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Social situation, sperm competition, and sex allocation in a simultaneous hermaphrodite parasite, the cestode Schistocephalus solidus

Schärer, Lukas and Wedekind, Claus. (2001) Social situation, sperm competition, and sex allocation in a simultaneous hermaphrodite parasite, the cestode Schistocephalus solidus. Journal of Evolutionary Biology, 14 (6). pp. 942-953.

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Official URL: http://edoc.unibas.ch/dok/A5250531

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Abstract

Evolutionary theory predicts an influence of mating group size on sex allocation in simultaneous hermaphrodites. We experimentally manipulated the social situation during reproduction in a simultaneous hermaphrodite parasite, the tapeworm Schistocephalus solidus, by placing worms as singles, pairs or triplets into an in vitro system that replaces the final host. We then determined the reproductive allocation patterns after 24 h (i.e. before the start of egg release) and after 72 h (i.e. around the peak of egg release rate) using stereology. After 24 h, sex allocation strongly depended on worm volume (which is determined in the second intermediate host), but was not significantly affected by the social situation experienced during reproduction. After 72 h, worms in groups had less vesicular sperm (i.e. sperm to be used in future inseminations) than singles. They also stored significantly more received sperm in their seminal receptacles than singles, suggesting that more sperm had been transferred in groups. Moreover, worms in triplets stored significantly more received sperm than worms in pairs, suggesting that they either mated more often and/or transferred more sperm per mating. This suggests a behavioural response to the increased risk of sperm competition in triplets. We further discuss the relative importance of sex allocation decisions at different life-history stages.
Faculties and Departments:05 Faculty of Science > Departement Umweltwissenschaften > Zoologie > Evolutionary Biology (Schärer)
UniBasel Contributors:Schärer, Lukas
Item Type:Article, refereed
Article Subtype:Research Article
Bibsysno:Link to catalogue
Publisher:Blackwell
ISSN:1010-061X
e-ISSN:1420-9101
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:05 Oct 2017 05:49
Deposited On:22 Mar 2012 14:04

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