Description of Myxobolus hoabinhensis n. sp. (Myxosporea: Myxobolidae), infecting the trunk muscles of goldfish Carassius auratus (Linnaeus, 1758) (Cypriniformes: Cyprinidae) in northern Vietnam

• Published in: Parasitology research (1987) 2022-09, Vol.121 (9), p.2495-2502
• Main Authors: Chinh, Nguyen Ngoc, Tham, Nguyen Thi, Yurakhno, Violetta M., Doanh, Pham Ngoc, Whipps, Christopher M., Shirakashi, Sho
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Biomedicine; Carassius auratus; Cyprinidae; Cypriniformes; Fish Parasitology - Original Paper; Immunology; Medical Microbiology; Microbiology; Muscles; Myxobolidae; Myxobolus; Myxosporea; Myxospores; Nucleotide sequence; Phylogenetics; Phylogeny; Physical characteristics; Spores
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-022-07586-5

During a survey of myxosporean parasites of freshwater fishes in northern Vietnam, myxospores resembling those of the genus Myxobolus (Myxosporea: Myxobolidae) were found in the trunk muscle of 6 out of 35 specimens (17.14%) of wild goldfish Carassius auratus (Cypriniformes: Cyprinidae). The mature spores were 12.0 ± 0.4 (11.4 − 12.6) µm long, 8.5 ± 0.2 (7.9 − 9.0) µm wide and 6.1 ± 0.2 (5.8 − 6.3) µm thick, containing two pyriform-shaped polar capsules unequal in size. The larger polar capsule was 7.6 ± 0.3 (7.1 − 8.4) µm long and 3.5 ± 0.1 (3.3 − 3.8) µm wide, and the smaller polar capsule was 6.2 ± 0.3 (5.5 − 6.7) µm long and 2.9 ± 0.2 (2.6 − 3.4) µm wide. Each polar capsule contained a polar filament with 3–5 coils. A phylogenetic analysis based on the small subunit rDNA (SSU rDNA) sequence revealed that this Myxobolus species forms a distinct branch in the phylogenetic tree sister to Myxobolus artus and Myxobolus cyprini , with DNA sequence similarity at 97.6% to M. artus and 97.5% to M. cyprini . A combination of the morphological characteristics and molecular data suggest that this is an undescribed species, and we propose the name Myxobolus hoabinhensis n. sp.