ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Accepted by B. Bentlage: 1 Jul. 2021; published: 11 Nov. 2021 429 Zootaxa 5067 (3): 429–438 https://www.mapress.com/j/zt/ Copyright © 2021 Magnolia Press Article https://doi.org/10.11646/zootaxa.5067.3.6 http://zoobank.org/urn:lsid:zoobank.org:pub:D8A6DE2B-EEE6-414E-A606-AF94E1A46EB0 First report of Ceratomyxa scorpaeni (Cnidaria: Myxozoa) from Scorpaena porcus in the Black Sea SEVİLAY OKKAY 1,2,5 , C. TOLGA GÜRKANLI 3,6 , YILMAZ ÇİFTÇİ 3,7 , VİOLETTA YURAKHNO 4,8 & AHMET ÖZER 1 * 1 Sinop University, Faculty of Fisheries and Aquatic Sciences, 57000, Sinop, Turkey 2 Kocaeli University, Faculty of Agriculture, 41285, Kocaeli, Turkey 3 Ordu University, Fatsa Faculty of Marine Sciences, 52400, Fatsa-Ordu, Turkey 4 A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, 2 Nakhimov av., 299011 Sevastopol, Crimea 5 � sevilayokkay@gmail.com; https://orcid.org/0000-0003-4440-3525 6 � cgurkanli44@gmail.com; https://orcid.org/0000-0001-8378-7109 7 � yciftci@gmail.com; https://orcid.org/0000-0003-4553-990X 8 � viola_taurica@mail.ru; https://orcid.org/0000-0002-0571-6716 * Corresponding author. � aozer@sinop.edu.tr; https://orcid.org/0000-0002-2890-6766 Abstract Members of the class Myxosporea Bütschli, 1881 have a cosmopolitan distribution in a wide variety of fish species worldwide. In the present study, the black scorpionfish Scorpaena porcus collected from the Sinop coasts of the Black Sea was investigated for myxosporean parasites using both conventional and molecular methods in the period between September 2015 and August 2019. Using morphological and morphometric data, the myxosporean parasite Ceratomyxa scorpaeni Garbouj, Rangel, Castro, Hmissi, Santos, Bahri, 2016 was identified in the gall bladder of host fish. Molecular analysis of the 18S rDNA gene confirmed the identity of this parasite as C. scorpaeni. This is the first report of its occurrence in the Black Sea. Key words: Myxozoa, Ceratomyxa scorpaeni, Scorpaena porcus, Black Sea Introduction Myxosporeans are microscopic parasites of fish, amphibians, rarely reptiles, birds, mammals and worms such as poly- chaete and oligochaete (Fiala et al. 2015). Among myxosporeans, the genus Ceratomyxa Thelohan, 1892 has a worldwide distribution with more than 270 species in a wide variety of fish species, infecting mainly the gall-bladder but with some species belonging to this genus rarely infecting other organs, such as the urinary bladder, kidneys, gonads, internal surface of the digestive system and so on (Eiras 2006; Günter & Adlard, 2010; Eiras et al. 2018). Thus far, based on spore mor- phology, only 5 species have been reported from the gall bladder of several fish species inhabiting Turkish waters of the Black Sea and those are Ceratomyxa spp. from Dicentrarchus labrax (Özer & Öztürk 2011), Ceratomyxa beloneae from Belone belone (Özer & Yurakhno, 2013), Ceratomyxa merlangi from Merlangius merlangus (Özer et al. 2017), Cerato- myxa sp. from Scophthalmus maeoticus (Yurakhno et al. 2017) and Ceratomyxa elegans from Scorpaena porcus (Okkay et al. 2018). The black scorpionfish Scorpaena porcus is a widely distributed fish species in the Black Sea, the Eastern Atlantic Ocean and the Mediterranean Sea and, thus far, five species of myxozoans, Ceratomyxa arcuata, C. scorpaeni, C. elegans, C. verudaensis and Ceratomyxa sp. have been reported from this host fish in the Mediterranean Sea and the Black Sea (Yurakhno 1993,1997; Lom & Dykova 2006; Hmissi 2014; Fiala et al. 2015; Garbouj et al. 2016). Based on the current literature following the inclusion of molecular characters in myxozoan taxonomy, Heiniger & Adland (2013) indicated that marine Ceratomyxa are generally highly host specific and typically restricted to a single host species. Gunter & Adlard (2010) have provided a comprehensive up to date revision for this genus to include recently published morphological descriptions for the members of the genus. Despite several morphology-based revisions, it is still difficult to differentiate similar Ceratomyxa species. A total of 147 DNA sequences are currently available for Ceratomyxa spe- cies in the GenBank database despite double the number of identified species based on spore morphology in the current