Folia Parasitologica 67:033 (2020) | DOI: 10.14411/fp.2020.033

New type of xiphidiocercariae (Digenea: Microphalloidea) from South Vietnam

Darya Krupenko¹, Anna Gonchar^1,2, Georgii Kremnev¹, Boris Efeykin^3,4,5, Vladimir Krapivin^1,3,4

¹ Saint Petersburg University, Department of Invertebrate Zoology, Saint Petersburg, Russia;

² Zoological Institute, Laboratory of Parasitic Worms and Protists, Russian Academy of Sciences, Saint Petersburg, Russia;

³ Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia;

⁴ The Russian-Vietnamese Tropical Scientific and Technological Centre, Southern Branch, Ho Chi Minh, Vietnam;

⁵ Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia

We found unusual digenean intramolluscan stages, sporocysts and cercariae, in gastropods Sulcospira dautzenbergiana (Morelet) (Caenogastropoda: Pachychilidae) from Southern Vietnam and named them Cercaria cattieni 1. These cercariae have a stylet and thus belong to the Xiphidiata. However, such combination of characters as extremely large body size and I-shaped excretory bladder has not been found before in any other xiphidiocercariae. We obtained COI, ITS1, 5.8S + ITS2, and 28S rDNA sequences for C. cattieni 1. The latter allowed us to specify the phylogenetic position of the discovered cercariae: C. cattieni 1 falls within the superfamily Microphalloidea and is most closely grouped to Pachypsolus irroratus (Rudolphi, 1819) (Pachypsolidae), the sea turtle parasite. Information on the family Pachypsolidae is limited. Judging from the molecular phylogeny, C. cattieni 1 might be the larva of the Pachypsolidae, documented for the first time.

Keywords: Digenea, xiphidiocercariae, sporocysts, Xiphidiata, Microphalloidea, Pachypsolidae, 28S rDNA, ITS1, ITS2, COI

Received: February 5, 2020; Revised: August 15, 2020; Accepted: September 1, 2020; Published online: November 27, 2020  Show citation