First record of the solitary ascidian Ciona savignyi Herdman, 1882 in the Southern Hemisphere

This report documents the first recording of the solitary ascidian Ciona savignyi in the Southern Hemisphere. Adult tunicate specimens were collected from the Nelson city marina (South Island, New Zealand) in April 2010. Both mitochondrial cytochrome oxidase I (COI) gene sequences and morphological characters were used to identify the tunicates as C. savignyi - the first report of this species in New Zealand and the Southern Hemisphere. This study highlights the power of molecular methods for invasive species identification and New Zealand's need for an extensive, systematic molecular inventory of its existing marine invertebrate biodiversity.