Mollusca, Bivalvia, Isognomon bicolor (C. B. Adams 1845): Distribution extension

The bivalvia species Isognomon bicolor (C. B. Adams 1845) was first recorded on the Brazilian coast by Domaneschi and Martins (2002). I. bicolor is an exotic invasive species, possibly introduced into Brazil accidentally on oil or gas platforms from the Caribbean coast. A recent spatially isolated study has recorded the species in Brandao Island at Ilha Grande Bay (Moyses et al. 2007). As part of a large marine biodiversity project carried out in 2003, 37 locations were visited in the Ilha Grande Bay and the general distribution of I. bicolor at each location was mapped by two SCUBA or snorkel divers, which spent five periods of 1 min underwater, subjectively evaluating its presence or absence.