Other
desmids also were described having apical concavity as Vincularia roraimae K.
Group Jan Feb Mar Apr May Jun Jul Aug Sep Ga 7.6 52.3 38.3 36.1 29.5 52.5 63.3 38.4 36.6 Bga 17.6 8.5 7.9 16.3 16.3 6 3 15.6 8.1 Dia 62.8 15.8 26.9 17 18.6 16.6 18.1 19 31.8 Des 3 9.3 7.3 11.5 20.5 12.9 6.5 9.3 8.8 Pro 0.3 1.5 4.2 5.9 4.4 1.1 0 4.2 3.5 Cru 0 0.8 0.7 0.2 0 0 0 0 0.2 Rot 0 0 0.9 0.2 0 0 0 0 0 Ins 0.1 0.2 5.1 0.1 0.7 0.9 0.5 0.3 0 Mis 8.6 11.6 8.7 12.9 10 10 8.6 13.1 11 Group Oct Nov Dec Average Ga 48 48.9 14 36.5 Bga 10 10.1 27.1 12.8 Dia 3.3 11 44.5 25.4 Des 28.6 12.9 6.1 11 Pro 2.1 4.9 2.2 3.2 Cru 0 1.4 0 0.3 Rot 0 0.1 0 0.1 Ins 0 1.8 0.1 1.1 Mis 7.9 8.9 5.9 9.7 ga: green algae; bga: blue-green algae; dia: diatom; des:
desmids; pro: protozoa; cru: crustacean; rot: rotifer; ins: insect; mis: miscellaneous.
The most important factor towards a correct taxonomical identification of algae is the careful detailed knowledge of its morphological variability, much more when
desmids are concerned since the species concept in the group is presently so very bad defined (Kouwets, 2008).
Botos Lake was dominated by dinoflagelates (Hargraves & Viquez 1981, Umana 2001), Chato Lake was dominated by
desmids (Arthodesmus bifidus) and Cryptophyta was not found in the samples (Umana & Jimenez 1995).
Among the Chlorophyta, the
desmids were the most diverse, accounting for 52% of the taxa of this division.
(2007) studied the Paraibuna and Pomba River and recorded a dominance of diatoms and
desmids in the biovolume in the middle and downstream stretch of Pomba River.