72 ALGAE IN PHYTOPLANKTON OF THE UNITED STATES 



Division Chrysophyta 

 Class Chrysophyceae 

 Order Chrysomonadales 

 Family Ochromonadaceae 

 GENUS DINOBRYON Ehrenberg, 1835 (fig. 30) 



MORPHOLOGY 



Cells are free floating, sessile, or ephiphytic and may be solitary or in 

 colonies. They are enclosed in conical, campanulate, or cylindrical 

 cellulose lorica, which have smooth or undulate walls, pointed bases, 

 and open tops. Colonies may be arbuscular, divergent, or compact. The 

 conical or ovoid protoplast is attached to the base or side of the lorica 

 and contains 2 flagella of unequal length. Each cell has 1 to 2 elongate, 

 parietal, golden-brown chromatophores, several contractile vacuoles, 

 and 1 apical eyespot. 



REPRODUCTION 



Longitudinal division of a cell results in 2 daughter cells, which 

 become attached to the mouth of the parent-cell lorica. New lorica are 

 formed. Pascher (1943) observed both palmelloid stages and 

 statospores. 



OCCURRENCE 



Dinobryon is widely distributed and generally is indicative of hard 

 waters. It commonly is intermingled with other algae in pools and dit- 

 ches (Smith, 1950). 



ENVIRONMENTAL CONDITIONS 



Standard 

 Range Mean deviation 



Temperature degrees Celsius 0.0 - 33.5 



pH 4.1 - 9.0 



Dissolved oxygen milligrams per liter .7 - 14.7 



Specific conductance micromho 11 -7,700 



Total alkalinity milligrams per liter - 477 



Total hardness do 5 -1,700 



Total nitrogen do .00- 12.0 



Total phospnorus do .0- 2.1 



SPECIES INFORMATION 



Refer to Ahlstrom (1937). 



