Data from: Anatomy of a cline: dissecting anti-predatory adaptations in a marine gastropod along the U.S. Atlantic coast
Kosloski, Mary E.; Dietl, Gregory P.; Handley, John C. (2016), Data from: Anatomy of a cline: dissecting anti-predatory adaptations in a marine gastropod along the U.S. Atlantic coast, Dryad, Dataset, https://doi.org/10.5061/dryad.fc208
The scope of anti-predatory adaptation is expected to be greater in warm than in cold environments. High temperatures lower the costs associated with the production and maintenance of energetically expensive traits and enable ecological interactions to intensify. We tested this hypothesis by characterizing the expression of anti-predatory morphology within a marine gastropod species (the knobbed whelk, Busycon carica) over a large (>1,400 km) geographic area that spans more than 10°C annual temperature variation. We also conducted experimental predation studies with a powerful durophagous predator, the stone crab (Menippe), to verify the anti-predatory advantages of a heavily ornamented shell morphology (e.g., increased thickness, pronounced spines), and we used repair scar data to assess clinal variation in selective pressure from predators. We predicted that repair scar rates would be greatest in warm southernmost latitudes, and that expression of energetically costly anti-predatory morphology would peak in concert with elevated predation pressures. Experiments confirmed that whelks with energetically costly, heavily ornamented shells had higher survivorship rates than those with weakly ornamented shells. As predicted, we also found that the expression of anti-predatory traits was greatest in the southern part of B. carica’s range. After standardizing shells for size, shape, and exposure time to enemies, repair scar rates also peaked to the south. Taken together, these results suggest that the expression of anti-predatory traits along the geographic cline is governed by the interaction of two selective factors: temperature and predation, with the former acting as the ultimate control on the scope of adaptation both by escalating predation pressure in the southern part of B. carica’s range and by physically limiting (to the north) and facilitating (to the south) the production of anti-predatory traits. Feedbacks between temperature and predation thus causally interact to enable and drive, respectively, the observed geographic cline in energy-intensive anti-predatory shell traits.
East Coast United States