FIRST MOLECULAR EVIDENCE OF CERATOMYXA EPINEPHELA (MYXOZOA: CERATOMYXIDAE) AND ITS GENETIC VARIATION FROM DIFFERENT HOST SPECIES

Ceratomyxa epinephela Wu, Wu et Hua, 1993 is originally found to infect the gallbladder of Epinephelus akaara Temminck & Schlegel, 1842 from South China Sea, and no molecular data have been provided up to date. In the present study, we detected this species infecting the gallbladder of E. awoara Temminck & Schlegel, 1842 and E. bruneus Bloch, 1793 from East China Sea. For the first time, we offered the SSU rDNA and ITS1 rDNA information for this species and redescribed such species based on the combination of morphological and molecular data. Mature spores of C. epinephela were (4.8±0.5) μm (3.6—5.6 μm) in length and (31.8±4.8) μm (23.3—37.5 μm) in thickness. Myxospores valves were smooth and almost equal, which were joined by a prominent suture. Polar capsules measured (2.9±0.2) μm (2.4—3.7 μm) in length and (2.6±0.2) μm (2.2—3.1 μm) in width. Posterior angle was slightly concave to flat, measured (175.9±3.7)° (165.5°—179.7°). Phylogenetic analysis based on SSU rDNA revealed that C. epinephela had the close relationship with C. nolani Gunter & Adlard, 2009, C. cutmorei Gunter & Adlard, 2009, and C. yokoyamai Gunter & Adlard, 2009, all of whose host were epinephelids. It also implied that the close host affinity might have close phylogenetic relationships of their myxosporean parasites. The sequences analysis based on SSU rDNA and ITS1 rDNA revealed that the four isolates of C. epinephela had already formed different populations, while the species did not form a specialized genetic characteristic among its different host species.