The vertical migration behavior of Trichocoleus sp. in the absence of light

Abstract

Trichocoleus sp. is a blue-green algal species that forms mats in the sandy sediments of Douglas Lake. The alga forms mats in order to gain protection from UV radiation, and the alga sacrifices productivity in the process. Once removed from light and UV exposure, Trichocoleus sp. interestingly did not migrate upward in the sediments to seek higher nutrient concentrations and light levels. A combination of mechanisms such as positive and negative chemotaxis and factors such as shading and anoxic conditions could have influenced the behavior of Trichocoleus sp. in such a way that no change in mat depth was evident at the conclusion of the experiment. The thickness of the mat did increase slightly, however. The function of mat thickness is unclear but might represent mat stability.