First record of a Myxobolus species in the kidney of sharpsnout seabream from the Black Sea, Turkey

Myxobolus Bütschli, 1882 is the most species-rich myxozoan genus, but few of its species have been described from sparid fishes. The aim of the present study was to characterise, using morphological and molecular methods, a Myxobolus species detected in the kidney of the sharpsnout seabream Diplodus puntazzo caught on the Black Sea coast of Turkey. Between February and March 2026, nine fish were examined for myxosporean infection, and Myxobolus spores were detected in the kidney with a prevalence of 88.9% (8/9). Mature spores were ellipsoidal and lacked caudal appendages, measuring 10.1 ± 0.6 (8.9–11.2) µm in length, 5.7 ± 0.6 (4.5–6.7) µm in width and 5.1 ± 0.6 (4.5–6.6) µm in thickness. The two equal and pyriform polar capsules measured 3.7 ± 0.2 (3.0–4.0) µm in length and 2.0 ± 0.1 (1.7–2.2) µm in width. Molecular analyses based on partial small subunit ribosomal DNA (SSU rDNA) sequence data showed the highest similarity to Myxobolus branchiostegi, followed by M. iwagiensis and M. tai. In the phylogenetic analyses it was placed within a strongly supported clade together with these three species, separate from other marine myxobolid species. The morphological and molecular findings place the parasite within the genus Myxobolus. However, the sequence obtained here covers only part of the SSU rDNA gene and is therefore insufficient for species-level identification. This study provides the first genetic data for a Myxobolus species from D. puntazzo and a new record of the genus from this host in the Black Sea.