Sargent Lab - Research

Courtship and Mate Choice in Fishes:
Integrating Behavioral and Visual Ecology

This project focuses on the interaction between male breeding coloration as honest signals and female choice, within the constraints of the visual ecology of the species in question. Current projects focus on two species of poeciliid fishes, Perugia's Limia (Limia perugiae) and the guppy (Poecilia reticulata). 

Representative Publications:

Rush, VN, McKinnon, JS, Abney, MA & Sargent, RC, 2003. Reflectance spectra from free-swimming sticklebacks (Gasterosteus): Social context and eye-jaw contrast. Behaviour, 140:1003-1019. (pdf) 

Sargent, RC, Rush, VN, Wisenden, BD & Yan, HY, 1998. Courtship and mate choice in fishes: integrating behavioral and sensory ecology. American Zoologist, 38:82-96. (pdf)

Condition Indicators in the Limiting Sex

A female convict cichlid, Archocentrus nigrofasciatum. The orange coloration generally is not expressed in males.

This project focuses on the functional significance of female breeding coloration in the convict cichlid, Archocentrus nigrofasciatum. Preliminary data suggest that this coloration may correlate with female fecundity, and possibly energy reserves. Current experiments are examining how male and female convict cichlids respond to female breeding coloration. Future projects will examine female signaling in poeciliid fishes. This project began as Kasi Jackson's doctoral dissertation.

Representative Publications:

Jackson, JK, Brown, AL, Lloyd, TK, Orsborne, T, & Sargent, RC, In preparation. Effects of diet on female breeding coloration in the convict cichlid, Archocentrus nigrofasciatum. 

This project focuses on the interaction between male sexual harassment of females, and female dominance hierarchies in the mosquitofish, Gambusia affinis. Previous work found that female density dependence can swamp the negative effects of male harassment, such that females have higher fecundity and growth at high male and low female density, despite experiencing higher rates of male harassment under these conditions (Smith & Sargent 2006). Preliminary data suggest that females have size dependent dominance hierarchies, that males preferentially harass larger females, and that male harassment can reverse the size dependent effects of female dominance on growth in subordinate females. This project began as Chad Smith's masters thesis. Current experiments include using microsatellite DNA markers to test hypotheses on potential genetic benefits of multiple mating.

Representative Publications:

Smith, CC & Sargent, RC, 2006. Female fitness declines with increasing female density but not male harassment in the western mosquitofish, Gambusia affinis. Animal Behaviour 71:401-407. (pdf)

Smith, CC, 2007. Independent effects of male and female density on sexual harassment, female fitness, and male competition for mates in the western mosquitofish. Behavioral Ecology and Sociobiology 61:1349-1358.(pdf)