Intra-Specific Variability in Whorl Growth-Rate among Land Gastropods with Conispirally-Coiled Shells

For most conispirally-coiled Gastropods with determinate growth, the geometry of spirally-winding whorls is usually constrained by a strong negative correlation between whorl growth rate and number reached at adulthood, as originally reported late S.J. Gould. Yet, beyond tight control shell-shape species level – resulting from this constraint what about amplitude intra-specific variability growth-rate, partly contributing to overall shell-size level? I address issue designing implementing new, indirect method for routinely evaluating thereby aiming considerably saving measurement time, making it possible easily achieve repeated measurements across samples large enough reach statistical significance. This approach was applied series eight common land snail species. The in evaluated way, proves: (i) being markedly different among investigated (by factor that can exceed 2x); (ii) being, yet, high enough, all cases, require compensating variations adult whorls, so limit consequences on shell-size. Despite those marked differences amplitudes growth-rate species, no significant relationship observed intraspecific species-specific types (discoidal/globular/elongate) only weak positive typical shell sizes. However, rather found, expected, degree adulthood (with yet unexplained exception one species).