Invasion of Corbicula spp. in Argentina: Phenotypic plasticity of a global invasive bivalve

HUNICKEN, LEANDRO; PAOLUCCI, ESTEBAN; FRANCISCO SYLVESTER

Buenos Aires

Conferencia; Marine and Freshwater Invasive Species Conference- MFIS; 2016

MACN-CONICET y Aquat. Ecosyst. Health Manage

Invasive freshwater bivalves are a group of special concern because of its rapid expansion and wide range of effects. Freshwater clams in the genus Corbicula, native to Southeast Asia, began to expand globally in the early last century. In Argentina, the genus was introduced through Río de la Plata in the 1970s, and 50 years later has achieved a countrywide distribution across a diversity of aquatic habitats. An important adaptation mechanism is phenotypic plasticity. Changes in the morphology of the shell, gills, and labial palps have been reported for other invasive bivalves such as the golden mussel as a response to new environmental conditions in habitats colonised. In this study, we compare the morphology of six invasive Corbicula populations across the provinces of Salta, Córdoba, Catamarca, Buenos Aires and Río Negro in Argentina. We used 20 individuals per site to calculate gill area/valve area (GV); palp area/valve area (PV); and palp area/gill area (PG) ratios for these populations. We conducted analyses of covariance to examine differences between these morphometric relationships, using clam size (surrogate for age) as a covariate. All ratios showed significant differences among populations (GV: F(5,121) = 12.05, PV: F(5,108) = 12.72, p PG: F(5,108) = 15.00; p