Lecture 34: Species Interaction - Parasitism and Mutualism

Solitary predators

animals that hunt alone, require death of host

micropredators

small animals that feed on other organisms, doesn’t kill host; only damages

microparasite

tiny organism that harms host & reproduces

examples of microparasites

COVID-19, cholera, trypanosoma, plasmodium

marcoparasites

visible to naked eye, complex lifestyles, multicellular parasite

examples of macroparasites

ticks, hookworms, pinworms, Ascaris

Filarial nematodes

transmitted by insects, complex lifestyles

hookwork is what type of parasite

nematode parasites

Parasitic castrators

reduce fecundity (birth rate) to zero but do not kill hosts

Parasitoids

Require exactly one host per generation

effects of parasitoids on hosts

lay eggs on or in host. offspring eat and kill host

examples of parasitoids

wasps, gordian worms (nematomorpha), flies, Romanomermis nematodes

Trophically transmitted parasite

a parasite that requires eating one host in order to transmit to the next

Symbiosis

Two or more species live together in permanent close interaction, type of mutualism

commensalism

one species benefits, other is not effected

Mutualism-parasitism continuum

describes how symbiotic relationships can shift from mutualism to parasitism

mutualism: pollination

Pollinators transport plant’s pollen; plant gives pollinators sugars (nectar)

Co-evolutionary arms race

two species evolve in response to each other

examples of co-evolutionary arms race

predator-prey or host-parasite relationships