The body size has always been the focus of several ecological studies due to its undeniable influence on other life history features. The conventional representation of the body size in the arthropods is generally based on linear measures, such as the total length of the body, or the length of the specific body parts that can be used to represent the size of the body. While these measures offer simplicity about more complicated alternatives (e.g., Dry mass), technical problems persist for arthropods with complex body structures, such as scorpions. In these animals, precise measurements often require extensive handling, including stretching body parts. In light of the difficulties associated with the direct measurement of the total length and the length of the shell in the scorpions (two prevalent proxies for the size of the body in the group), this study evaluates the capacity of seven simple linear measurements in the prediction in the prediction of measures of the size of children in scorpions under a phylogenetic structure. The predictive equations derived from the mixed phylogenetic mixed models adjusted under the Bayesian framework were implemented in personalized R functions that can be applied for size prediction in a wide range of scorpions. In general, the precise predictions of the total length and length of the shell could be achieved using any of the traits studied as individual predictors. However, the most precise predictions for the total length were obtained using the length of the Metasomal V segment, while the best predictions for the length of the shell were achieved using the length of Telson. The addition of a secondary predictor had a low impact on the quality of size predictions, indicating that increasing the complexity of the model by incorporating additional predictors is not necessary to achieve precise size estimates. The advantages and technical limitations associated with each linear measurement are discussed. In conclusion, this study expands the repertoire of methods available to accurately estimate the body size in scorpions, particularly in cases where body size information can only be obtained indirectly through alometric relationships.
Foerster Sía. 2025. Prediction of the body size in scorpions: a comparative phylogenetic examination of linear measurements of individual body parts. Peerj 13: E18621 https://doi.org/10.7717/peerj.18621
#phylogenetic #comparative #examination #linear #measurements #individual #parts #body
