Introduced Ascidians in Paranagua Bay, Parana, southern Brazil

Exotic (introduced) species are a growing problem in ports worldwide and comprise the most important impacts in marine ecosystems. Periodic monitoring to detect introduced species is extremely important for effective population control. Here we sampled ascidian species near the port of Paranagua for a taxonomic study of this fauna to attempt to detect introduced species. Larval stages in ascidians are short-lived, and dispersal is restricted to small distances, and so ascidians are very good bioinclicators for exotic introductions due to ship transport. Four locations were sampled within Paranagua Bay (IIha das Cobras, Pier Tenenge, IIha do Mel and IIha da Galheta) and one location outside of the bay (Parque dos Meros). Information for the nearby fauna and for geographic distributions of the species involved was obtained from the literature. Eighteen species were found: Perophora multiclathrata (Sluiter, 1904), Ascidia curvata (Traustedt,1882), A sydneiensis Stimpson, 1855, Clavelina oblonga Herdman, 1880, Cystodytes dellechiajei (Della Valle, 1877), Eudistoma carolinense van Name, 194S, Distaplia bermudensis van Name, 1902, Didemnum granulatum Tokioka, 19S4, Diplosoma fisterianum (Milne-Edwards, 1841), Lissoclinum fragile (van Name, 1902), Bottyllus planus (van Name, 1902), B. tuberatus Ritter ex Forsyth 1917, Botrylloides n1grum Herd man, 1886, Symplegma rubra Monniot,1972,Styela canopus (Savigny,1816),S. plicato(LesueLir,1823),Microcosmus exasperatus Heller, 1878 and Molgula phytophila Monniot, 1970. The known geographic distributions based on the literature and collections suggest that three species are native, one is a inter-regional introduction, two are introduced from the Pacific and the remaining 12 are cryptogenic.