44 



ALGAE IN PHYTOPLANKTON OF THE UNITED STATES 



Division Chlorophyta 

 Class Chlorophyceae 

 Order Chlorococcales 

 Family Characiaceae 

 GENUS SCHROEDERIA Lemmermann, 1899 (fig. 16) 



MORPHOLOGY 



Solitary cells are acicular to fusiform and are straight or slightly 

 curved. Cell apices are tapered into setae; one may be bifurcate. Total 

 cell length, including setae, may exceed 150 /mi. The single 

 chromatophore is H -shaped. Eyespot may or may not be present. 



REPRODUCTION 



Biflagellate zoospores (4 or 8) form within the cell and are released by 

 transverse splitting of the parent-cell wall. The zoospore loses its 

 flagella and develops into a vegetative cell. 



OCCURRENCE 



The solitary, free-floating cells of the genus are found in the 

 euplankton. 



ENVIRONMENTAL CONDITIONS 



Range 



Mean 



Standard 



deviation 



Temperature degrees Celsius 0.0 



pH 5.3 



Dissolved oxygen milligrams per liter .1 



Specific conductance micromho 10 



Total alkalinity milligrams per liter__ 



Total hardness do 6 



Total nitrogen do 00 



Total phosphorus do .0 



SPECIES INFORMATION 



Refer to Smith (1920, 1926) and Prescott (1962). 



