INFERRING THE CONNECTIVITY BETWEEN HABITATS FOR Menticirrhus americanus IN THE SOUTHWESTERN ATLANTIC COAST: AN APPROACH BASED ON OTOLITH CONTOUR.

MAICHAK DE CARVALHO, BARBARA; VOLPEDO, ALEJANDRA V.; AVIGLIANO, ESTEBAN; LUIS FÁVARO; J. L OTERO-FERRER; VICTOR TUSET

Workshop; INFERRING THE CONNECTIVITY BETWEEN HABITATS FOR Menticirrhus americanus IN THE SOUTHWESTERN ATLANTIC COAST: AN APPROACH BASED ON OTOLITH CONTOUR.; 2019

The aim of the present study was to analyze the otolith phenotypic variability between the specimens of Menticirrhus americanus inhabiting estuaries and the continental shelf from the Southwest Atlantic Ocean. A total of 279 otoliths were collected and analyzed from three latitudes (23°S, 25°S and 26°S), of which 173 otoliths belonged to estuaries areas (total length mean SD, 32.0 3.7 cm) and 106 otoliths to continental shelf (28.9 4.6 cm). The contour analysis was performed using wavelet transformed at 4thscaleon 512 equidistant Cartesian coordinates, being the anterior margin the contour origin. A principal component analysis (PCA) was performed to avoid collinearity between the shape descriptors, and the effect of total length was removed using the residuals of the common within-group slopes of the linear regressions of each component on otolith length.The PERMANOVA analysis did not indicate significant differences linked to sex and latitude, but showed variations associated with the habitat. The Canonical Variate Analysis (CVA) correctly classified 73.9% of the otoliths for the estuarine environment and 62.2% of the otoliths for the continental shelf. It suggests that otoliths from specimens of estuaries zones are clearly different of the continental shelf. Our hypothesis is that a partial fraction of estuaries population may have a short-range homing, whereas other ones may have larger movements towards the continental shelf.