Document Type


Date of Award



Calothrix parientina, Gloeotrichia echinulata, Algae, Conesus Lake Algae (group), Calothrix parietina (Nageli), Thuret

Degree Name

Doctor of Philosophy (PhD)


Geological Sciences

First Advisor

George J. Schumacher

Second Advisor

Jacob H. Fischthal

Third Advisor

Herman S. Forest


Drouet (1973) on a morphological basis and the present author in his laboratory and field studies on the life gyre (cycle) and developmental morphology have shown that Gloeotrichia echinulata (J.E. Smith) Richter and Calothrix parietina (Nägeli) Thuret are the same species. According to International Code of Botanical Nomenclature (1972), C. parietina takes taxonomic priority.

In this alga, the akinetes (spores) are not the major means of over-wintering. Short hormogones and filaments of the form known as C. parietina are actually the common winter forms.

There is a direct relationship between different temperatures (10, 15, 21° C) and the frequency of akinete formation over a 2 to 3 week period in that more are produced as temperatures increase. Akinetes germinated in increasing percentages up to 2 weeks following maturation. Germination decreases from this point to senescence at about 7 weeks. Once senescence was reached, change of medium or temperature could not induce germination.

Three kinds of akinete germlings were observed: tapered trichomes, hormogones, and undivided germlings. The phenomenon of germling release as tapered trichomes has been recorded for the first time in blue-green algae.

Colony formation is attributed chiefly to hormogonial production and clumping followed by differentiation. Increase of colony number to bloom concentration is achieved by hormogonial production, and also splitting or budding of the larger colonies into smaller colonies.