Bostricobranchus digonas Abbott (Ascidiacea, Molgulidae) in Paranaquá Bay, Paraná, Brazil: a case of recent invasion?

Abstract

Bostricobranchus digonas Abbott, 1951 was discovered by dredging near Cotinga Island, Paranaguá Bay, Paraná (25º31'511"S, 48º28'714"W). Concentrated in a small area 1.5 m deep, the animals were collected by a Van Veen device. All sizes from 3 mm up to 2 cm in body diameter were recovered. This is the first report of a species of this genus in the South Atlantic and its oeeurrenee is diseussed.