Caracterização morfomolecular de myxozoários em Astyanax Mexicanus de Fillipi, 1853 (Characiformes: Characidae) do Rio Flexal, Amapá - Brasil.

Abstract

The Amazon stands out for its high biodiversity index, covering an area of over seven million square kilometers and present in nine countries. This biome is home to the largest river on the planet, the Amazon River, which is the result of a vast network of rivers and is home to thousands of species of fish ranging from basal to endemic species. The state of Amapá is located in the eastern Amazon and is part of this hydrographic network, with a privileged location; its coast is divided between oceanic and estuarine environments, naturally increasing its vocation for extractive fishing. The aquatic habitat has physical characteristics suitable for the development of parasites from various groups, and fish are the vertebrate hosts with the highest prevalence rate of parasitic infections, including Myxozoa, which are microscopic Cnidarian endoparasites, organized in multicellular spores, with or without caudal extension and filamentous polar capsules, potentially capable of causing serious outbreaks and economic losses. In this context, the objective of this work was to describe, under morphological and phylogenetic aspects, the occurrence of Myxozoa in Astyanax mexicanus, from the Flexal River, near the community of Tessalônica, Macapá, Amapá, in the Brazilian Amazon. A total of 62 specimens were captured between December 2022 and February 2024 and transported alive to the Laboratory of Morphophysiology and Animal Health at the State University of Amapá, where they were anesthetized and desensitized for analysis of all organs. During the morphological analyses, the presence of three taxa of the class Myxozoa was observed: Myxobolus, Henneguya and Ceratomyxa. The morphological data together with the molecular and phylogenetic analyses supported the description of a new species of freshwater Ceratomyxa, present in the gallbladder supernatant of Astyanax mexicanus.