FN Archimer Export Format PT J TI 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 BT AF GARCIA, Celine HAOND, Christophe CHOLLET, Bruno NERAC, Mirella OMNES, Emmanuelle JOLY, Jean-Pierre DUBREUIL, Christine SERPIN, Delphine LANGLADE, Aime LE GAL, Dominique TERRE-TERRILLON, Aouregan COURTOIS, Olivier GUICHARD, Benjamin ARZUL, Isabelle AS 1:1;2:1;3:1;4:1;5:1;6:1;7:1;8:1;9:2;10:3;11:3;12:4;13:1;14:1; FF 1:PDG-RBE-SGMM-LGPMM;2:;3:PDG-RBE-SGMM-LGPMM;4:PDG-RBE-SGMM-LGPMM;5:PDG-REM-EEP-LEP;6:PDG-RBE-SGMM-LGPMM;7:;8:PDG-RBE-SGMM-LGPMM;9:PDG-ODE-LITTORAL-LERMPL;10:PDG-ODE-LITTORAL-LERBO;11:PDG-ODE-LITTORAL-LERBO;12:;13:;14:PDG-RBE-SGMM-LGPMM; C1 IFREMER, RBE SG2M LGPMM, Stn La Tremblade, Ave Mus Loup, F-17390 La Tremblade, France. IFREMER, ODE LITTORAL LERMPL, Stn Trinite Mer, 12 Rue Resistants, F-56470 La Trinite Sur Mer, France. IFREMER, ODE LITTORAL LERBO, Stn Concarneau, Pl Croix, F-29185 Concarneau, France. IFREMER, ODE LITTORAL LERPC, Stn La Tremblade, Ave Mus Loup, F-17390 La Tremblade, France. C2 IFREMER, FRANCE IFREMER, FRANCE IFREMER, FRANCE IFREMER, FRANCE SI LA TREMBLADE BREST LA TRINITE CONCARNEAU SE PDG-RBE-SGMM-LGPMM PDG-REM-EEP-LEP PDG-ODE-LITTORAL-LERMPL PDG-ODE-LITTORAL-LERBO IN WOS Ifremer jusqu'en 2018 DOAJ IF 3.031 TC 12 UR https://archimer.ifremer.fr/doc/00428/53989/55149.pdf https://archimer.ifremer.fr/doc/00428/53989/55176.pdf https://archimer.ifremer.fr/doc/00428/53989/55177.pdf LA English DT Article DE ;Mikrocytos veneroides n. sp.;Mikrocytos donaxi n. sp.;Donax trunculus;Mortality;Microcell parasite AB Background: Microcell parasites are small intracellular protozoans mostly detected in molluscs and can be associated with mortalities. In 2010 and 2011, strong increases in mortality events were reported in different wild beds of the wedge clam Donax trunculus Linnaeus, along the Atlantic coast of France and the presence of potential pathogens, including microcells, was investigated. Methods: Clams collected in different beds showing mortality were examined by histology. Based on histological observations, confirmatory analyses were carried out, including transmission electron microscopy (TEM) and molecular characterization. Results: Histological analyses revealed the presence of small protozoans similar to microcell parasites in different tissues of Donax trunculus , particularly in muscular and connective tissues. TEM examination confirmed the intracellular localization of the protozoans. Moreover, the lack of haplosporosomes and mitochondria suggested that the observed parasites belong to the genus Mikrocytos Farley, Wolf & Elston,  1988. Mikrocytos genus-specific PCR and in situ hybridization results supported the microscopic observations. Sequence fragments of the 18S rRNA gene shared 75–83% identity with the different Mikrocytos spp.  described previously, including Mikrocytos mackini Farley, Wolf & Elston, 1988 and M. boweri Abbott, Meyer, Lowe, Kim & Johnson, 2014. Phylogenetic analyses confirmed that the microcell parasites observed in Donax trunculus in France belong to the genus Mikrocytos and suggest the existence of two distinct species. Conclusions: Based on morphological, ultrastructural, molecular data and host information, the two microcell parasites detected in Donax trunculus belong to the genus Mikrocytos and are distinct from previously described membersofthisgenus.This  is the first report of Mikrocytos spp. found in France and infecting the clam Donax trunculus. Mikrocytos veneroïdes n. sp. was detected in different wild beds and Mikrocytos donaxi n. sp. was detected only in Audierne Bay. PY 2018 PD MAR SO Parasites & Vectors SN 1756-3305 PU Biomed Central Ltd VL 11 IS 1 UT 000427131000002 DI 10.1186/s13071-018-2692-0 ID 53989 ER EF