Sexually selected signals can be viewed as life history traits. In the guppy (Poecilia reticulata) and the sex role reversed pipefishe (Syngnathus typhle) sexual signals are well understood, but their relation to life history decisions remain unexplored.T he proposed project will test how life history traits, resource budgets and predation risks affect female ornament display and female-female competition in these two species. How are these trade-offs affected by a female's resource budget? Does predationr isk affect trade-offs? Under environmental, will allocation to body size, to ornament display, to competition or to eggs suffer first? Furthermore, do the two characters primarily used to attract males, body size and ornamentation, differ in costs to the females. Do females with different resource budgets differ in their allocation to growth and ornamentation? Mutual mate choice and mati ng competition is another poorly investigated area. Does the most choosy sex compete over the best partner, and are th e best competitive individuals choosy? Can poor individuals of the choosy sex afford to be choosy, or do they need to court? How mutual m ate choice and mating competition interact with life history is a fascinating but so far poorly understood field of r esearch.