Background:

Cantera Oriente houses a diverse microalgal component. The lentic ecosystems have received much grea ter attention than the lotic systems, which makes their study important.

Goals:

Compare cyanoprokaryotic communities found in a natural and an artificial lotic environment. To measure the relative density and frequency of species and to mea sure their association with environmental factors.

Methods:

Filamentous chlorophytes, wood, and roots of submerged plants were sampled once a month in two lotic environments (natural and artificial) from September 2012 to September 2013, to study the epiphytic cyanoprokaryotes. Simultaneously, physical and chemical data were obtained with field mea surements and laboratory analysis. Species were evaluated according to the Importance Value Index (IVI).

Results:

Only 31% of cyanoprokaryotes were shared by both sites. The chemical and physical data showed equal variances and were not correlated with IVI values, denoting a low level of environmental disturbance. The proportional statistical comparison of the observed and theoretical IVI of the species of each environment, (Chi square), established that the cyanoprokaryo tes were associated with the type of environment, the type of substrate, and the climatic season.

Conclusions:

The lotic environments in Cantera Oriente are characterized by a low level of disturbance, which does not affect the presence or biomass of the cyanoprokaryotes and the Importance Value Index is associated with the type of environment and substra te as a site of colonization, which seems to explain the habitat preferences of some species.