CARACTERIZACIÓN MORFOMÉTRICA Y ESTRUCTURAL DE LAS LAPAS COSTERAS Nacella concinna (Nacellidae) ENCONTRADAS EN LA ESTACIÓN ANTÁRTICA ECUATORIANA

Abstract

This study examines the most abundant species of mollusks found at the Pedro Vicente Maldonado Antarctic Station: the Nacella Polaris limpets. Evidence was collected during the XXI expedition. Transects and plots were established, and shells were analyzed by morphometric characterization and scanning electron microscopy (SEM). The morphometry of limpets was variable with a range of 22.880 ± 53.920 mm. Eighty-five point six percent of the limpets were large, and these were found mainly in the Whale Cemetery. On the other hand, the smaller ones were found mostly in the Sleeping Lion area, and account for 1.36% of the sample.  The following characteristics were observed on their lower outer rim: transverse, linear to slightly wavy striations with defined thicknesses, a crystalline ultrastructure with linear, slightly wavy, surface growth lines, and ladder-shaped calcite columns supporting the growth lines. Morphometric and ultramicroscopic data for the shells indicate that their external architecture is analogous. The population examined behaves as a single population and exhibits slight size polymorphism. In addition, microstructural patterns have been observed in the outer layers of the shells.