IDEAUS - CENPAT   25626
INSTITUTO DE DIVERSIDAD Y EVOLUCION AUSTRAL
Unidad Ejecutora - UE
artículos
Título:
Allometric differences on the shell shape of two scorched mussel species along the Atlantic South American Coast
Autor/es:
ROLANDO GÓNZALEZ-JOSÉ; ADAMI, MARIANA L.; NIETO-VILELA, ROCÍO A.; MÁRQUEZ, FEDERICO; TROVANT, BERENICE
Revista:
EVOLUTIONARY ECOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2018 vol. 32 p. 43 - 56
ISSN:
0269-7653
Resumen:
Scorched mussels (Bivalvia: Mytilidae) are an important component of rockyshore assemblages around the world. The mussel beds of the mid-intertidal coasts of thesouth-western Atlantic are composed of two species of scorched mussels, which dominatethe physiognomy and structure of the rocky shore communities. The present studyinvestigates the variation in the shell-shape allometric trajectories of both species ofmussels throughout their distributional range in the southwestern Atlantic coast, fromlatitude 34°S to 53°S. Shells of Brachidontes rodriguezii were collected at two Uruguayanlocalities and four Argentinean localities, while shells of Perumytilus purpuratus werecollected at six Argentinean localities. Shell shapes of the specimens were studied bygeometric morphometrics using landmark and semi-landmark methods. Different evolutionaryhistories and thermal regimes characterize these two species. Brachidontesrodriguezii seems to have a long history in the region and is present in a restricted area, thewarm temperate region of the south-western Atlantic, while P. purpuratus seems to have arecent history and is present in a wide thermal range, involving the cold-temperate regionsof the south-western Atlantic and south-eastern Pacific and the warm-temperate region ofthe south-eastern Pacific. Based on these considerations, we prompt the hypothesis thatallometric trajectories of P. purpuratus shell shape is more variable and adapted to aspecific habitat than B. rodriguezii. The impact of allometry was larger in P. purpuratusthan in B. rodriguezii. Graphical evidence was gathered, showing that these two speciesdiffer in allometric growth forms and that the allometric shell morphology changes reflectenvironmental constraints and adaptation. While the intertidal mussel beds of the SouthAmerican coasts are ecologically similar in appearance, we found that the allometricvariation of the scorched mussels occurs in response to diverging evolutionary processessuch as phenotypic plasticity in P. purpuratus and canalization in B. rodriguezii.