54 ALGAE IN PHYTOPLANKTON OF THE UNITED STATES 



Division Euglenophyta 

 Class Euglenophyceae 

 Order Euglenales 

 Family Euglenaceae 

 GENUS EUGLENA Ehrenberg, 1838 (fig. 21) 



MORPHOLOGY 



Cell is elongate, oblong, lanceolate, or spindle shaped; rigidly or 

 spirally twisted; solitary; sometimes attenuate at posterior end; and as 

 much as 450 fim in length. Each cell contains a single flagellum. A cell 

 has a gullet at the anterior end and one or more contractile vacuoles ad- 

 joining a flask-shaped reservoir. Eyespot is generally present. 

 Chromatophores are numerous and discoid to band shaped. 



REPRODUCTION 



Reproduction is by longitudinal division of the cell beginning at the 

 anterior end. Occasionally, a cell becomes immobile and surrounded by 

 a gelatinous sheath, following which cell division occurs. This is called a 

 palmelloid colony. 



OCCURRENCE 



Euglena is of widespread distribution mostly in the tychoplankton. It 

 is very indicative of waters rich in organic matter, for example, those 

 below domestic sewage outfalls. It can occur in such abundance as to 

 color the water a deep green (Smith, 1950). Occasionally, the light- 

 induced production of haematochrome in abundant cells will color a 

 body of water brick red (Prescott, 1962). 



ENVIRONMENTAL CONDITIONS 



Standard 

 Range Mean deviation 



Temperature degrees Celsius 0.0 - 



pH 4.1 - 



Dissolved oxygen milligrams per liter .1 - 



Specific conductance micromho 10 



Total alkalinity milligrams per liter 



Total hardness do 3 



Total nitrogen do .01- 



Total phosphorus do .0 - 



SPECIES INFORMATION 



Refer to Johnson (1944) and Prescott (1962). 



