ST MARY, CM*; LINDSTR�M, K; University of Florida; University of Helsinki: Stabilizing and directional selection acting on male parental care

Life-history theory argues that there exists a trade-off between investment in parental care and mate attraction when males provide parental care. However, when females use care in mate choice, parental care also functions in mate attraction (i.e., there is sexual selection for care). This raises the question of whether there exists a trade-off between these components of fitness in such systems. We show that sexual selection for care is acting on parental care in the sand goby, Pomatoschistus minutus. Furthermore, we demonstrate that males are plastic in their response to increased mating opportunities; showing increased care as mating opportunities increase. Finally, we characterize the pattern of selection acting on a key component of care, fanning, in the presence and absence of mating competition and find that selection on care occurs only in a competitive environment. We conclude that care must be considered as both a display and a life-history trait and thus our current theoretical understanding of its evolution may be incomplete.