Pinna rapanui n. sp (Bivalvia: Pinnidae): The Largest Bivalve Species from Easter Island, South Pacific Ocean, Chile

Abstract

A new bi valve spe cies of the ge nus Pinna Linnaeus, 1758, is de scribed from shal low wa ter off the coast of Eas ter Island, south east ern Pacifi c Ocean. Pinna rapanui sp. n. has a small, broad, slightly angulated shell with a sculp ture of commarginal growth lines and prominent ra dial ribs dec o rated by al most tubu lar, per pen dic u larly erect spines. This spe cies is the 249th ma rine mol lus can spe cies found in Eas ter Island wa ters, and it is, by far, the larg est bi valve spe cies liv ing around the island. A Poly ne sian or i gin of this spe cies is suggested; howev er, its defi nite af fi n i ties with Indo - Pacifi c or South Amer i can fauna are still un known.