Aragon > Naturräume in Aragon > Fauna
Protozoa are the simplest animals since they are made up of a single cell.
Therefore, they are unicellular organisms. Through their single cell they perform all vital functions.
Protozoa are very abundant and are found in all places on earth, especially, in humid places. They are frequently parasites on animals, plants and on man, and can cause diseases.
There are about 50,000 species of protozoa and they can live isolated or forming colonies.
Respiration is carried out through the cell membrane and by the water particles absorbed with the food.
The expulsion of carbon dioxide is done through pulsatile vesicles or vacuoles.
When the pulsatile vacuole is filled with water, it opens and releases it to the outside.
Protozoa move in various ways. The ciliates, like Paramecium, do it through the rhythmic and rapid movement of the cilia.
Other protozoa move through the rapid movement of the flagellum or pseudopods.
Feeding is usually done by capturing food that enters the cytoplasm through an opening in the membrane.
Nutrient vacuoles are formed in the cytoplasm and waste is expelled by fecal vacuoles.
The paramecium sucks the food producing a vortex with the cilia.
Amoebas trap food by surrounding it with the pseudopods they form.
Protozoa can reproduce by bipartition (division in two), by budding (growth of a bud or daughter cell) and by sporulation (fragmentation of the mother cell into spores). When the latter occurs, they can remain embedded in a capsule for a long time.
The flagellate protozoa or mastigophores are provided with one or more flagella that allow them to move.
They are unicellular, they reproduce by longitudinal division (lengthwise); they live freely and many are parasites that cause diseases, some very serious, especially trichomoniasis, sleeping sickness, Chagas disease, leptomoniasis, etc.
The class of flagellates includes the phytoflagellates or dinoilagelates , which are treated in the Plant Kingdom (unicellular algae).
Trypanosome is the cause of sleeping sickness, and it is transmitted by the tsetse fly. The fly, when biting an infected man, sucks some trypanosomes that multiply in his intestine. Then, when it bites again, it injects the protozoa that reproduce and invade the brain.
Cause of various diseases, in the mouth, intestine, vagina. etc.
It is the most numerous class of protozoa.
They have cilia in the membrane that they use to move around.
Others have cirrus-like legs.
Many are free, swimmers and others live attached by peduncles that can be wound like a spring.
They live in fresh or marine waters.
Some are parasites in mammalian fish and even in man.
In dry periods they can become encyst.
Among others, Paramecium, Vorticella Stentor, Stilonichia, Balantidium, Mesodinium, etc. can be mentioned.
They only present cilia in their juvenile stage. As adults they are attached to the substrate by means of a peduncle and have hollow tentacles with suction cups, with which they grasp their victims and suck their juices.
These protozoa have pseudopods or extensions like feet, to move and catch food.
Some, like the Ameboids, do not have a rigid membrane; others, foraminifera, radiolarians and heliozoans have a siliceous or calcareous skeleton and their pseudopods are radiant in an infinite number of shapes and patterns.
They exist in immense quantities in seas and rivers, forming an important part of plankton.
A small list of species in Aragon would be the following:
Vertebrates | Invertebrates |
---|---|
MammalsBirdsReptilesAmphibiansFishes |
MetazoansProtozoa |
images about the fauna in Aragon. photographs on invertebrates. beneficial animals for agriculture. |