INALI   02622
INSTITUTO NACIONAL DE LIMNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Shape variations between populations of Aegla uruguayana (Crustacea, Decapoda, Anomura). A phenotypic plasticity case?
Autor/es:
GIRI, F.; COLLINS, P.
Lugar:
New York
Reunión:
Congreso; Evolution 2006; 2006
Institución organizadora:
Stony Brook University’s Department of Ecology and Evolution
Resumen:
The freshwater crabs Aegla uruguayana occurs in dissimilar habitats, from large to small rivers, as well as ponds, shallow lakes and mountain streams running waters. It is present in Uruguay, center of Argentina and South-East of Brazil. Phenotypic plasticity, “the property of a given genotype to produce different phenotypes in response to environment influences”. Plasticity has an important role in the polyphenism evolution, particularly regarding the adaptive response to temporal and spatial heterogeneity of the abiotic environment. Consequently, our interest is to analyze if intraspecific shape variations at population level of A. uruguayana is a result of phenotypic plasticity. A total of 438 individuals from 20 populations from different sub-basins were studied. Digital pictures of the cephalothorax were taken. A total of 17 landmarks were obtained and digitized as a result of a symmetrization process. Sexual dimorphism analysis did not reveal shape differences. PCA revealed differences among sub-basins individuals (axes 1 and 2 show 47.5% of the variation, this result was supported by MANOVA, p< 0.0001). Differences were observed mainly as wider cephalothorax and a shorter rostrum in the Maldonado specimens. Also, the anterior part of the body was longer to the detriment of the posterior region in contrast with La Plata sub-basins specimens. As a conclusion, A. uruguayana is likely to present phenotypic plasticity if we consider the populations related, as seen among the La Plata sub-basin specimens. However, the differences in shape observed could also be due to variations in genotype which are manifested in the crab’s phenotype.