Skin nodules associated with parasitism with Henneguya sp. (Cnidaria: Myxosporea) in the neotropical fish Cyphocharax modestus

• Published in: Microbial pathogenesis 2019-03, Vol.128, p.294-300
• Main Authors: Mirandola Dias Vieira, Diego Henrique, Abdallah, Vanessa Doro, José da Silva, Reinaldo, Kozlowiski de Azevedo, Rodney
• Format: Article
• Language: English
• Subjects: Characiformes; Histopathology; Peixe river; Ultrastructural
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/j.micpath.2019.01.027

A new myxozoan species, Henneguya sp., is described based on material from skin of Cyphocharax modestus. Mature myxospores are were elongate and ellipsoidal, measuring 21.4 ± 1.2 (19.4–23.2) μm in total length, 5.1 ± 0.3 (4.5–5.8) μm in width, 11.9 ± 0.5 (10.9–12.7) μm in body length and 9.6 ± 0.7 (8.4–10.5) μm in length of the caudal process. The polar capsules were elongated and had unequal sizes, with length of 5.1 ± 0.4 (4.5–6.0) μm and 5.6 ± 0.4 (4.9–6.3) μm for smaller and larger respectively and width of 1.8 ± 0.2 (1.4–2.0) μm. The larger polar capsule had 8 turns in polar filament while the smaller polar capsule had 5 turns in polar filament. The macroscopic analysis revealed the presence of large nodules, which were located before and after the dorsal fin of the hosts. The histopathological analysis showed the development of nodules filled with plasmodia, surrounded by loose connective tissue, developed in the dermis of the skin. Many cysts containing countless spores, as well as free spores, were located in the dermis and hypodermis of the hosts, causing the disorganization of the connective tissue that is responsible for the support. This is the first record of a Henneguya species in C. modestus. •The macroscopic analysis of Cyphocharax modestus revealed the presence of large nodules caused by a myxozoan species.•Nodules filled with plasmodia, surrounded by loose connective tissue, developed in the dermis of the skin were observed.•This research contributes to the knowledge about the biodiversity of myxozoans in Brazil.•We suggest that the new species, after determination by molecular analysis, be named as Henneguya parvacauda.