Parasitic Modes of Life

Question 1

define Commensalism

Answer 1

relationship between two species which may benefit from but do not depend on one another

Question 2

define Phoresis

Answer 2

transport and shelter with no metabolic interactions

Question 3

define inquiline species

Answer 3

“house guest” - exploits the living space of another species

Question 4

define Mutualism

Answer 4

association where both species gain benefit but the association is not obligatory

Question 5

define symbiosis

Answer 5

relation between species - can be divided into intra- and interspecific forms

Question 6

define Parasitoid

Answer 6

intermediate stage between predation and true parasitism - attach themselves to a host, consuming and eventually killing it

Question 7

define Facultative parasitism

Answer 7

can survive as free-living forms but can also become fully functional parasites

Question 8

define Obligate parasite

Answer 8

parasite must find a receptive host in order to complete their life cycle

Question 9

define temporary/periodic parasite

Answer 9

parasite infect for short periods and verges on predation (inc. parasitoids)

Question 10

define permanent parasite

Answer 10

parasite remains with their host until they have completed the appropriate stage in their life cycle

Question 11

define Larval parasite

Answer 11

has a parasitic junenile stage

Question 12

define Hyperparasite

Answer 12

parasite of parasites

Question 13

define Microparasite

Answer 13

small parasite with short generation times, life spans shorter than host. Often provoke strong immune responses from vertebrate hosts

Question 14

define Macroparasite

Answer 14

generally do not multiply within or on their hosts and have relatively long generation times. Normally induce little to no host immune response, but cause weakening to produce morbidity (not mortality)

Question 15

define Mean Worm Burden (MWB)

Answer 15

Number/severity of macroparasites a host can tolerate without producing an immune response

Question 16

define Direct life cycles

Answer 16

those where there is a single host, e.g. with a parasitic adult form and free-living larval stage

Question 17

define Indirect life cycle

Answer 17

those with several hosts with particular roles throughout a parasitic life history

Question 18

define Accidental host

Answer 18

species not notmally part of the parasite life cycle but in permissive forms the parasite is able to complete its life cycle. In non-permissive forms the parasite fails to develop and dies within the host

Question 19

define Paratenic host

Answer 19

host that ingests larval stages and carries them in a form of arrested development, accumulating them until they have a chance of infecting a definitive host (also called transport hosts)

Question 20

define Definitive host

Answer 20

host in which sexual reproduction takes place

Question 21

define Intermediate host

Answer 21

asexual phase of the life cycle but often represent a multiplication stage

Question 22

define sacculinisation

Answer 22

evolving to lack sensory structures and motility because such functions are largely redundant - mostly seen in endoparasites