DAO prepress abstract  -  DOI: https://doi.org/10.3354/dao03192

Morphology and molecular phylogeny of Ortholinea mullusi sp. nov. (Myxozoa) in Mullus barbatus from the Black Sea

C. T. Gürkanlı, S. Okkay, Y. Çiftçi, V. Yurakhno, A. Özer*

*Email: aozer@sinop.edu.tr

ABSTRACT: Myxosporeans of the genus Ortholinea have a worldwide distribution and infect organs and tissues of exclusively marine fishes. Here we describe the morphological and molecular characteristics of Ortholinea mullusi sp. nov. parasitizing the urinary bladder and kidney tubules of the red mullet Mullus barbatus collected from the coastal zone near Sinop in the Black Sea, Turkey. Polysporic plasmodia with immature spores were either elongate, 37.0 ± 4.5 (30–50) μm long and 45.0 ± 3.8 (40–55) μm wide, or round up to 100.0 μm in diameter. Mature, free spores spherical in the frontal view measured 9.3 ± 0.2 (9.0−9.7) µm in length, 8.7 ± 0.3 (8.2−9.3) μm in width and 7.7 ± 0.1 (7.5−7.9) µm in thickness. Polar capsules two, equal, measured 3.1 ± 0.1 (3.0–3.2) µm long by 2.5 ± 0.1 (2.4–2.6) µm wide, and the tips of the polar capsules open towards the sutural line. The prevalence of infection by O. mullusi sp. nov. was 24.5%. Phylogenetic analysis based on nuclear small subunit ribosomal DNA (SSU rDNA) clearly suggested O. mullusi to be a new species, clustered within a lineage comprising of O. labracis and O auratae. Pairwise nucleotide similarities and DNA distance values between O. mullusi sp. nov. and sister Ortholinea species also supported this suggestion.