Zoological Studies

Vol. 62, 2023

(update: 2023.5.26)

A New Polyclad Flatworm, Idiostylochus tortuosus gen. nov., sp. nov. (Platyhelminthes, Polycladida) from France. Can this Foreign Flatworm be Responsible for the Deterioration of Oyster and Mussel Farms?

Adrian Gutiérrez1, Isabelle Auby2, Benoit Gouillieux3, Guillemine Daffe3, Cecile Massé4, Elvire Antajan2, and Carolina Noreña1,*

1Departamento de Biodiversidad y Biologia Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), C/ Jose Gutierrez Abascal 2, 28006 Madrid, Spain. *Correspondence: E-mail: norena@mncn.csic.es (Noreña).
E-mail: adrgut01@ucm.es (Gutiérrez)
2Ifremer, LITTORAL, Quai Du Commandant Silhouette, 33120, Arcachon, France. E-mail: Isabelle.Auby@ifremer.fr (Auby); Elvire.Antajan@ifremer.fr (Antajan)
3Univ. Bordeaux, CNRS, Observatoire Aquitain des Sciences de l’Univers, UAR 2567 POREA, F-33615, Pessac, France. E-mail: benoit.gouillieux@u-bordeaux.fr (Gouillieux); guillemine.daffe@u-bordeaux.fr (Daffe)
4Service Patrimoine Naturel (PATRINAT) OFB, CNRS, MNHN, CP41, 36 rue Geoffroy Saint-Hilaire 75005 Paris, France. E-mail: cecile.masse@mnhn.fr (Masse)

(Received 19 March 2022 / Accepted 18 January 2023 / Published 26 May 2023)
Communicated by Benny K.K. Chan

A new species of polyclad flatworm, Idiostylochus tortuosus gen. nov., sp. nov. (Polycladida, Idioplanidae), from Arcachon Bay (France) is described. This description is based on a morphological analysis and a molecular analysis using partial sequences of the 28S and cytochrome Oxidase I (COI) genes. After the molecular analysis Idiostylochus gen. nov. appears to be the second genus of the Family Idioplanidae and
closely related to the family Latocestidae as well as the genera Leptostylochus and Mirostylochus. The molecular data revealed that the new species may belong to an Indonesian or Indo-Pacific family, closely related to genera with origins in South Pacific Ocean waters. This species was found feeding on the oysters and mussels of the Arcachon farms.

Key words: Acotylea, Idioplanidae, non-native species, Magallana gigas, oyster culture.

Citation: Gutiérrez A, Auby I, Gouillieux B, Daffe G, Massé C, Antajan E, Noreña C. 2023. A new polyclad flatworm, Idiostylochus tortuosus gen. nov., sp. nov. (Platyhelminthes, Polycladida) from France. Can this foreign flatworm be responsible for the deterioration of oyster and mussel farms? Zool Stud 62:15. doi:10.6620/ZS.2023.62-15.