Meeting Abstract
The adaptive value of phenotypic plasticity can be limited by several factors, such as the epi-phenotype limit, which is when a newly induced phenotype is not fully integrated with the previous phenotype. Additionally, some inducible morphologies are irreversible, which can result in phenotype-environment mismatch when environmental conditions change. Many marine gastropods thicken their shell in response to shell-crushing predators, an inducible defense, and some are capable of remodeling shell that has already been deposited. However, previous studies of inducible defenses tend to examine only recent shell growth, and not secondary modifications to older parts of the shell (i.e., remodeling). Shell remodeling could allow for reversibility in inducible shell thickening and mitigate epi-phenotype limits. Therefore, we examined plasticity in shell construction and remodeling in Nucella lamellosa, which displays a strong inducible shell thickening response to the predatory crab, Cancer productus. In response to this predator N. lamellosa constructed a thicker shell at the aperture and body whorl, with an increase in both shell microstructural layers at the aperture, but only in one layer in the body whorl. Snails also exhibited shell remodeling in response to C. productus; producing an overall thicker shell in older apical whorls. Thus, snails produced the thick or thin shell phenotype throughout all parts of the shell depending on treatment, circumventing the epi-phenotype limit, and suggesting reversible phenotypic plasticity in shell thickness in N. lamellosa.
