Re: What color is euglena, amoeba, paramecium?

Hello Lindsey!

Euglena, Paremecium, and amoebae are all examples of single-celled protists.  
The protists are an extremely diverse group of mostly small unicellular 
organisms, although the large seaweeds and kelps are also protists. 

Euglena is a single-celled green alga.  It has chloroplasts, and thus a 
green color.  Euglena also has a reddish eyespot, which it uses to detect 
the appropriate light intensity to enhance photosynthesis.  However, Euglena 
is not solely autotrophic - under low light conditions, it can live as a 
heterotroph, absorbing dissolved organic matter (DOM) from the environment.  
In fact, there are some close relatives of Euglena that lack chloroplasts 
and thus are not photosynthetic.  But Euglena itself is green. Here's a link 
to a video of a single Euglena cell smooshing around under a microscope; you 
can see the green chloroplasts and the red eyespot:  http://
micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/euglena/rostrifera/56k/
rostrifera02.html 

The amoebae are themselves a very diverse group of unicells.  There are many 
kinds of amoebae, but they all use pseudopodia ("false feet") to move over 
surfaces.  The standard naked amoeba, which you might have seen in the 
laboratory,  is a fairly colorless cell.  Under phase-contrast light 
microscopy, it might be a pale bluish-gray color, but they don't have much 
pigmentation.  This link will take you to a video of an amoeba engulfing a 
food particle: http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/
amoeba/56k/amoeba05.html

Some amoebae have shells or skeletons.  The foraminiferans (forams) have a 
calcium carbonate shell that resembles a snail's shell.  The shell is opaque 
and whitish, although the cell itself is colorless.  Radiolarians and 
acantharians have beautiful skeletons of transparent glass-like rods.  
Again, the cell and the skeleton are mostly colorless.  Here's a photo of 
radiolarian skeletons: http://micro.magnet.fsu.edu/primer/techniques/
phasegallery/radiolarians.html

Paramecium is a ciliate.  It is non-photosynthetic, and thus has no 
chloroplasts.  Paramecium cells are mostly colorless, and in terms of color 
resemble amoeba cells.  You can see for yourself:  http://
micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/paramecium/t1/
paramecium04.html  

Allison J. Gong
Mad Scientist