Resolution of ambiguous taxonomy of ascidians reveals high levels of introductions of invasive species at the SW Atlantic

TATIAN, MARCOS; GIMENEZ, DIEGO; SCHWINDT, EVANGELINA; ALURRALDE, GASTON; LAGGER, CRISTIAN; TAVERNA, ANABELA; GIACHETTI, CLARA; MAGGIONI, TAMARA

Buenos Aires

Congreso; MFIS Marine & Freshwater Invasive Species. Ecology, Impact and Management; 2016

Acquatic Ecosystem and Health Management Society/CONICET

One of the poorly known regions in terms of its biodiversity, in particular in the case of ascidians, is the Southwestern Atlantic (SWA). Ascidiacea is one of the main groups in bioinvasion studies given that are good indicator of anthropogenic transport and because they are usually very abundant in terms of richness. The accurate species identifications are crucial to clarify causes and consequences of the invasion processes. The aim of this work was to determine species richness and, especially, to report those species considered as exotic and cryptogenic together with its present distribution along the SWA. We performed different field sampling at the SWA including coastal areas (natural and harbour localities) and oceanic areas. We also exhaustively studied old museum collections, and the specific taxonomic and global literature that helped us to elucidate the status of native, cryptogenic or exotic in the area. The general survey of species revealed, at the moment, a total of 80 ascidian species, being 18% of them, species whose status is considered exotic and/or cryptogenic. The use of morphological and genetic tools to clarify the species identity is the first step into the evaluation of invasion processes and this would help to better understand the real scenario in terms of native biodiversity.