Background color convergence of prey can reduce predation rates by visual predators, occurring through local adaptation or phenotypically plastic responses. We assessed the capacity for substrate color-induced melanization in eight turtle species within the groups: Chelydridae, Emydidae, Kinosternidae, and Trionychidae by rearing individuals on black or white substrates for 160 days. In all aquatic turtle species, integuments of the head and carapace in the individuals that were reared on a black substrate were darker than on those reared on a white substrate. In the terrestrial Terrapene carolina carolina, however, no significant differences in dorsal head skin or carapace color were observed between treatments. Histological examination of tail tips in three aquatic species (Chelydra serpentina serpentina, Graptemys geographica, and Trachemys scripta) indicated that substrate color-induced melanization is morphological involving the transfer of melanosomes from basal epidermal melanocytes to adjacent keratinocytes. Interestingly, substrate color-induced melanization in a Pleurodiric species apparently involves physiological color change suggesting possible differences between Cryptodiric and Pleurodiric lineages. However, we could not rule out physiological color change in the turtles of our study.
|Original language||English (US)|
|Title of host publication||2014 Joint Meeting of Ichthyologists and Herpetologists, 31 July - 3 August 2014 Chattanooga, Tennessee|
|State||Published - 2014|
Rowe, J., Miller, B., Stuart, M., Snyder, C., Tucker, J., Clark, D., Wittle, L., & Lamer, J. T. (2014). Substrate Color-induced Melanization in Eight Turtle Species from Four Chelonian Groups. In 2014 Joint Meeting of Ichthyologists and Herpetologists, 31 July - 3 August 2014 Chattanooga, Tennessee (pp. 428)