124 ALGAE IN PHYTOPLANKTON OF THE UNITED STATES 



Division Cyanophyta 

 Class Cyanophyceae 

 Order Hormogonales 

 Family Oscillatoriaceae 

 GENUS OSCILLATORIA Vaucher, 1803 (fig. 56) 



MORPHOLOGY 



Cells are discoidal and adjoined at the flat surfaces into long 

 trichomes. Trichomes are unbranched, uniseriate, and sometimes 

 apically attenuated. Sheaths are not evident. Filaments are straight, 

 curved, or contorted and may be solitary or in floccose masses. They 

 are free floating or epiphytic. Heterocysts and akinetes are lacking. 



REPRODUCTION 



Reproduction is by hormogonia. 



OCCURRENCE 



Oscillatoria is one of the most ubiquitous of the algal genera. It is 

 widely distributed in all types of waters and is found commonly in the 

 euplankton, tychoplankton, and periphyton. 



ENVIRONMENTAL CONDITIONS 



Standard 

 Range Mean deviation 



Temperature degrees Celsius 0.0 



pH 3.4 



Dissolved oxygen milligrams per liter .1 



Specific conductance micromho 10 



Total alkalinity milligrams per liter 



Total hardness do 3 



Total nitrogen do .00 



Total phosphorus do : .0 



SPECIES INFORMATION 



Refer to Gomont (1892a, b) and Prescott (1962). 



