There are various Protozoans found on this planet most are harmful, while a few has great economic importance. This slide presents about the economic importance of few Protozoans.

1. A Seminar report on
The Economic importance of
protozoa
By Abhishek Giri
M.Sc. (part-I)
Roll no. 1326056
Paper – I , Unit - II

2. A presentation on
The Economic importance of
protozoa

4. What are Protozoan?
• Protozoa means “first animals,” and are described as unicellular
eukaryotes (Goldfuss, 1818).
• They are microscopic found in fresh, marine waters & damp soil.
• A protozoan might be Defined as an Organism which is made
up of a mass of protoplasm not divided into cells and which
carries on all vital activities of life.
• Protozoan are either solitary or colonial.

5. Economic importance of protozoa

6. INTRODUCTION
o Protozoan are Ubiquitous.
o They live as commensals & parasites in animals &
plants.
o Man is invariably effected by them.
o Some of them are beneficial , while most of them are
harmful to man
o Domestic animals are also affected.

7. A. Beneficial protozoa
• Some protozoa are of great importance for man kind and other
animals
• They can be classified into following categories:

8. 1] Helpful in Sanitation
o Protozoan play an important role in sanitary betterment &
improvement in keeping water safe for Drinking purpose.
o Protozoan live in polluted water & feed upon waste organic
substances & thus purify it.
o Some feed on bacteria & purify the water indirectly.

9. 2] Protozoa as Food
o Though microscopic but directly or indirectly provide source of
food to man, fish, & other animals.
o Larvae of aquatic insects feed on aquatic protozoans,
When these larvae of fish, prawns. etc grows to adult becomes
a source of food of man.
o Pelagic protozoan like foraminefera and Radiolaria sink after
death to the bottom of ocean & forms the food of deep sea
fauna.
o Few protozoa have chlorophyll & are capable of synthesizing
own food.

10. foraminiferans
Radiolarian

11. 3] Commensal Protozoa
o These protozoan are those which live on or in the body of other
animals & derive some benefits from the relationship.
o However, the other partner is neither benefited nor injured.
o They may be of two types :-
(i) Ectocommensal Protozoa
(ii) Endocommensal Protozoa

12. (i) Ectocommensal Protozoa
o They live on the surface of the host
body.
o Ciliates & Suctorians lead an
ectocommensal life on molluscs,
arthropods, fishes and frogs, etc.
o The host simply act as a substratum
for these ectocommensals.
Suctorians

13. (ii) Endocommensal Protozoa
• They live inside the body of the hosts.
For example,
a. Trichomonas, Giardia, etc., live as endocommensal within
the alimentary canal of man.
b. Entamoeba coli live as endocommensal in alimentary canal
of frogs.
c. Balantidium coli feed upon harmful bacteria in the colon.
• They feed on bacteria and so have beneficial effect.

14. Trichomonas
Entamoeba coli
Balantidium coli

15. (4) Symbiotic Protozoa
o Those protozoan lives a symbiotic relationship
with other animals.
o In this association, the two partners become
very much dependent on each other that one
cannot get along with other & their separation
results in the death of both.
For example:-
1. Trichonympha & colonympha are intestinal
flagellates present in termites & wood
roaches. They help in the digestion of
cellulose which is converted to glycogen.
the glycogen is then utilized by both.

16. (5) Commercial use of Protozoan skeletons
o Skeleton of dead Foraminfera and Radiolaria sink in sea &
form oceanic ooze. This solidify & covert to rock strata.
For example:-
o Such rock strata are White chalk cliff’s of Dover and
England, and stone beds of paris, Cairo & north America.

17. o Paris building are built of the limestone which is
composed of shells of genus Hiliolina.
o Pyramids of Egypt are constructed by lime-stone deposits
of Nummulite shells.
o Sometimes, skeletal deposits are used as filtering & as
abrasive.

18. 6] Protozoans in soil
o They play an important role in Soil fertility.
o They graze on soil bacteria.
o Protozoan also excrete Nitrogen & Phosphorus.

19. (6) Zoological importance of
Protozoa
o Protozoans are ideal material for Cytological, cytochemical,
physiological, biochemical & genetical studies, because of their
small size, simple organization, quick reproduction & easy
availability.

20. B. Harmful Protozoa
• Almost all harmful Protozoans lead a parasitic mode of life.
• They parasitize almost every plants & animals including man and
various animals.

21. 1] Soil Protozoa
o Several species present in the soil feed upon the nitrifying
bacteria, thus declining their activity & consequently decrease
the amount of nitrogen in the soil.

22. 2] Water pollution
o Wherase some are helpful in sanitation, others are responsible
for water contamination, Protozoan of faecal origin.
o Uroglenopsis – pollute water by producing aromatic oily
secretion with bad odour which is unfit for human consumption.
o CuSO4 is used to kill such protozoans.

23. o Noctiluca & Gymnodinium- sometimes multiply so
extensively that the water becomes red with their
bodies. The phenomena is known as “Blooming” & is
the cause of “red tides”.
o Larger concentration of these leads to destruction of
fish & even poisoning of edible molluscs.

24. 3] Pathogenic Protozoa
• Disease producing protozoans are termed as pathogenic
protozoa.
• More than 25 different species of parasitic protozoa live in
man alone.

25. 4] Parasitic Protozoa
o Parasitic protozoans live on or within the body of other
organisms for sake of food, shelter and continuance of
race.
o The parasite can be classified into two categories on their
occurrence.
1) Ectoparasitic Protozoa :
2) Endoparasitic Protozoa:

26. 1] Ectoparasitic Protozoa
o They live on the external surface of the host plant or anmal.
o Less common.
For example:-
1. Hydramoeba hydroxena : ectoparasite of Hydra & feeds on
ectodermal cells.
2. Ichthyophthirius multifiliis: ectoparasite of fresh water fishes
causes integumentary blisters.
3. Leishmania tropica: ectoparasite of man causes oriental
sores.

27. Hydramoeba hydroxena
Leishmania tropica
Ichthyophthirius multifiliis

28. 2] Endoparasitic Protozoa
• They live inside the body of the host plant or anmal.
• more common
Further classified into according to their location in the host body.
i) Coelozoic protozoa : living in the body cavity or coelome e.g
Entamoeba,Trichomonas, Balantidium, etc.
ii) Histozoic Protozoa : living between the cells of tissues and
body organs e.g., Giardia, Eimeria,, etc.
iii) Cytozoic Protozoa : living inside the host’s body e.g.,
plasmodium, leishmania, Haemoproteus, etc.

29. Haemoproteus
Eimeria
Balantidium
Sarcocystis

30. o Endoparasitic pathogenic protozoans are further classified
according to their exact location in the body :-
1) Endoparasite of mouth : Dwells in mouth or buccal cavity.
a. e.g., Entamoeba gingivalis, Trichomonas tenax :
- tartar of teeth & abscesses of gums.
- causes Pyorrhoea
- infection – kissing & feeding in same bowl.
Peridontal disease

31. b. Leishmania brassiliensis :
- dwells in oro-nasal mucous membrane.
- causes espundia.
- infection – biting of sandfly.

32. 2) Endoparasite of digestive tract :
a. e.g.,Entamoeba histolytica :
- inhibits intestine of man.
- causes amoebic dysentery & ulceration of colon.
- infection – ingestion of cyst with food or drinks.

33. b. Giardia intestinalis :
- dwells in large intestine.
- causes diarrhoea.
- infection – ingestion of cyst with food or drinks.

34. 3) Endoparasite of blood : dwells in blood of vertebrate
a) e.g., Tryphanosoma sps :
- blood of man.
- causes Rhodesian sleeping sickness.
- infection – bite of Glossina morsitans.

35. b) Leishmaina sps :
- intracellular, in children.
- causes Espundia, oriental sores.
- infection – bite of sandfly.

36. 4) Endoparasite of Urinogential tract : dwells in
urinogenital organs & causes various pathogenic
disease.
a. e.g., Trichonomas vaginalis :
- urinogenital system of women & men.
- causes annoying itch, abnormal discharge.
- infection – occur directly in coitus.

37. b. Trichonomas foetus :
- urinogenital system of cattle, horses, & sheep.
- causes abortions, delayed conceptions &
inflammation of sacs.
- infection – occur directly in coitus.

38. 3] Other harmful protozoa

39. Reference
 Invertebrate Zoology by E.L.jordan & R.S.verma.
 A textbook on Protozoa by R.L.kotpal.
 Protozoa by Victor Castillo.
 www.britannica.com/.../protozoan/.../Ecological-and-
industrial-importan...
 www.interlinepublishing.com/user-content-detail-
view.php?cid=911
 https://www.mgccc.edu/learning_lab/.../CHAPTER_11