Re: Why do some amoebas seem to have 2 or more nuclei?

Amoebae are uninuclear organisms, that  is, they  have a single  nucleus. 
The trophozoites of these protozoans  divide by binary fission,where  the  
organism  divides  in two  and  produces  2  exact daughter cells. In the 
case of  amoebae,  this  cellular  division starts  with  the  nucleus:  
the  mother  nucleus  divides  into  2  daughter  nuclei and  once this  
is  done, the  cytoplasm of  the cell  divides. So  when   a  amebic  
trophozoite with 2 nuclei  is  observed ,  it  is  actually  undergoing  
asexual  reproduction through  binary  fission.

The cyst  forms  of  amoebae are also  multinucleate. Again , this  is  
achieved by  multiple  divisions  of  the nucleus. The  number  of  
nuclei  observed in  the cyst  form, as well  as their morphology and 
size,  can be used  as markers  for  identiofying some of  the   species  
of  Amoeba that  infect  man. Thus,  _Entamoeba histolytica_  cysts  can  
have  4 nuclei, whereas  _Entamoeba  coli_  will  have 8  or  more nuclei.
 
 
http://www.dpd.cdc.gov/dpdx/HTML/Amebiasis.htm


http://www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Amebiasis_il.htm


http://hna.ffh.vic.gov.au/phb/hprot/idci/am.html


http://homepages.uel.ac.uk/d.p.humber/powerpoint/amoebiasis/ 
 

http://homepages.uel.ac.uk/D.P.Humber/powerpoint/amoebiasis/sld001.htm

[Amoebae of the genus Pelomyxa
can have over 1000 nuclei. - Moderator]