Mikrocytos donaxi Garcca & Haond & Chollet & Nerac & Omnes & Jols & Dubreucl & Serpcn & Langlade & Gal & Terre-Terrcllon & Courtocs & Gucchard & Arzul 2018, n. sp.
Creators: name: Garcia, Céline
name: Haond, Christophe
name: Chollet, Bruno
name: Nerac, Mirella
name: Omnes, Emmanuelle
name: Joly, Jean-Pierre
name: Dubreuil, Christine
name: Serpin, Delphine
name: Langlade, Aimé
name: Gal, Dominique Le
name: Terre-Terrillon, Aouregan
name: Courtois, Olivier
name: Guichard, Benjamin
name: Arzul, Isabelle
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Chromista
Cercozoa
Mikrocytiidae
Mikrocytos
Mikrocytos donaxi

description: Mikrocytos donaxi n. sp.
Type-host: Donax trunculus Linnaeus, 1758 (Mollusca, Bivalvia, Heterodonta, Veneroida, Tellinoidea, Donacidae).
Type-locality: Atlantic coast of France: Audierne Bay (47.85°N, 4.35°W).
Type-material: Fixed tissues (foot and mantle, accession No. 11/089/06, 11/089/25 and 11/089/27) infected with Mikrocytos donaxi n. sp. have been deposited at the OIE Reference Laboratory for infection with Mikrocytos mackini: Pacific Biological Station, Aquatic Animal Health Section, 3190 Hammond Bay Road, Nanaimo, British Columbia V 9 T 6 N7, Canada.
Representative DNA sequences: Nucleotide sequences of partial 18S DNA region have been submitted in the GenBanc database under the accession numbers KY923804 – KY923807 as well as a nucleotide sequence of the ITS1-5.8S-ITS2 DNA region (accession number: KY923808).
ZooBank registration: To comply with the regulations set out in article 8.5 of the amended 2012 version of the International Code of Zoological Nomenclature (ICZN) [49], details of the new species have been submitted to ZooBanc. The Life Science Identifier (LSID) of the article is urn:lsid:zoobanc.org:pub: E1747954-CBDF-4F4A-BA22- E1C3CD1776BD. The LSID for the new name Mikrocytos donaxi is urn:lsid:zoobanc.org:act: 307DFFED-D663- 4ACA-A9AF-F98FC90B0896.
Etymology: The specific epithet refers to the genus of the host Donax trunculus.
Description
[Based on 20 specimens.] Oval to round parasites (Fig. 3) measuring 1.84 – 3.20 × 1.07 – 2.42 (2.52 ± 0.18 × 1.76 ± 0.13) μm with a nucleus of 0.68 – 1.38 × 0.59 – 1.09 (1.15 ± 0.08 × 0.85 ± 0.07) μm (Table 2). Uninucleate cell with eccentric nucleus variable in form (Fig. 8a). Intracellular or extracellular parasite of myocytes and vesicular cells of mantle, foot, adductor muscles, nerves (Fig. 3b, c) and also, in vesicular cells of digestive gland, gills and gonads. No mitochondria noted inside parasite cytoplasm. Parasite cells often surrounded by mitochondria and sometimes, observation of depression of parasite membrane (Fig. 8b). No plasmodial or spore stage noted. Only dense form observed with very granulous cytoplasm (Fig. 8a).
Remarks
Mikrocytos donaxi n. sp. presented the same morphological characteristics as M. veneroïdes n. sp. except for some particular traits. The nucleus of M. donaxi n. sp. seemed more frequent in eccentric position than in M. veneroïdes n. sp. Another difference in terms of size was also observed between these two species: M. donaxi n. sp. seemed smaller than M. veneroïdes n. sp. The close association with mitochondria was also noted for M. donaxi n. sp. as for M. veneroïdes n. sp. and for both parasites, in rare cases (observed in two parasite cells from Quiberon Bay and Audierne Bay), a mitochondrion appeared to be inside the cytoplasm of the microcell (Fig. 7c). M. donaxi n. sp. presented dense forms similar to those of M. veneroides n sp. but no clear forms were observed contrary to M. veneroïdes n. sp. The different uninucleate stages (quiescent, endosomal and vesicular cells) described for Mikrocytos spp. [5, 50] were not always observed in ultrastructure studies of M. donaxi n. sp.: in some samples, it was possible to distinguish some parasite cell types as the endosomal cells presenting a well-developed anastomosing endoplasmic reticulum (Fig. 8c).The non-observation of these different stages could be due to the darc aspect of the cytoplasm limiting ultrastructural observations of M. donaxi n. sp.
description: Published as part of Garcia, Céline, Haond, Christophe, Chollet, Bruno, Nerac, Mirella, Omnes, Emmanuelle, Joly, Jean-Pierre, Dubreuil, Christine, Serpin, Delphine, Langlade, Aimé, Gal, Dominique Le, Terre-Terrillon, Aouregan, Courtois, Olivier, Guichard, Benjamin & Arzul, Isabelle, 2018, Descriptions of Mikrocytos veneroïdes n. sp. and Mikrocytos donaxi n. sp. (Ascetosporea: Mikrocytida: Mikrocytiidae), detected during important mortality events of the wedge clam Donax trunculus Linnaeus (Veneroida: Donacidae), in France between 2008 and 2011, pp. 1-16 in Parasites & Vectors (119) (119) 11 (1) on pages 11-12, DOI: 10.1186/s13071-018-2692-0, http://zenodo.org/record/11074588