Evolutionary mechanisms underlying a shell color cline in Littorina saxatilis (Olivi, 1972)

• Autores: Ramón Vigo Quintero
• Directores de la Tesis: Emilio Rolán Álvarez (dir. tes.), Juan Galindo Dasilva (dir. tes.)
• Lectura: En la Universidade de Vigo ( España ) en 2026
• Idioma: inglés
• Programa de doctorado: Programa de Doctorado en Metodología y Aplicaciones en Ciencias de la Vida por la Universidad de Vigo
• Materias:
  • Ciencias de la vida
    • Biología animal (zoología)
      • Zoología marina
• Enlaces
  • Tesis en acceso abierto en: Investigo
• Resumen

  • Marine snails of the genus Littorina are highly polymorphic for many morphological and physiological characters. In Littorina saxatilis, one of the most polymorphic marine snail species, a cline or gradual variation of shell color has been described along the Ría de Vigo with a dominance of light colors such as fawn-like (fulva), yellow (lutea) or light brown (fusca) towards the interior of the estuary and darker colors or line pattern (lineata) in the outermost localities. This gradual variation is also suggested in other Rías Baixas such as Muros e Noia or Pontevedra. Previous studies exclude that this distribution could be explained by vicariant, historical or genetic drift effects, so the approach of this project is to prove the role of natural selection in the maintenance of this cline. Furthermore, many of these populations show intra-population color polymorphisms associated with the spatial heterogeneity of their different microhabitats, which could be related to heterogeneous selection events due to crypsis strategies. Once verified that the color cline of this species in the Ría de Vigo remains relatively stable after at least half a century, it has been proposed different selective pressures that could be involved. This doctoral thesis project aims to design and conduct different experiments both in the laboratory and in situ to confirm or reject the influence of factors such as a preference for a particular habitat based on the substrate coloration, different morphs chosen for mating, and environmental factors such as a thermal gradient along the cline.