First register of the invasive ascidian Asterocarpa humilis in the SW Atlantic.

TAVERNA, A; MAGGIONI, T.; REYNA, PAOLA; ALURRALDE G; GIMÈNEZ, D; TATIÁN, M.

Buenos Aires

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

REABIC

The ascidian Asterocarpa humilis (Heller, 1878), (Tunicata, Chordata), native from New Zealand, has expanded its original range of distribution being considered exotic in remote areas such as Chile, South Africa and more recently, Great Britain and France. Until now it had not been observed in Argentina. A similar species (considered synonym of it by Kott, 1985), Cnemidocarpa robinsoni Hartmeyer, 1916 is native from the Juan Fernández archipelago. That species, was reported in the Southwest Atlantic (Diehl 1977) remaining uncertain its status for the area. The examination of morphological characters in abundant material from different localities of Argentina (i.e.: the number of oral tentacles, the amount and form of the gonads, the location of the gonoducts and the prescence of larvae) showed similarities with those described for A. humilis (Clarke and Castilla., 2000; Bishop et al 2013) being more relevant the orientation of gonoducts and the presence of larvae. The name Asterocarpa humilis has precedence over Cnemidocarpa robinsoni, so the latter should be discarded. The absence of true records prior to the description of Diehl and its current wide distribution, particularly in port areas, affirms the exotic status of A. humilis in the SW Atlantic.