Parasitic Modes of Life Flashcards
(43 cards)
Define commensalism.
Literally ‘eating at the same table’ but NO metabolic dependence - purely ecological relationship. Both able to olive full lives without other member of relationship.
Define phoresis.
Transport and shelter with no metabolic interactions.
What is an example of a commensal relationship?
Clownfish and sea anemones.
What is an example of a phoresic relationship?
The defenceless pearl fish Fieraster that is an inquiline species living in the respiratory trees of holothurians.
Define inquiline.
House guest.
Define mutualism.
Associations where both species gain benefits but the association is not obligatory, e.g. cleaner fish and shrimps.
What can symbiotic relationships be divided into?
Intra- and inter-specific forms.
What is the difference between facultative and obligate symbiotic relationships?
Obligate: both parties depend on each other to survive.
Facultative: they do not require each other to live.
What are examples of symbiosis?
Anglerfish - dwarf males.
Echiurans - same.
Vent worms - riftia - chemoautotrophic bacteria.
Algae and fungi form lichens.
What is the difference between predation and parasitism.
Predators kill and eat prey species on their first encounter, whereas parasites feed on their hosts, reducing the life span but not as an immediate consequence of the encounter.
What is a parasitoid?
An intermediate stage between predation and true parasitism. They attack themselves or lodge within a host, consuming it and eventually killing it.
What is an example of a parasitoid?
The Phronima arthropod eating salps, and fish leeches. Mostly insects tho.
What is an ecto-parasite and what is an endo-parasite?
Ecto lives outside and endo lives inside.
Define facultative.
Can survive as free-living but can also become fully functional parasite, e.g. some ciliates.
Define obligate.
Must find a receptive host in order to complete their life cycle.
What is a temporary parasite?
They infect for short periods, e.g. leeches, & verge on predation. When they revisit a host they may be PERIODIC.
What is a permanent parasite?
They remain with their host until they have completed the appropriate stage in their life cycle, and may be harboured by the host for long periods, sometimes decades in the case of gut helminths in long-lived vertebrates.
What are larval parasites?
Those with parasitic juvenile stages.
What is an example of a parasitic larvae?
The ‘praniza’ larvae of some isopods. They have huge jaws to attack to fish skin, where it feeds on blood & mucus & can cause serious mortalities in juvenile fish. Eventually drop off and metamorphose on bottom. Adults free-living and inhabit burrows in sand/algal mats w/ harem of females.
What are hyperparasites?
Parasites of parasites.
What is an example of a hyperparasite?
Monogenean Udonella, that parasitises an ectoparasitic copepod Caligus rogercresseyi found on the Chilean rock cod.
What are microparasites?
Very small compared to hosts & have short generation times, often w/ life spans shorter than hosts. Often provoke strong immune responses from vertebrate hosts.
What is an example of a microparasite?
Protists and small helminths. Giardia causes severe gastrointestinal effects which may help to increase its dispersal and infection of new hosts.
What are macroparasites?
They generally do not multiply with on on their hosts and have relatively long generation times. They induce little or no host immune response, depending on the severity of the infection. They do cause weakening of the host and produce morbidity rather than mortality.
