Three new species of Polycladida from Argentina

BULNES V.N.; ALBANO M.J.; OBENAT S.M.

Diepenbeek (Belgium)

Simposio; XI INTERNATIONAL SYMPOSIUM ON FLATWORM BIOLOGY. Formerly International Symposium on the Biology of Turbellaria. 3rd INTERNATIONAL MACROSTOMUM MEETING Diepenbeek (Belgium) 26 July - 31 July 2009.; 2009

Three new species of Polycladida were collected from Mar del Plata Harbour, Buenos Aires, Argentina. One species belongs to the genus Pseudoceros Lang, 1884, which is characterized by the presence of marginal tentacles, a ruffled pharynx, a true seminal vesicle, a free prostatic vesicle and penis papilla armed with a stylet. T'he other two species belong to the genus Thysanozoon Grube, 1840, which is characterized by the presence of dorsal papillae, marginal tentacles, a maje reproductive system with paired copulatory organs with true seminal vesicles, a free prostatic vesicle and penis papillae, each of them armed with a stylet. The specific determination in both genera is based on the colour and colour pattern, but, due the known ecological variability, a detailed account on their anatomy was made. This is the fourth citation for species belonging to genera that were previously known for tropical waters and now reported as living in temperate cold regions. Mar del Plata is one of the most important harbours in the country due to ship traffic and commercial trade, and it was impossible to verify if the described species are endemic or if this is a possible case of trans-oceanic dispersal of fouling organisms on ships.