Biota of Lakes and Reservoirs - Hydro-Environmental Analysis: Freshwater Environments - page 418

to the basic taxonomic rank, the species. The classiication may be illustrated by that for the
Paramecium :

• Domain Eukaryotic

• Kingdom Animalia

• Phylum Ciliophora

• Class Ciliatea

• Order Hymenostomatida

• Family Parameciidae

• Genus Paramecium

• Species aurelia , bursaria , and caudatum

All living organisms may be subdivided into three domains, the eukaryotes, which basically
have a cell nucleus, and those that do not (the prokaryotes), which include bacteria and archaea. The
domains are further subdivided into kingdoms. The kingdoms under Eukaryota include Animalia
(all animals), Plantae (all plants), Protista (algae and protozoans; Figure 15.7), etc. So, for example,
Animalia or the other kingdoms represents a vast and diverse assemblage of organisms that shares
some common characteristics.
Now, to revisit the phytoplankton, the general groups mentioned at the beginning of this section
were the blue-green algae, green algae, brown algae, and diatoms. The taxonomy of these groups is
listed next. As indicated, blue-green “algae,” or Cyanobacteria, are in a separate domain from the
true algae and they are autotrophic bacteria. The “green” algae, “brown” algae, and diatoms are all
eukaryotes and are representatives of separate divisions within the kingdom Protista.

• Domain Bacteria (prokaryotic)

• Kingdom Monera

•

Division Cyanobacteria

• Domain Eukarya (eukaryotic)

Animals

True plants

True fungi

One-celled plants
and animals: protozoa
and algae

Bacteria and
blue-green
algae

FIGURE 15.7 Family tree. (The organization is diagrammatic and may not relect evolutionary associa-
tions, which are frequently updated and revised; Prepared by Robert G. Howells, Texas Parks and Wildlife
Department, Ingram, Texas, 2003. Courtesy of the Texas Parks and Wildlife Department © 2003. With
permission.)