Meeting Abstract

4.2  Thursday, Jan. 3  Finding the Lady in Red: The effects of turbidity on sexual signaling in the blue crab Callinectes sapidus BALDWIN, J. L. *; JOHNSEN, S.; Duke University; Duke University jamie.baldwin@duke.edu

Research has suggested that male blue crabs (Callinectes sapidus) select females based on the redness of their claws. Many estuaries in which C. sapidus mate experience eutrophication and resulting turbidity due to land-derived nutrients accumulated in freshwater runoff. Because it reduces chromatic and achromatic contrasts, higher turbidity may interfere with sexual signaling in these crabs. We examined this possibility by first modeling the light fields in clear and turbid coastal waters using measured inherent optical properties and radiative transfer software. Next, the modeled light fields were compared to the spectral sensitivity and spatial resolution of the C. sapidus eye, allowing us to estimate the chromatic and achromatic contrast of the females� red claws against the carapace and background in clear and turbid waters. The results are discussed in relation to blue crab sexual signaling and reproduction and the effects that environmental disturbances may have on the abundance of this ecologically and economically important species.