# Morphometric Traits as Predictors of Body Mass in the Marine Gastropod Semicassis bisulcatum: Insights for Aquaculture and Selective Breeding

## TL;DR

This study identifies key shell traits in the marine snail Semicassis bisulcatum that predict body mass and soft tissue yield, aiding aquaculture and breeding efforts.

## Contribution

The study establishes the first phenotypic framework for selective breeding in Semicassis bisulcatum using morphometric predictors of body mass and soft tissue yield.

## Key findings

- Shell thickness is the strongest predictor of total body mass in Semicassis bisulcatum.
- Shell width is most closely associated with soft tissue yield in the species.
- Combined shell thickness and height best predict body mass, while shell width and aperture height best predict soft body mass.

## Abstract

The gastropod Semicassis bisulcatum represents a promising candidate for aquaculture. However, essential biological data for establishing selective breeding programs are still lacking. This study quantified morphological and mass traits in wild populations and revealed that mass-related traits, with soft body mass being the most notable, show substantially greater individual variation than morphological traits. This finding indicates significant potential for genetic improvement. Shell thickness was identified as the strongest predictor of total body mass, while shell width was most closely associated with soft tissue yield. These relationships provide concrete breeding guidance, suggesting that selecting for thicker shells enhances overall biomass, whereas prioritizing wider shells improves soft tissue production. This work establishes the first phenotypic framework for selective breeding in this species, supporting its sustainable aquaculture development.

The marine gastropod Semicassis bisulcatum, valued for its ornamental shell and edible soft tissue, lacks essential biological data for selective breeding. This study was conducted on 100 wild individuals collected from the Beibu Gulf to identify key morphological traits influencing body mass (BM) and soft body mass (SBM). Both mass traits showed high variability (SBM CV = 41.04%; BM CV = 23.88%), indicating strong breeding potential. Path analysis revealed that shell thickness (ST) exhibited the strongest direct association with body mass (path coefficient = 0.509), while shell width (SW) was most closely linked to soft body mass (path coefficient = 0.482). The combined coefficient of determination confirmed that shell thickness (ST) and shell height (SH) together were the strongest predictors for body mass. Similarly, Shell width (SW) and aperture height (AH) together had the strongest combined effect on soft body mass. These findings provide a critical morphological basis for future selective breeding programs.