Predation by shell-breaking crabs on a marine gastropod along a latitudinal gradient in the SW Atlantic: Influence of extrinsic and intrinsic factors

Biotic interactions—and predation in particular—are thought to follow a latitudinal gradient, increasing towards the tropics; yet empirical evidence remains contradictory and largely based on studies from the Northern Hemisphere. Moreover, the role of environmental variables shaping latitudinal gradients of predation intensity has seldom been tested. Here, we quantify predation by shell-breaking crabs on modern shells of the marine gastropod Trophon geversianus along a latitudinal gradient (40°–54°S) on the SW Atlantic coast. We further evaluate how intrinsic factors (four shell morphometric traits) and extrinsic factors (seven environmental variables and the biogeographic region) jointly influence predation patterns. Fragmentation from crushing predation affected 37% of the shells (544 out of 1,480), with the most frequent damage types being major body whorl damage (28%), deep aperture chips (11%), and extensive aperture chips (6%). When analysed by biogeographic province, fragmentatio..., , # Predation by shell-breaking crabs on a marine gastropod along a latitudinal gradient in the SW Atlantic: Influence of extrinsic and intrinsic factors

Dataset DOI: 10.5061/dryad.vx0k6dk4s

### Description of the data and file structure

Summary

This dataset supports a study investigating how oceanographic variables influence the frequency of shell-breaking crab traces on the marine gastropod Trophon geversianus across 34 sites in the Southwestern Atlantic. The dataset integrates biological data from 1,480 shells with environmental estimates, enabling analyses of spatial trends and ecological drivers of predation.

Contents

R Scripts

This repository includes a single R script that reproduces Figures 3 to 6 from the study, detailing:

Figure 3: PCA of oceanographic variables

Figure 4: Latitudinal trends of individual oceanographic variables and PCA scores

Figure 5: Latitudinal and biogeographic variation in crushing predation frequency

Figure 6: Intrinsic and extrinsic drivers of ...,