Type of parasite & host

Animal Association, Parasite, Host and its Type

Balwant SinghBabasaheb Bhimrao Ambedkar University Lucknow

Animal AssociationsThe relationship between two or more

organisms are termed as animal association.

Type’s of Animal

Association 1) Phoresis

2) Matualism

3) Commensalism

4) Parasitism

PHORESISIn this type of relationship, the phoresis

has been regarded as a type of symbiotic relationship in which one organism (smaller called phorant) is mechanically carried on or in another species (larger called host).

In phoresis, there is no physiologicaly or biochemicaly dependence on the part of the host or symbiont.

MUTUALISMA close association between two

different organism, in which one derives benefit from the other is known as mutualism.

The mutuals are metabolically dependent on one another; one cannot survive in the absence of the other.

COMMENSALISMThe association between two different

species of organisms where one is benefited and another one neither benefited nor harmed is commensalism.

The organism which give shelter in commensalism is known as the host and that receive shelter is known as commensal.

Escherichia coli (bacteria) lives as endocommensal in the intestine of Man. It receives nourishment and completes its life cycle without doing harm to Man.

PARASITISMAn organism which depends on other

organism for food, shelter and protection is called a parasite.

The organism on which a parasite lives is known as the host. The association between a host and parasite is called parasitism.

Definition of parasitism have traditionally focused upon some ecological aspect of the parasite-host intraction.

Parasitism - a way of life

Parasite and Parasitism are terms that define a way of life rather than a evolutionary related group of organisms

Parasitology historically covers a diverse collection of metazoan and protozoan organisms

What is a Parasite?An organism that lives in a symbiotic

relationship with a phylogenetically unrelated organism over a prolonged period of time.

An organism which depends on other organism for its food, shelter and protection is called a parasite.

A Parasite lives in or on its host.

Relationship lasts the lifetime of the host.

Type of ParasitesThe parasite are categorized on the following

basis-

1) On the basis of Generation

2) On the basis of Pthogencity

3) On the basis of Localization

4) On the basis of Dependency

On the basis of Generation1) Monogenetic Parasite- These require hosts

of only one species to complete their life spon.

e.g.-Ancylostoma duodenale, Diplozoon paradoxum

2) Digenetic Parasite- These require hosts of two different speciese to complete their life spon.

e.g.-Leishmania donovani Fasciola hepatica

On the basis of Pathogencity1) Pathogenic Parasite- Those parasite which are

caused disease and act as a pathogen called pathogenic parasite.

e.g.-Taenia solium (caused taeniasis in Man)

2) Nonpathogenic Parasite- They are not cause any disease in the host.

e.g.-Taenia hominis (habiting in the intestine of Man without causing harm or disease)

3) Intermittent Parasite- They are not constently associated with the host. They obtain nurishment from host at time to time.

e.g.-Bed bugs (Suck the blood meal from Man)

On the basis of Localization1) Ecto Parasite- Those parasite which are live on the

host or Out side of the host are called ectoparasite. e.g.- Bed bugs, Mites, Teaks etc. (Mostaly Arthropods Parasites)

2) Endo Parasite- Those parasite which are live in the host or Inside of the host are called endoparasite.

e.g.- Plasmodium vivex, Wuchereria bancrofti etc.

(Generally Protozoans, Helminthis & Neamtods Parasites)

On the basis of Dependency1) Facultative Parasite- These parasite which can

live in hosts if it is available, but capable of living independently if its host is not available, are known as facultative parasite.

e.g.- Mycobacterium tuberculosis (cause tuberculosis in man is a facultative parasite)

2) Obligate Parasite- Those parasite which depend upon the specific host throughout life are called obligate parasite.

e.g.- Taenia solium, Ancylostoma duodenale

WANDERING PARASITE

Also known as Aberrant parasite.

Sometime the parasite happen to reach

a place which is not its usual site of

localization. Such parasite which fails

to reach its normal destination is

termed as aberrant or wandering

parasite.

What is the host ?The organism on or in which a parasite

lives are known as host.

An organism which harbouring a parasite is called host.

Host usually larger than their parasite.

Type of host

1) Definitive host

2) Intermediate host

3) Paratenic host

4) Reservoir host

5) Vector host

Definitive hostThe definitive host is the one in which a

parasite reaches sexual maturity and under goes sexual reproduction.

It is mostly vertebrates.E.g.-1) For Plasmodium vivax definitive

host is female Anopheles mosquito. 2) For Taenia solium definitive host is

man. 3) For Wuchereria bancrofti definitive

host is man.

Intermediate hostThe host in which asexual development of the

parasite occurs is referred as intermediate host.It is usually invertebrate.In some cases two or more IH are involved. And

also two type-1) Passive IH (molluscs in the case of

Schistosoma)2) Active IH ( tsetse fly in the case of

Trypanosoma) E.g.-1) For Plasmodium vivax IH is man. 2) For Taenia solium IH is pig. 3) For Wuchereria bancrofti IH is female

Culex mosquito.

Paratenic host Also known as Transport host or Carrier host

or Transfer host.

Sometime the parasite enters a host in which it does not undergo any development but remains alive till it gains entry in the Definitive or Intermediate host. Such a host termed as paratenic host.

They are believed to bridge the ecological gap between the Definitive and Intermediate host.

E.g.-Housefly (contamination agent and disease causing pathogens)

Resorvoir hostAlso known as Temporary host.

In the absence of regular hosts, some

parasites survive in the reservoir hosts.

Reservoir host become the source of

infection to regular hosts.

Reservoir hosts are not essential for the

parasite to complete its life cycle.

E.g.- Monkey is reservoir host for Plasmodium.

Vector hostIt is the host in which a part of life cycle

of a parasite takes place and is also instrumental in the transmission of the parasite from main host to other.

Mostly typical Arthropods are the refers to vector hosts. Also two types-

1) Biological Vectore.g.-Haematophagous arthropodes such as

mosqutoes.2) Mechanical Vectore.g.-Flies for transport of Amoebal cysts.

HYPERPARASITISMWhen an organism which

parasitizes another parasite are

known Hyperparasite and this

phenomenon are termed

Hyperparasitism.