Disruptive camouflage through three-dimensional shapes and serrated edges in vertebrates
Description
Disruptive coloration reduces visual detection or recognition by breaking up the animal’s body shape by using contrasting patterns. However, this effect could also be produced by specific shape or morphological features, sometimes termed ‘irregular marginal form’, or three-dimensional (3-D) features, although this has rarely been studied. The keeled box turtle (Cuora mouhotii) has a uniformly colored carapace but subjectively demonstrates substantial disruptive efficiency. Although speculated to result from its unique shell shape, this has not previously been confirmed experimentally. Here, we used 3D technology to isolate the effects of unique shape features and measured the level of body outline disruption through image analysis of edges. Compared with a normal 3D C. mouhotii shell model, the lowest Gabor edge disruption ratio (GabRat) was observed following removal of the central protruding keel, followed by the addition of serrated carapace edges. Compared with a 2D model, unique depth cues (carapace height) in the 3D model had minimal overall effect on GabRat; however, they increased GabRat of the 3D-protruding keel substantially. Flattened scutes along the carapace top had little effect on GabRat. Disruption was primarily achieved by the 3D-protruding keel disrupting the smooth carapace surface, with depth cues further enhancing the effect, resembling edge enhancement. Serrated edges further disrupted the carapace outline. This study provides empirical evidence that 3D shapes alone can enable disruptive camouflage in vertebrates, offering theoretical support and insights into turtle conservation and advanced camouflage technology development. --------------------General Information------------------- #Date of data collection September 2024 to April 2025 #Location of data collection PR China --------------------Overview for data------------------- #File List: 1_GabRat Data: This file contains the GabRat values measured for the processed models under three visual systems, as well as the body size parameters of each specimens. 2_Spectral Data:This file contains the spectral data of the carapace coloration for both keeled box turtle and Indochinese box turtle specimens and models. --------------------Methodological Information------------------- #Data was processed/analyzed with RStudio (version 2024.04.1+748).