Novel Amazonian Ceratomyxa species (Cnidaria: Myxozoa) with amoeboid plasmodial motility

Author(s)

Muller, Maria I. ; Atkinson, Stephen D. ; Bartholomew, Jerri L. ; Adriano, Edson A.

• Document type: Journal article
• Source: Microbial Pathogenesis; v. 199, p. 8-pg., 2025-01-02.

Abstract

Myxosporeans are a diverse group of cnidarian endoparasites of aquatic animals, with more than 2600 described species. The genus Ceratomyxa includes some 270 species that are mostly coelozoic and infect the gall bladders of mainly marine fish. During our survey in Tapajo<acute accent>s River in the Brazilian Amazon, two Ceratomyxa species were discovered in the gallbladders of the anostomid fishes Schyzodon fasciatus and Schyzodon vittatus. Based on myxospore morphology and sequencing of small subunit ribosomal DNA, we propose that these are novel Ceratomyxa species. Ceratomyxa deformis n. sp. from S. fasciatus and Ceratomyxa anomala n. sp. from S. vittatus are similar in morphology, with mature myxospores slightly arcuate with rounded ends. Plasmodia are elongated, and can move by expanding and contracting the cytoplasm. This amoeboid-like motility is heretofore unreported in freshwater South American Ceratomyxa species. Ultrastructural analyses showed the plasmodial organization of both species comprised a cytoplasmic region harboring organelles and sporogonic stages and an internal large vacuole. Phylogenetic analysis corroborates monophyletic grouping of freshwater Ceratomyxa species from South America. Ceratomyxa deformis n. sp. and C. anomala n. sp., which are the first Ceratomyxa species described in anostomid fishes, grouped as sister taxa to C. gracillima and C. mandi, which infect bile in pimelodid fishes from the Amazon region. (AU)

• FAPESP's process: 17/16546-3 - Systematic and distribution of myxosporeans of Potamotrygonidae (Elasmobranchii, Myliobatiformes) in Amazon, Platina and Parnaíba river basins.
• Grantee: Maria Isabel Muller Formico
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 21/06692-8 - Transcriptomic analysis of genes related to biomineralization and motility in myxozoan parasites of fish
• Grantee: Maria Isabel Muller Formico
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 18/24980-8 - Myxozoa - cnidarians adapted to parasitismo: integrating different tools to investigate diversity, evolutionary history, development, and host-parasite interactions
• Grantee: Edson Aparecido Adriano
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants