Clear Concept of Protozoa fish

PROTOZOA

WHAT IS PROTOZOAGr.; Protos: first//Zoon: Animal

Heterogeneous Grouping Of Single-Celled Organism.

Protozoa are those animals which consists of single cell that maybe simple. They are microscopic in size. They displays all types ofsymmetry great range of structural complexity and adaptation forall types of environmental conditions. Their evolution parallels thatof multicellular animals and their origin is perhaps polyphyletic.Infact they are microscopic and acellular animalcules ,withouttissues and organs, having one or more nuclei but no nucleus everin charge of specialized part of cytoplasm. They exist either singleor in colonies.

CHARACTERS OF PROTOZOA

• Small, Microscopic Animalcules, Ordinarilynot visible without microscope.

• Simples & Most primitive of all animals withprotoplasmic grade of organization.

• Body Unicellular. Containing one or moreNuclei which are Monomorphic or Dimorphic.

• Solitary or Forming loose colonies in whichindividuals remain alike and independent.


• Body symmetry none , bilateral , radial orspherical.

• Body naked or bounded by a Pellicle and oftenprovided with simple shells or exoskeletons.

• Body form usually constant varied in some whilechanging with environment or age in many.

• The single cell body performs all essential and vitalactivities, which characterized the animal body.


• Locomotor organelles are finger likepseudopodia or whip like flagella or hair likecilia or absent.

• Nutrition holozoic (animal like), holophytic(plant like), Saprozoic or Parasitic. Digestionoccurs intracellularly inside food vacuoles.

• Respiration & Excretion through generalsurface or through contractile vacuoles whichserves mainly for osmoregulation.


• Reproduction asexual by binary or multiplefission and budding and sexual by conjugationof adults (Hologamy) or by fusion of gametes(syngamy)

• Life history often complicated with alternationof asexual and sexual phases.


• Encystment commonly occurs to help indispersal as well as to resist unfavorableconditions of food, temperature and moisture.

• Free living Protozoa mostly aquatic, inhabitingfresh and sea waters and damp places.Parasitic and commensal Protozoa live over orinside the bodies of animals and plants.Sufficient moistures essential in theirenvironment.


• The single celled individual not differentiatedinto somatoplasm & germplasm. Therefore ,exempt from natural death which is the pricepaid for the body.

CLASSIFICATION

Phylum: PROTOZOA

Sub Phylum: Plasmodroma

Mastigophora Sarcodina Sporozoa Opalinata

Sub Phylum: Ciliophora

Ciliata

CLASSIFICATION BY Hyman (1940),Hickman(1961)& Storer (1965)

Plasmodroma

• Simple and primitive

• Locomotion by pseudopodia, flagella or none. Cilia absent.

• Nucleus reproduction by syngamy

• Asexual reproduction by binary or multiple fusion.

• Life cycle may include an alternation of generations.

Ciliophora

• More complex

• Cilia or sucking tentacles present in at least one stage of life cycle.

• Usually two types of nuclei.

• Sexual reproduction by conjugation.

• Asexual reproduction by binary fusion and budding.

• No alternation of generations

CLASS: SARCODINA

• Body naked or with internal shells or externaltests.

• With Pseudopodia for locomotion & foodcapture.

• Amoeboid during most of life cycle.

• No spore formation, no Conjugation.

• Mostly free living.

Amoeba

Globigerina

Euglypha

Lithocircus

Entamoeba

CLASS: MASTIGOPHORA

• Body covered by thin Pellicle or test of Cellulose,Chitin or Silica.

• One to many flagella for locomotion & foodcapture, some with Pseudopodia.

• Nutrition Autotrophic, Heterotrophic orMixotrophic.

• Asexual Reproduction or by Longitudinal fission.

• No spore formation .No Conjugation.

• Free living or Parasitic.

Chrysamoeba

Chrysamoeba

Dinobryon

Euglena

Volvox

CLASS: OPALINATA

• Body uniformly covered by cilia-like flagella inoblique rows.

• Cytostome absent, Nutrition Saprozoic.

• Nucleus 2 to many , monomorphic or identical.

• Reproduction by binary fission or by gameteconjugation.

• Endo parasites in cold blooded vertebrates.

CLASS: SPOROZOA

• Body covered with a thick pellicle.

• No locomotory organ , mouth and contractilevacuoles are present.

• Nutrition Saprozoic.

• Asexual reproduction by multiple fission.

• Sexual reproduction by spore formation.

• Life cycle complex . All internal parasites.

Myxidium

Nosema

Plasmodium

Sareocystis

CLASS: CILIATA

• Complex Protozoa with a firm pellicle.

• Locomotory organelles cilia or suckingtentacles , in at least one stage of life cycle.

• Nuclei of 2 kind. (dimorphic)

• Nutrition holozoic.

• Asexual reproduction by binary fission.

• Sexual reproduction by conjugation and autogamy.

Balantidium

Paramecium

Opalina

Stentor

BODY STRUCTURE In Protozoa cytoplasm remain separated fromexternal environment by a cell envelope. Thisis of special importance as this coveringprotects the body from harmful influences ofexternal environment, permits a controlledexchange of substances across it, perceivesmechanical and chemical stimuli andestablishes contact with other cells.

BODY COVERING

•Plasmalemma

•Pellicle

Plasmalemma

In some forms, like Amoeba, Chrysamoebaand Saprozoa body covering is a thin plasmamembrane or Plasmalemma.

It posses the typical bilayered lipid & protienultra structure in general. Flexibility of thismembrane allows change in shape. In Amoeba, it is provided with longitudinal ridges ofmucopolysaccharides which help in adhesionto substratum.

Pellicle

In other Protozoa, Euglena, the body coveringis in the form of a differentiated pellicle, whichis some what thicker and firm. It is underlinedby plasma membrane and is formed ofproteins . The rigidity of pellicle gives definiteshape to the body. The thickened pellicle insome of the more specialized Protozoa isvariously ridge and sculptured as inParamecium , Coleps ect.

SKELETONS•Cyst

•Theca

•Lorica

•Shell or test

In Different groups ofprotozoa, various kinds ofpermanent non livingexternal or internal layersare secreted. These may becomposed of organic andinorganic materials, whichare often impregnated withforeign bodies. Theseconstitute the protozoanskeleton.

Cyst

It is temporary sheath and its formed both infree living and parasitic Protozoa when theypass into a dormant state. Exhaustions of foodsupply , drought and putrefaction favourEncystment.

Theca

Many dinoflagellates bear a coat of closelyfitted armour of cellulose, called Theca. Insome forms, theca is composed of two valveswhile in a majority of dinoflagellates it isdifferentiated into a number of plates laid outin a definite pattern and variously sculpturedor ornamented.

Lorica

It is a covering which fits less closely to theorganism than theca. It may be gelatinous ortectinous . It is usually a cup or vase like structurewith an opening, through which emerges theanterior part of organism’s body or itsappendages. Base of Lorica in sessile species maybe attached directly to the substratum ( Phacus,Salpinogoeca) or may end in astalk (Monosiga).Incolonial Loricated individuals,one lorica may beattached to another directly or by means of stalk(Poteriodendron)

Shell or Test

Shells or test are widespread among protozoa.These are coverings in loose contact with thebody , provided with one or more openingsthrough which the animal can protrude itself.

• In shelled amoeba like Arcella and alliedforms, the shell is thin and made up of achitinous material called tectin orpseudochitin ( proteins+carbohydrates).

• In Difflugia and others shell are formed of sandparticles & other substances like pieces ofForaminiferan shells and sponge spiculeswhich are embedded in secreted matrix actingas cement.

• Siliceous shells , made up of silica are found insome Rhizopoda (euglypha).

• Foraminiferan secrete mostly a calcareousshell. Made of calcium carbonate .It may besingled chambered or multi chambered anddimorphic in some cases (elphidium, discorbis)

LOCOMOTION

The ability of an organismto move in a particulardirection

LOCOMOTORY ORGANELLES

• Pseudopodia

• Flagella

• Cilia

• Pellicular Contractile Structures

Pseudopodia

• False FeetTemporary structures formed by streaming flow of cytoplasm

Sarcodina move withthis structures

Pseudopodia

Lobopodia

Filopodia

Reticulopodia

Axopodia

Lobopodia

• Lobe like pseudopodia withbroad and rounded ends.

• Composed of both Ectoplasm& Endoplasm.

Filopodia

• More or less Filamentous pseudopodia

• Composed of Ectoplasm

• Branched & form simple or complex network

Reticulopodia

• Filamentous pseudopodia

• Branched & interconnectedprofusely to form a network.

Axopodia

• Straight pseudopodia

• Radiating from the surface of thebody.

• Contains a central axial rodcovered by granular and adhesivecytoplasm.

Flagella• Thread like projections on cell surface.

• Consists of an elongate, stiff axialfilament, the axoneme , enclosed by anouter sheath.

• Number of Flagella vary in Mastigophorafrom one to eight or more.

• One or two in free living species.

• One to many in parasitic organism.

Cilia

• Highly vibratile small endoplasmicprocess.

• Modified flagella.

• Contains:-- membranous sheath,plasma membrane, enclosed fluidmatrix.

• Characteristics of Ciliata.

Pellicular Contractile Structure

•Pellicle or Ectoplasm called myonemes.

These may be in the form of ridges grooves(euglena) or contractile myofibrils(largerciliates) or microtubules (trypanosoma).

LOCOMOTION METHOD

•Amoeboid Movement

•Flagellar Movement

•Ciliary Movement

•Metabolic Movement

Amoeboid Movement

• Characteristics of Sarcodina and certainMastigophora & Saprozoa.

It consists in the formation of pseudopodia bythe streaming flow of cytoplasm in thedirection of movement.

Locomotion by pseudopodia is possible onlyover a surface.

Flagellar Movement

• Characteristics of Mastigophora

• Flagella need liquid medium for locomotion.

• Three types:

** Paddle Stroke

** Undulating motion

** Simple Conical Gyration

Paddle Stroke

Ulehla and Krijsman (1952)

Common movement of a flagellum is sidewayslash, consisting of an effective down strokewith flagellum held out rigidly, and a relaxedrecovery stroke in which flagellum, stronglycurved is brought forward again.

Undulating Movement

• Wave like undulations.

Tip to Base: forward

Base to tip: backward

Spiral undulations cause the opposite rotaionto the organism.

Simple Conical Gyration

• Butschil’s screw theory postulates a spiralturning of flagellum like a screw.

• This exerts propelling action, pulling theanimal forward through water with

– a spiral rotation

– gyration( revolving in circle) around the axis ofmovement.

Ciliary Movement

• Performed by cilia

• Also need liquid medium for movements.

• The speed of Ciliary locomotion varies from 400 to 2000 microns per second.

Ciliary Movement

Metabolic Movement

• This is typical life of certain flagellates andmost sporozoans at certain stages of their lifecycles.

• Gliding or wriggling or peristaltic movement.

Myonemes

• Gregarine movements

Nutrition

The process by which organisms obtainedenergy (in the form of food) for growth,maintenance and repair.

• Take in food

• Digest food

• Assimilates food

Nutrition in Protozoa

• Protozoa obtain nourishment in many ways.They are:

– Holozoic Nutrition

– Holophytic Nutrition

– Saprophytic or Saprozoic Nutrition

– Parasitic Nutrition

– Coprozoic Nutrition

– Mixotrophic Nutrition

Holozoic Nutrition

• Gr. Holos,whole; zoon, animal.

• Holozoic: completely animal like.

• Depends on ready made solid food particles

• Zootrophic or Heterotrophic Nutrition

Holophytic Nutrition

• Gr. Holos, whole; phyton, plant.

• As typical plant

• By photosynthesis

• Chlorophyll contain chromatophore & Sunlightenergy

• Water & Carbon dioxide.

Saprozoic Nutrition

• Gr. Sapros, rotten ; zoon , animal.

• Depends on organic matter dissolves in themedium

• Parasitic Protozoa, free living flagellates

• Osmotrophy

Pinocytosis

• Ingestion liquid food trough body surface.

• Absorb high molecular compounds.

• Amoeba , certain flagellates Sporozoans andcihates.

Nutrition of Parasites

• Protozoan nourishes themselves partially orwholly

• Rob the food of the host.

• Feed upon its living tissues.

Mixotrophic Nutrition

• Several Protozoa can feed by more than onemethod

• Mixotrophic: mixed type nutrition

• Mesotrophic Nutrition

Coprozoic Nutrition

• Feeding Fecal matter of other organisms

Zootrophic

They depend onready made foodparticles

Don’t depend upon sunlight

Food: proteins

Autotrophic

They are unable to make their own

food using simple substances

Depend on sunlight &

Chlorophyll

Food: chlprophyll

Zootrophic

Digest:Proteins ,Fats ,Starch

Source of Proteins

Autotrophic

Organic food

Source of Nitrogen

Contractile Vacuoles

• Rounded and Pulsating space filled with awatery fluid.

• Exapands (diastole) and Contracts (systole)rhythemically and serves for excretion andosmo regulation.

Food Vacuoles

• Non contractile food vacuoles, smalland large found in the endoplasm.

• Contains water and solid foodparticles.

• Disappear with the egestion of non-digestible food from the body

Water Vacuoles

• Transparent , colorless noncontractile spherical spacesfilled with water

Reproduction

• Production of new individuals more or less similar in form to the parent organisms.

Reproduction in Protozoa

• Sexual Reproduction

• Asexual Reproduction

Asexual Reproduction

• Binary fission

• Plasmotomy

• Budding

• Multiple fission

• Plasmogamy

Binary Fission

• One form of Mitosis

• The two daughter organismsproduced as a result of binaryfission carry all the cytoplasmicorganelles of the parent individual.

Plasmotomy

• Special type of binary fission.

• Protozoans (multinucleate) produce two ormore multinucleate daughter individuals.

Budding

• Modified fission

• Create small daughter individual in the form ofa bud

• When the bud breaks off ,It grows to full size.

Multiple Fission

• Sporulation

• The parent body simultaneously divides intoas many daughter individuals as there arenuclei.

Plasmogamy

• Rhizopoda

• Two or more individuals may fuse by theircytoplasm to form a plasmodium in which thenuclei remain distinct and they separate againunchanged afterwards.

Non sexual and not syngamy

Sexual Reproduction

• Syngamy or Fusion

– Hologamy

– Isogamy

– Anisogamy

– Autogamy

• Conjugation

Syngamy

• Compete fusion of two sex cells or gametes

• Form Zygote

– Hologamy

– Isogamy

– Anisogamy

– Autogamy

Hologamy

• Do not form gametes but themselves behaves as gametes

• Fuse together to form Zygote

Isogamy

• Two fusing gametes are similar in size and shape, differ in behaviour

• Produce gametes by multiple fission.

Anisogamy

• Two fusing gametes are different in size and shape as well as in behaviour

• Microgamete: male, large, motile

• Macrogamete: female , non motile

Autogamy

• Fusion of gametes derived from the same parent cell.

• Meiotic division.

Conjuagtion

– Random contact brings individuals of oppositemating types together (called conjugants)

–Meiosis results in four haploid pronuclei

– Three pronuclei and the macronucleusdegenerate. Mitosis and mutual exchange ofpronuclei is followed by fusion of the pronuclei.

– Conjugants separate. Nuclear divisions thatrestore nuclear characteristics of species follow.Cytoplasmic divisions may accompany theseevents

Parthenogenesis

• Gametes which fail at cross-fertilization,develop parthenogenetically.

Regeneration

• Process of regenerating animals’ lost parts.

• Nucleus plays an important role in this process.

Specific Representative

• Globigerina

• Lithocircus

• Ephelota

Globigerina

• Marine, found in the bottom of deep sea.

Found in creeping about on sea weeds

• Also found in brackish water.

Systematic Position

• Systematic position

Phylum: Protozoa

Sub phylum: Plasmodroma

Class: Rhizopoda

Order: Foraminiferida

Genus: Globigerina

Morphological Characters

• The body is enclosed in a perforatedcalcareous shell having few chambers.

• The chambers are compact and bulbous.

• Protoplasm is distinguishable into an externallayer and inner mass.

• The external layer of protoplasm or ectoplasmis full of foam and contains large vacuoles.

• Pseudopodia are numerous which protrudethrough pores of the shell.

Lithocircus

• Commonly Marine invertebrate.

• Found in deep sea.

• Exclusively exhibits Symbiosis

Systematic Position

• Systematic position

Phylum: Protozoa

Sub phylum: Plasmodroma

Class: Rhizopoda

Order: Radiolaria

Genus: Lithocircus


• Body is covered by a shell of siliceous skeleton.• The animalcule is provided with a central capsule

embedded in protoplasm.• The central capsules divides the protoplasm into

extra capsular and intra capsular protoplasm.• Extra capsuler protoplasm gives to radiating

thread like pseudopodia, while intra capsularprotoplasm caontains single nucleus.

• Contractile vacuole absent• Reproduction: asexual by binary fission

Ephelota

• Mainly Marine.

• Two types of tentacles such as

– long tentacles used for piercing

&

– short texta used for sucking.

Systematic Position

• Systematic position:

Phylum: Protozoa

Subphylum: Cillophora

Class:Suctoria

Genus: Ephelota


• Body is spherical and bearing stalk.

• There are two types of tentacles on the body.

• Protoplasm contains an oval nucleus and fewcontractile vacuole.

• Reproduction by budding.

• The distal half of the animal sprout a numberof small elevations or buds.

• In budding process the nuclei behave as in theordinary binary fission.

Importance of Protozoa

• Economically valuable in this Age of mammals.

Helpful Protozoa

Harmful Protozoa

Helpful in Sanitation

• Keep drinking water safe

• Holozoic protozoa feed on putrefying bacteria,thus helps to purify water.

Planktonic Protozoa as Food

• Food for man, fish and other organisms.

• Form a link in food chain in the oceanicenvironment.

Symbiotic Protozoa

• Symbiosis association

• Beneficial to both the partners forming adependency.

Harmful Protozoa

• Soil Protozoa

• Water Pollution

• Pathogenic Protozoa

– Pathogenic Sarcodines

– Pathogenic Flagellates

– Pathogenic Sporozoans

– Pathogenic Ciliates

Soil Protozoa

• Soil protozoans feed upon the NitrifyingBacteria

• Decreses the amount of nitrogen to soil.

Water Pollution

• Pollute water producing aromatic and oilysecretions with objectionable odours

• Some bioluminescent, living in sea , multiplyextensively and occurs the phenomenon calledbloom

• Destruction of fish , poisoning of ediblemolluscs.

Pathogenic Protozoa

• Cause disease to animals are termed as Pathogenic protozoa.

– Pathogenic sarcodines

– Pathogenic Flagellates

– Pathogenic Sporozoans

– Pathogenic Ciliates

• Entamoeba histolytica

• Leishmania donovani

• Plasmodium vivax

• Balantidium coli

Education

Clear Concept of Protozoa fish