Two new species of Syndesmis (Platyhelminthes, Rhabdocoela, Umagillidae) from the sea urchin Pseudechinus magellanicus (Echinodermata, Echinoidea) in the Southwestern Atlantic Ocean. (NOTA:IDEM PAPER RIGGIA)

MONTES MARTIN MIGUEL; BRUSA FRANCISCO; MARCOTEGUI PAULA; MONTES MARTIN MIGUEL; MARTORELLI SERGIO; BRUSA FRANCISCO; MARTORELLI SERGIO; MARCOTEGUI PAULA

International Journal for Parasitology: Parasites and Wildlife

Elsevier

Año: 2017 vol. 6 p. 54 - 58

2213-2244

In this paper we described two new species of Syndesmis living in Pseudechinus magellanicus in the Southwest Atlantic. The new species have a long stylet in the male reproductive system different to the known species of the genus. Syndesmis selknami n. sp, have a stylet of ~220 µm length (1/3 of the body length). This ratio is unique because only four species (Syndesmis echinorum, Syndesmis rubida, Syndesmis inconspicua and Syndesmis echiniacuti) have similar stylets length but they are bigger in body sizes (3 to 5 mm). Syndesmis aonikenkis n. sp. has a stylet ~148 µm long (~1/10 of body length). Syndesmis pallida has a similar ratio but the uterus is located posteriorly, the filament glands are very small and located in the posterior region of the body. These are the first flatworm reported parasiting Pseudechinus magellanicus.