Skip Navigation



Behavioral Ecology Advance Access published online on June 12, 2007
Behavioral Ecology, doi:10.1093/beheco/arm044
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Lay Summary
Right arrow All Versions of this Article:
18/4/776    most recent
arm044v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Aspbury, A. S.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Aspbury, A. S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2007. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org

Sperm competition effects on sperm production and expenditure in sailfin mollies, Poecilia latipinna

Andrea S. Aspbury

Department of Biology, Texas State University-San Marcos, San Marcos, TX 78666, USA

Address correspondence to A.S. Aspbury. E-mail: aspbury{at}txstate.edu.


  Abstract

Sperm competition risk (SCR) models predict that if there is a low probability a male's ejaculate will compete with another male, individuals should invest less sperm in a mating, whereas if the probability of competition is high, males should invest more sperm. Alternatively, models of sperm competition intensity (SCI) predict that increased intensity of sperm competition leads to maximal sperm investment when a male faces a single competitor. Few studies have examined predictions of these models for males of varying size, and none have examined effects of sperm competition on both sperm production and expenditure. To examine effects of sperm competition on these variables, male sailfin mollies (Poecilia latipinna) from 3 size classes were randomly assigned to one of 3 treatments that manipulated SCR and SCI: 1) no risk, low intensity; 2) risk present, medium intensity; and 3) risk present, high intensity. Male sailfin mollies produced more sperm in the high-intensity treatment than in the low-intensity treatment. Sailfin mollies in the risk present treatments expended more sperm than those males in the risk absent treatment. There was no significant difference in sperm expenditure between the medium intensity and the high-intensity treatment, indicating that maximal sperm investment does not occur when the number of competing males is one. Furthermore, small males expended more sperm than medium and large males. These results suggest that male sailfin mollies respond as predicted to SCR, but not to SCI. I suggest that male size effects and sperm production should be considered in theoretical treatments of optimal male sperm investment strategies.

Key words: cryptic male choice, livebearing fish, operational sex ratio, strategic allocation.

Received 15 December 2006; revised 20 March 2007; accepted 9 April 2007.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Behav EcolHome page
B. B. M. Wong and M. McCarthy
Prudent male mate choice under perceived sperm competition risk in the eastern mosquito fish
Behav. Ecol., March 1, 2009; 20(2): 278 - 282.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.