The freshwater ribbon-worm Prostoma graecense (Hoplonemertea: Monostilifera) in South America (Argentina)

Abstract

The morphological species Prostoma graecense (Böhmig, 1892) is reported for the first time fromArgentina and South America. Some diagnostic characters, such as the ciliated epithelium of thenon-rhynchodaeal oesophagus and the backward extension of the cephalic glands up to the braincommisure, were confirmed for the Argentine material; the rhynchodaeal longitudinal muscleswere present, but did not form a thick layer as expected from some previous descriptions. AddingSouth America to its distribution range supports the hypothesis that this morphotype Prostomagraecense actuallyhas a cosmopolitan distribution.