| The condition dependent model of female choice contends that ornaments and elaborate displays are costly to produce and maintain. Since salinity imposes a physiological cost, fish raised at higher salinities should have fewer resources to invest in growth and reproduction. As salinity increases, fish should be smaller, have more poorly developed ornamentation, and have lower display rates. Males should adopt the alternative mating strategy of attempted copulations because of the lower amount of energy required. The objective of this experiment was to determine if metabolic costs induced by salinity would affect the reproductive biology and life history of the guppy. Results suggest there is a significant size and condition difference between males raised in the control environment and those raised in the three salinity treatments. Males raised in the control environment also displayed significantly more often and elicited more female responses than those from the three salinity treatments. Fish raised in salinity tended to adopt alternative mating tactics. This suggests that male display is an honest signal of male condition, and the cost induced by salinity directly affects condition, which affects display rate, which affects female preference. |
