is it and where does it live? This
centric diatom’s cells are drum-shaped, the valve diameter and the density of marginal striae are highly
variable. Cyclotella meneghinianais a rather cosmopolitan
species; in tropical freshwaters,it is associated with various
water depths and salinity1, and, in temperate regions, it is a
typical planktonic taxon in the late summer-autumn2. In North America, this species can cope with a wide range of conditions, for
example from freshwater to saline waters in the Great Plains lakes3.
are we studying it? Studying the distribution of this and other
diatoms in thousands-of-years old sediment and ice cores, paleoecologists - nature’s ‘archaeologists’ - can infer past
salinity, pollution, eutrophication and climatic changes4. Moreover,
analyzing water, soil and vegetation…
is it? The genus Gomphonema includes numerous species growing on mucilaginous stalks. These
diatoms are asymmetrical biraphid, as the bottom
part is usually longer and thinner than the top part and they have two raphes, narrow
slits that allow them to move over surfaces. Yes, there are diatoms that perform photosynthesis, move
and even eat
organic matter! G.
parvulum is on the lower end of the size spectrum for the genus (length
from 15 to over 100 µm and width between 5 and 15 µm).
does it live? In North America, species of Gomphonema can be found in
many habitat types in lakes and streams with pH close to 7. Gomphonemaparvulum is widespread and tends to live in
freshwater with high nutrient concentrat…