A new species of<i>Temnocephala</i>(Platyhelminthes, Temnocephalida) and a description of<i>T. axenos</i>from Uruguay

Abstract

In Uruguay, two species of Temnocephala Blanchard, 1849 have been reported on the anomuran crab Aegla Leach, 1920, namely Temnocephala axenos Monticelli, 1899 Monticelli, F. S. 1899. Sulla Temnocephala brevicornis Monticelli, 1889 e sulle temnocephale in generale.. Bolletino della Societa Naturalisti Napoli, 12: 72–127. [Google Scholar] and Temnocephala talicei Dioni, 1967. A third species, described here as Temnocephala mertoni n. sp., has been found on Aegla platensis Schmitt, 1942 from southern Uruguay. The new species resembles T. talicei, but differs by having a penial stylet with a sinuous distal portion of the shaft; a small introvert with short, distal spines, and a discrete thickening in its wall. The penial stylet of T. mertoni n. sp. is more similar to that of T. axenos. In view of the importance of stylet structure and shape in the taxonomy of this group, a description of T. axenos is included, and a comprehensive study has been carried out to establish the differences between these species. Based upon this study, new characters are proposed for the taxonomy of the genus Temnocephala.