Document Type : Short Communication

Author

Department of Fisheries Health, Central Fisheries Research Institute, Trabzon, Turkey

Abstract

Scuticociliates are dangerous parasitic pathogens causing systemic tissue destruction and high mortality in marine fish worldwide. In this study, the first identification of Uronema marinum (Ciliophora, Scuticociliatida) from cultured turbot (Psetta maxima) larvae using mitochondrial cytochrome c oxidase 1 (cox1) gene sequence as well as species-specific primers was reported. The mean prevalence values of infected fish were calculated, and partial sequencing obtained from the mitochondrial cox1 gene region was also compared with isolates registered in the Genbank database. The sequence comparison showed 93.00% identity to U. marinum, and the parasite has also been deposited in the GenBank database. This study is the first case of U. marinum infection in Turkish marine aquaculture, contributing to the systematics and molecular epidemiology of scuticociliate in Turkey.

Keywords

  1. Barber I. Parasites, behaviour and welfare in fish. Appl Anim Behav Sci 2007; 104(3-4): 251-264.
  2. Turgay E, Steinum TM, Gül AE. et al. An outbreak of scuticociliatosis in cultured common dentex (Dentex dentex) in Turkey. Bull Eur Assoc Fish Pathol 2015; 35(3): 104-111.
  3. Bradbury PC. Pathogenic ciliates. In: Hausmann K, Bradbury PC (Eds). Ciliates: cells as organisms. Deer-field Beach, USA; Gustav Fischer Verlag 1996 463-477.
  4. Iglesias R, Paramá A, Alvarez MF, et al. Philasterides dicentrarchi (Ciliophora, Scuticociliatida) as the causative agent of scuticociliatosis in farmed turbot Scophthalmus maximus in Galicia (NW Spain). Dis Aquat Organ 2001; 46(1): 47-55.
  5. Sterud E, Hansen MK, Mo TA. Systemic infection with Uronema like ciliates in farmed turbot, Scophthalmus maximus (L.). J Fish Dis 2000; 23(1): 33-37.
  6. Du G, Qu L, Shang K, et al. Ciliate Uronema marinum is the causative agent of scuticociliatosis in farm raised turbot Scophthalmus maximus. J Oceanol Limnol 2019; 37: 1726-1735.
  7. Sahin T. Larval rearing of the Black Sea turbot, Scophthalmus maximus (Linnaeus, 1758), under laboratory conditions. Turk J Zool 2001; 25: 447-452.
  8. Aksungur N, Aksungur M, Akbulut B, et al. Effects of stocking density on growth performance, survival and
    food conversion ratio of turbot (Psetta maxima) in the net cages on the southeastern coast of the Black Sea. Turkish J Fish Aquat Sci 2007; 7: 147-152.
  9. Kayis S, Yandi I, Altinok I, et al. Treatment by vinegar of Philasterides dicentrarchi (Ciliophora: Scuticociliatida) infestation in cultured juvenile turbot (Psetta maxima). Isr J Aquac 2011; 63: 627-631.
  10. Jung SJ, Im, EY, Strüder-Kypke MC, et.al. Small subunit ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1 gene sequences of 21 strains of the parasitic scuticociliate Miamiensis avidus (Ciliophora, Scuticociliatia). Parasitol Res 2011; 108(5): 1153-1161.
  11. Whang I, Kang HS, Lee J. Identification of scuticociliates (Pseudocohnilembus persalinus, P. longisetus, Uronema marinum and Miamiensis avidus) based on the cox1 sequence. Parasitol Int 2013; 62(1): 7-13.
  12. Foissner W. Basic light and scanning electron microscopic methods for taxonomic studies of ciliated protozoa. Eur J Protistol 1991; 27(4): 313-330.
  13. Er A, Kayış Ş. Intensity and prevalence of some crustacean fish parasites in Turkey and their molecular identification. Turk J Zool 2015; 39(6): 1142-1150.
  14. Kumar S, Stecher G, Li M, et al. MEGA X: Molecular evolutionary genetics analysis across computing platforms. Mol Biol Evol 2018; 35(6): 1547-1549.
  15. Tamura K, Nei M. Estimation of the number of nucleotide substitutions in the control region of mitochondrial DNA in humans and chimpanzees. Mol Biol Evol 1993; 10(3): 512-526.
  16. Guindon S, Gascuel O. A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Syst Biol 2003; 52(5): 696-704.
  17. Pan X, Huang J, Fan X, et al. Morphology and phylogeny of four marine scuticociliates (Protista, ciliophora), with descriptions of two new species: Pleuronema elegans spec. nov. and Uronema orientalis spec. nov. Acta Protozool 2015; 54: 31-43.
  18. Song W, Wilbert N. Reinvestigations of three “well-known” marine scuticociliates: Uronemella filificum (Kahl, 1931) nov. gen., nov. comb., Pseudocohnilembus hargisi Evans & Thomp­son, 1964 and Cyclidium citrullus Cohn 1865, with description of the new genus Uronemella (Protozoa, Ciliophora, Scutico­ciliatida). Zool Anz 2002; 241(4): 317-331.
  19. Song W. Morphological and taxonomical studies on some marine scuticociliates from China Sea, with description of two new species, Philasterides armatalis sp. n. and Cyclidium varibonneti sp. n. (Protozoa: Ciliophora: Scuticociliatida). Acta Protozool 2000; 39: 295-322.
  20. Folmer O, Black M, Hoeh W, et al. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Mol Mar Biol Biotechnol 1994; 3(5):294-299.