Parasitic castrationis the strategy, by aparasite,of blocking reproduction by its host, completely or in part, to its own benefit. This is one of six major strategies within parasitism.
Evolutionary strategy
editThe parasitic castration strategy, which results in the reproductive death of the host, can be compared with theparasitoidstrategy, which results in the host's death. Both parasitoids and parasitic castrators tend to be similar to their host in size, whereas most non-castrating parasites are orders of magnitude smaller than the host. In both strategies, an infected host is much less hospitable to new parasites than an uninfected one.[2]
Aparasitethat ends the reproductive life of its host theoretically liberates a significant fraction of the host's resources, which can now be used to benefit the parasite. The fraction of intact host energy spent on reproduction includes not justgonadsandgametesbut alsosecondary sexual characteristics,mate-seeking behavior, competition, and care for offspring. Infected hosts may have a different appearance, lacking said sex characteristics and sometimes even devoting more energy to growth, resulting ingigantism.[3]The evolutionary parasitologistRobert Poulinsuggests that parasitic castration may result in prolonged host life, benefiting the parasite.[4]
Parasitic castration may be direct, as inHemioniscus balani,a parasite ofhermaphroditicbarnacleswhich feeds on ovarian fluid, so that its host loses female reproductive ability but still can function as a male.[5]Parasitic castration may equally be indirect, as when a parasite diverts host energy from developing gonads or secretes castratinghormones.[4]
The parasitic castration strategy is used by some larvaltrematodeparasites ofsnailsand someisopodandbarnacleparasites ofcrustaceans.[3]For example, 18 species of trematodes parasitically castrate the California horn snail,Cerithidea californica.[6]
Certain other effects of a parasite on its host may appear similar to parasitic castration, such as the host'simmune systemdiverting energy from reproduction in response to numerous parasites that singly would have no impact onfecundityorfertility,orparasitoidsthat may consume reproductive organs first.[3]
Taxonomic range
edit| Parasite group | Parasite species | Host group | Host species | Remarks |
|---|---|---|---|---|
| ProtistaSporozoa | Mackinnonia tubificis | AnnelidaOligochaete | Tubifex tubifex | Destroys gonad[2] |
| ProtistaHaplosporidia | Urosporidium charletti | Cestoda | Catenotaenia dendritica | "Hypercastrator" (ahyperparasitethat castrates the parasite it parasitizes)[2] |
| PlatyhelminthesTrematoda | Bucephalus mytili | MolluscaBivalviaorGastropoda | various species | Destroys gonad, host grows larger[2] |
| PlatyhelminthesCestoda | various species | PiscesCyprinidae | various species | Destroys gonad, behavioral changes[2] |
| ArthropodaIsopoda | Hemioniscus balani | ArthropodaCirripedia | variousbarnacles | Drains ovarian fluid of hermaphrodite, but spares male function[5] |
| ArthropodaCirripedia | Sacculina | ArthropodaDecapoda | variouscrabs | Atrophies gonads, behavioral changes, partially feminizes males and stops regeneration of crab legs[2] |
| ArthropodaStrepsiptera | twisted-wing flies | ArthropodaHymenopteraorHemiptera | various species | Males feminized, females produce no eggs but instead disperse eggs of parasite[1] |
| PlatyhelminthesCestoda | Flamingolepis liguloides | Arthropoda | Artemiaspp. | Destroys gonads, behavioral changes[7] |
| ArthropodaHymenoptera | Crematogastersjostedti | Plant | Acacia drepanolobium | Antremoves axillary meristems, sterilizing trees.[8][9] |
References
edit- ^abZimmer, Carl (August 2000)."Do Parasites Rule the World?".Discover.Retrieved19 February2011.
- ^abcdefKuris, Armand M. (1974)."Trophic interactions: similarity of parasitic castrators to parasitoids"(PDF).Quarterly Review of Biology.49(2): 129–148.doi:10.1086/408018.
- ^abcLafferty, Kevin D.; Kuris, Armand M. (2009). "Parasitic castration: the evolution and ecology of body snatchers".Trends in Parasitology.25(12): 564–572.doi:10.1016/j.pt.2009.09.003.PMID19800291.
- ^abPoulin, Robert(2007).Evolutionary Ecology of Parasites(2nd ed.). Springer. pp.106, 111–114.ISBN978-0-691-12084-3.
- ^abBlower, S. M.; Roughgarden, J. (1988)."Parasitic castration: host species preferences, size-selectivity and spatial heterogeneity"(PDF).Oecologia.75(4): 512–515.doi:10.1007/BF00776413.Archived fromthe original(PDF)on 2016-03-04.Retrieved2011-02-11.
- ^Hechinger, R. F. (2010)."Mortality affects adaptive allocation to growth and reproduction: field evidence from a guild of body snatchers".BMC Evolutionary Biology.10:136.doi:10.1186/1471-2148-10-136.PMC2887408.PMID20459643.
- ^Yong, Ed (January 2013)."Parasites Make Their Hosts Sociable So They Get Eaten".National Geographic.Archived fromthe originalon January 31, 2013.Retrieved6 December2016.
- ^Stanton, M. L.; Palmer, T. M.; Young, T. P.; Evans, A.; Turner, M. L. (1999). "Sterilization and canopy modification of a swollen thorn acacia tree by a plant-ant".Nature.401(6753): 578–581.doi:10.1038/44119.
- ^Hall, S. R.; Becker, C.; Caceres, C. E. (2007-05-22)."Parasitic castration: a perspective from a model of dynamic energy budgets".Integrative and Comparative Biology.47(2). Oxford University Press: 295–309.doi:10.1093/icb/icm057.