1060 SCE

11

Organism interactions

-          physical and chemical environment, and other organisms (abiotic and biotic factors)

Intraspecific interactions

between individuals or the same species for limited resources (maternal care, community interactions)

Interspecific interactions

between species

Symbiosis

living together (in/on or in close proximity)

Mutualism

both benefit. Clownfish and anemone

Commensalism

benefits one, indifferent. Adult stomach flukes in cattle

Parasitism

– benefits at expense of host. May cause disease or death

Parasites that live within host

endoparasite

Parasites that live outside host

ectoparasite

Human parasite eg

Malaria

Animal parasite eg

Coccidiosis

Animal and human parasite

African trypanosomiasis

Malaria

o   Apicomplexan

o   Invades red blood cells, causing them to become sticky

-          Haemolysis (malaria)

– destruction of red blood cells and release of toxins

Coccidiosis

o   Apicomplexan

o   Common in intensive livestock production

o   Kangaroos sensitive

o   Associated with stress and overcrowding

Cerebral malaria

causes comatose condition (brain becomes inoxic)

-          African trypanosomiasis

• caused by flagellate

• o   One health problem

  o   Humans – sleeping sickness

  o   Animals – nagana

  o   Transmitted by Tsetse fly

-          Why is African trypanosomiasis a one health problem?

o   Affects human health through infection and human livelihood by causing disease in their animals

Nagana in cattle

o   Milk and meat shortages

o   Kills 3 million cows a year

-          Sleeping sickness in humans

o   Parasite lives in blood

o   Invades CNS (fatal)

o   Comatose