Classification Parasitism

1 classification

1.1 ectoparasites
1.2 endoparasites
1.3 mesoparasites
1.4 parasitoids
1.5 hyperparasites
1.6 social parasites
1.7 adelpho-parasites
1.8 sexual parasites

classification

human head lice (pediculus humanus capitis) obligate ectoparasites.



ectoparasites

parasites live on outside of host, either on skin or outgrowths of skin, called ectoparasites. directly transmitted between hosts. examples include lice, fleas, , mites.

endoparasites

schistosoma mansoni obligate endoparasite of human blood vessels, causing schistosomiasis (bilharzia).

those live inside host, including parasitic worms (helminths), called endoparasites. endoparasites can exist in 1 of 2 forms: intercellular parasites (inhabiting spaces in host s body) or intracellular parasites (inhabiting cells in host s body). coinfection multiple parasites common.

intracellular parasites, such pathogenic (disease-causing) protozoa, bacteria or viruses, tend rely on third organism, carrier or vector, transmit them host.

autoinfection infection of primary host parasite, particularly helminth, in such way complete life cycle of parasite happens in single organism, without involvement of host. can occur intestinal parasite strongyloides stercoralis. strongyloidiasis involves premature transformation of noninfective larvae infective larvae, can penetrate intestinal mucosa (internal autoinfection) or skin of perineal area (external autoinfection).

mesoparasites

those parasites living in intermediate position, being half-ectoparasites , half-endoparasites, called mesoparasites. example, cod worm lernaeocera branchialis invades gill tissue of host fish, grows tubelike structure cuts through body tissues until reaches fish s heart, through robs host of blood. rear end of parasite remains outside, can scatter eggs water.

a parasitoidal wasp ovipositing body of spotted alfalfa aphid


parasitoids

a parasitoid sooner or later kills prey, form of parasitism close predation. idiobiont parasitoid wasps sting prey on capture, either killing them outright or paralyzing them immediately. prey carried nest, egg laid on or in it, , parasitoid develops rapidly. koinobiont parasitoid wasps lay eggs in young hosts, larvae, allowed go on growing, host , parasitoid develop extended period. koinobionts regulate host s development hormonally, example preventing pupating or making moult whenever parasitoid ready moult.

hyperparasites

a hyperparasitoid chalcid wasp (pteromalidae) on cocoons of host, braconid wasp (microgastrinae), koinobiont parasitoid of lepidoptera

a hyperparasite or epiparasite feeds on parasite, exemplified protozoan living in helminth parasite. term used more loosely refer parasitoids hosts either parasites or parasitoids. hyperparasitoids may facultative or obligate, , young may develop inside or outside host s body, larva.

social parasites

the large blue butterfly mimic , social parasite of ants.

social parasites take advantage of interactions between members of social organisms such ants, termites, , bumblebees. examples include large blue butterfly, phengaris arion. larvae employ mimicry parasitize species of ants, bombus bohemicus, bumblebee invades hives of other species of bee , takes on reproduction, young raised host workers, , melipona scutellaris, eusocial bee virgin queens escape killer workers , invade colony without queen. extreme example of social parasitism ant species tetramorium inquilinum of alps, lives exclusively on backs of other species of tetramorium host ants. tiny , weakened bodies, have evolved single task: holding on host, since if fall off, die.

in kleptoparasitism (from greek κλέπτης (kleptes), thief), parasites appropriate food gathered host. example brood parasitism practiced cowbirds, whydahs, cuckoos, , black-headed ducks not build nests of own , leave eggs in nests of other species. host behaves babysitter raise young own. if host removes cuckoo s eggs, cuckoos return , attack nest compel host birds remain subject parasitism.

intraspecific social parasitism may occur, in parasitic nursing, individual young take milk unrelated females. in wedge-capped capuchins, higher ranking females take milk low ranking females without reciprocation. high ranking females benefit @ expense of low ranking females.

parasitism can take form of isolated cheating or exploitation among more generalized mutualistic interactions. example, broad classes of plants , fungi exchange carbon , nutrients in common mutualistic mycorrhizal relationships; however, plant species known myco-heterotrophs cheat taking carbon fungus rather donating it.

adelpho-parasites

the male anglerfish ceratias holboelli lives tiny sexual parasite permanently attached below female s body.

an adelpho-parasite (from greek αδελφός (adelphos), brother) parasite in host species closely related parasite, being member of same family or genus. example of citrus blackfly parasitoid, encarsia perplexa, unmated females of may lay haploid eggs in developed larvae of own species. these result in production of male offspring. marine worm bonellia viridis has similar reproductive strategy, although larvae planktonic.

sexual parasites


cuscuta (a dodder), stem holoparasite, on acacia tree

in many animals, males smaller females. in species of anglerfish, such ceratias holboelli, males small have become sexual parasites, wholly dependent on females of own species survival, , unable fend themselves. female nourishes male , protects him predators, while male gives nothing except sperm female needs produce next generation.