Syndesmis aethopharynx (Umagillidae, Rhabdocoela, Platyhelminthes) from the sea urchin Paracentrotus lividus: first record from the Eastern Mediterranean, phylogenetic position and intraspecific morphological variation

Abstract

Specimens of Syndesmis aethopharynx Westervelt & Kozloff, 1990 (Umagillidae, Rhabdocoela, Platyhelminthes) were collected from the intestine of several specimens of the sea urchin Paracentrotus lividus (Lamarck, 1816) Hansson, 2001 at the Greek coast. This 26 represents the first report of a species of Syndesmis from Greece. Our study has revealed several previously-unreported morphological details and intraspecific variation, which are added to the species description. The position of S. aethopharynx within Umagillidae is confirmed for the first time through molecular data (based on nuclear 18S rDNA), using both Bayesian and maximum likelihood analyses.