What is Population interaction and 9 types of population interaction amongst Species including predation,protocooperation, mutualism, commensalism, ammensalism,parasitism,neutralism,and competition for resources.

1. POPULATION INTERACTION

2. What is population interaction ?
 Biological interactions are the effects thatthe organisms in
a community have on one another. In the natural world no
organism exists in absolute isolation,and thus every organism
must interact with the environment and other organisms.
 Population of two species may interact in ways that correspond
to combination of neutral, positive and negative
 Three of these combinations (+, +) (-,-) (+, -) are subdivided
resulting in NINE important interactions & relationships.

3. 9 Types of interactions
1) Neutralism
2) Direct Interference
3) Resource type competition
4) Amensalism
5) Commensalism
6) Parasitism
7) Predation
8) Protocooperation
9) Mutualism

4. CLASSIFICATION OF
INTERACTION
Negative interactions-
Neutralism
Directinterference
Competition for resource
Amensalism
Parasitism
Predation

5. Positive interaction-
Commensalism
Proto co-operation
Mutualism

6. NEUTRALISM
 Neutralism describes the relationship between two species that
interact but do not affect each other.
 Neither of the population is affected by interaction with each other
 Example : Rabbits, deer, frogs, live together in a grassland with no
interaction between them.

7. DIRECT INTERFERENCE
 Competition, direct interference type is the type of interaction whereboth
populations actively inhibit each other
 Occursdirectly between individuals via aggression etc.when the individuals
interfere with foraging, survival, reproduction of others.
 Example seen between the ant Novomessorcockerelliand red harvester ants,
where the formerinterferes with the ability of the latter to forage by plugging
the entrances to their colonies with small rocks.

8. RESOURCE TYPE
COMPETITION
 Competition is an interaction between organisms or speciesin which
both the species areharmed.
 Limited supply of at least one resource used by both can be a factor.
 Competition among members of the same species is known
asintraspecific competition
While
competition between individuals of different species is known
as interspecific competition.

9. AMENSALISM
 It is an antagonistic interspecific interaction in which onespecies is inhibited
while otherspecies is neither benefitted norharmed.
 It is also called antibiosis and the affected species is called amensal and the
affecting species is called inhibitor.
 Example:-Roots of certain plants produce allochemic substances which check
the growth ofother plants to conserve resources, such as, Convolvulus
arvensis, a weed inhibits the germination and growth of wheat.

10. COMMENSALISM
 Commensalism,isa classofrelationshipsbetweentwoorganismswhere
oneorganismbenefitsfromtheotherwithoutaffectingit.
 Thecommensal(thespeciesthatbenefitsfromtheassociation)may obtain
nutrients,shelter,support,or locomotionfromthehostspecies,whichis
substantiallyunaffected.
 Thecommensalrelationisoftenbetweena larger hostanda smaller
commensal;thehostorganismisunmodified,whereasthecommensal
speciesmay showgreat structuraladaptationconsonantwithitshabits,
as intheremorasthatrideattachedtosharksandotherfishes(example).

11. COMMENSALISM

12. PARASITISM
 Parasitism isa non-mutual symbiotic relationship
between species, where one species, the parasite, benefits at
the expense of the other, the host.
 Parasites canbe micro parasites, which are typically smaller,
such asprotozoa, viruses, and bacteria Examplesof parasites
include the plants mistletoe and cuscuta, and animalssuch
ashookworms.
 Parasites typically do not killtheir host, are generally much
smaller than their host, and will often live in or on their host for
an extended period.

14. PREDATION
 Itisa negative,directfoodrelatedinterspecificinteractionbetweentwo
speciesofanimalsinwhichlarger speciescalledpredatorattacks,kills
andfeedsonthesmallerspeciescalledprey.
 Predatorpopulationadverselyaffectthegrowthandsurvivalofsmaller
preypopulationandthereforepredationisconsideredan antagonistic
interaction.
 Example:-PlantlikeNepenthes(pitcherplant),Drosera(sundew),
Dionoeae(Venusflytrap)etc. feedoninsectstofulfiltheir nitrogen
requirement.
 Somepredators(suchas frog)actas preyforothers(snake)whichin
turnare preytoa highercarnivores(eagle).

15. Examples for predation

16. Significanceof predation
 a)Localspeciesdiversityisdirectlyrelatedtotheefficiencywith
whichthepredatorspreventthemonopolizationofan
environmentalarea byanyspecies.
 b)Predationkeepsthepreypopulationundercheck,soas to
maintainanecologicalbalance.Weak andlessefficientmembers in
thepreypopulationare removed.
 d)Mostimportantsignificanceisinthepracticalutilityofprey
predatorrelationshiponbiologicalcontrolofweedsandpests.Many
insectpestsare keptundercheckbyintroducingtheirpredatorinto
thearea. Fore.g.,Opuntiawhichbecomea seriousproblemin
Australiawas broughtundercontrolbyintroducingitsnatural
herbivoreCactoblastis(cochinealinsects).

17. PROTO COOPERATION
 It is a positive inter specificinteraction in which both the
partners are mutually benefitted and increase the chanceof
their survival.
 However, the interaction is not obligatory for their survivalas
both can live without this interaction.
 Example:- Crocodile bird (Pluvianus aegyptius) enters the
mouth of the crocodile and feed on parasiticleeches. By this the
bird gets food and the crocodile gets rid of blood sucking
parasites.

18. Positive interspecific relation between crocodile bird and
crocodile

19. MUTUALISM
 Itisa positiveinterspecificinteractioninwhichmembers oftwodifferent
speciesfavourthegrowthandsurvivaleachotherandtheirassociation
isobligatory.
 Boththepartnersare benefittedbythisinteraction.
 Mutualismisalsoreferredassymbiosisor symbioticinteractionandthe
partnersare referred as symbionts.
 Example:- Termites (white ants) are not capable of digesting wood,
which they ingest asfood. A multi flagellate protozoan
Trichonympha campanula, which lives in the intestine of white ant
secretes cellulaseenzyme to digest the cellulose of wood. In return,
the antprovides food and shelter to the protozoan.

20. Termites play important ecological role as decomposers by increasing the turno
And degradation

21. Thank you

22. REFERENCES
WEBSITES-
 www.tutorvista.com/content/biology
 www.wikipedia.org
 http://www.physicalgeography.net/fun
damentals
BOOKS-
Fundamentals of ecology Fifth Edition by
Eugene P. Odum & Gary W. Barrett