Combined methods to detect pollution effects on shell shape and structure in Neogastropods

FEDERICO MARQUEZ; GREGORIO BIGATTI; GONZÁLEZ-JOSÉ, ROLANDO

ECOLOGICAL INDICATORS

ELSEVIER SCIENCE BV

Año: 2011 vol. 11 p. 248 - 254

1470-160X

Tributyltin (TBT) has been widely used as antifouling in marine environments, producing imposex ingastropod females (i.e. neoformation of a vas deferens and/or a penis) and shell malformations in bivalves.However, effects of TBT and other pollutants from high marine traffic zones on the shell of gastropodshave been little explored. Shell shape in volutids Odontocymbiola magellanica from a harbor pollutedsite (P) has been compared with that of animals from a non-polluted location (NP) using 3D geometricmorphometrics. Also, the microstructure and density of shells from both populations were analyzed.Prior studies made in the same area (Golfo Nuevo, Patagonia, Argentina) based on traditional multivariatemorphometricsshowedsomedifferences in size butwasunable to detect differences in shell shapeamongO. magellanica from P and NP areas. Departing from 3D geometric morphometrics, scanning electronmicroscopy (SEM) and computed tomography (CT) techniques, we have registered the presence of patentdifferences on shell shape and structure in animals from polluted (P) and non-polluted (NP) areas. In100% of shells from the NP area we register three calcium carbonate layers (prismatic, cross lamellar andamorphous) and higher densities, while in 50% of the shells collected at the P area the external layer(amorphous) was lacking. Furthermore, a body weight loss of around 30% and a shell weight loss of 20%were registered in animals from the P area. Our combined results suggest that the coordinated use of3D geometrics morphometrics, CT scan and SEM could be of great utility in order to detect the effect ofenvironmental variables on Neogastropods shell shape and structure.