has not been recorded from regions not covered by this Atlas.