Male and female cooperatively breeding fish provide support for the "Challenge Hypothesis"

Julie K. Desjardins, Mark R. Hazelden, Glen J. Van der Kraak and Sigal Balshine

Behavioral Ecology, 2006, vol. 17, issue 2, 149-154

Abstract: The idea that territorial aggression is regulated by androgens and that aggression itself can modulate androgen levels is well established in males. In many species, females also display aggressive behavior, yet little work has been conducted on the effects of female aggression on hormone levels. In this study, we compared the effects of a simulated territory intrusion (a method for testing the Challenge Hypothesis) on males and females of the fish, Neolamprologus pulcher. This cichlid fish from Lake Tanganyika is a particularly useful species to examine sex differences in the behavioral mediation of hormones as breeding pairs remain in a territory year round and both sexes defend this territory against conspecific and heterospecific intruders. In our study, both sexes indeed aggressively defended their territory against a simulated territory intruder. In response to intruders, both males and females displayed elevated levels of circulating 11-ketotestosterone, but only females exhibited increases in testosterone. Neither aggressing male nor female fish showed changes in estradiol levels compared to control (nonaggressing) fish. Residents were more aggressive than the intruders and won most of the interactions. However, residents (or winners) did not show higher hormone levels than intruders (or losers). We suggest that aggression commonly modulates androgen levels in both male and female teleost fish. Copyright 2006.

Keywords: Cichlidae; estradiol; 11-ketotestosterone; Lake Tanganyika; Neolamprologus pulcher; sexual differences; territorial aggression; testosterone (search for similar items in EconPapers)
Date: 2006
References: Add references at CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
http://hdl.handle.net/10.1093/beheco/arj018 (application/pdf)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:oup:beheco:v:17:y:2006:i:2:p:149-154

Ordering information: This journal article can be ordered from
https://academic.oup.com/journals

Access Statistics for this article

Behavioral Ecology is currently edited by Louise Barrett

More articles in Behavioral Ecology from International Society for Behavioral Ecology Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK.
Bibliographic data for series maintained by Oxford University Press ().