Shell Colour in Cercozoa; a Simple Trait to Distinguish Thecofilosea from Imbricatea?

Abstract

Rigid and persistent shells of microeukaryotes are widely used as bioindicators in ecological and paleontological studies. Drawing conclusions on ecological or evolutionary patterns depends strongly on the right taxonomic assignment of the observed species, however confusion is common. Especially in filose shelled amoebae it is often unclear whether species belong to the Imbricatea or Thecofilosea when only morphological data are collected. Molecular surveys shed light on their evolutionary relationship; based on these we propose a hypothesis how to differentiate doubtful species even light microscopically.

Keywords: Testate amoebae; morphological identification; morphological traits.; organic cement; shell evolution; thecate amoebae.