Senckenberg am Meer Wilhelmshaven

German Center for Marine Biodiversity Research (DZMB)

 

Dinophytes are a morphological very diverse group of about 2500 described species.

Whereas the majority of species has a cell wall composed of cellulosic plates, other species have a very delicate cellwall with out cellulosic components. Besides classicl  taxonomic features like shape, size, number and relative location of the plates other features are used, so far neglected.

The presence or absence of chloroplasts is an important physiological feature, constant on species-level – but not on genus-level. All cells observed alive are tested by epifluorescence-microscopy whether they contain chloroplasts or not. More than 500 species have been tested for which the presence or absence of chloroplasts was unknown so far.

Other features relevant for classifying species into genera is apparently the modus of cell division. In some species the cells are shedding their theca during vegetative reproduction whereas in other species daughter cells are each sharing half of the mother theca.

This feature is constant on genus level, but seems to also a good feature to characterise families or even orders (see : SCHWEIKERT & ELBRÄCHTER 2004). In cooperation with other research-groups molecular genetic analyses are used and provide interesting results not only on species- to family-level but also at the rank of orders (see : KREMP et al. 2005). 

Protoperidinium depressum
Protoperidinium depressum, a species
with theca composed by cellulosic
plates and no chloroplasts, the red
spots are oil-dropplets, residues of
the food.
Podolampas bipes
Podolampas bipes, the plates 
of the mother-theca at the
left part of the cell are distri-
buted to both daughter-cells.

 

   Erythropsidinium agile
Erythropsidinium agile, a
highly dirived dinoflagellate
with an eye-like 
organelle, developed from
a former chloroplast
   
   
 

 

 

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