Relative warps and Correlation Analysis based on Distances of the morphological shape of the shell of the golden apple snail Pomacea canaliculata from Iligan city, Philippines

Abstract

Relative Warp Analysis and Correlation Analysis based on Distances (CORIANDIS) were used to study morphological variations in the shape of the snail P. canaliculata, an invasive pest species of rice agroecosystem. Relative warps are factors (principal components of partial warp scores) which summarize the major vectors of shape variation within samples. Correlation Analysis based on distances on the other hand, allows both looking into similarities among specimens/groups, and interpreting such similarities in terms of congruence among traits. It is also a measure of trait disparity. Comparison of samples was done by looking into the relative contributions of different traits to each species groups' distinctiveness. Results have shown close resemblance or association in terms of shell shape between populations of female and male individuals. Results obtained have somehow, demonstrated that subtle shape differences in shell shape can be detected by geometric morphometrics.