Sexual dimorphism in apple snails shell shape: is Pomacea canaliculata an exception or an example?

TAMBURI N.; TIECHER M.J.; BURELA S.; MARTIN P.R.

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2021

0001-3765

Sexual dimorphism has often been recorded in apple snails (Caenogastropoda Ampullariidae), butreports are concentrated in a few species, either invasive or with biocontrol potential, which sugests sometaxonomic bias. To find out evolutionary and ecological correlates of sexual dimorphism it is necessary todetect and quantify it but also is important to detect its absence. Our aims were to confirm or not theexistence of sexual dimorphism in shell and operculum shape of Felipponea neritiniformis and Asoleneplatae, using Pomacea canaliculata as reference and applying the same methodology (landmark-basedgeometric morphometrics) and statistical power. Significant intersexual differences were only found in P.canaliculata and, in a lesser degree, in F. neritiniformis: males have larger apertures relative to body whorland more rounded apertural outer edges. Sexual dimorphism in operculum curvature was detected only inP. canaliculata. Female shells are larger in F. neritiniformis and P. canaliculata, but not in A. platae.Using comparable methodologies and statistical power, sexual dimorphism in shell shape is detectable insome apple snails but not in others. Interspecific variation in sexual dimorphism in the Ampullariidae isnot only due to taxonomic bias and deserves more research to establish the main patterns and possiblecauses.