Ultrastructural, ssrDNA sequencing of Myxobolus prochilodus and Myxobolus porofilus and details of the interaction with the host Prochilodus lineatus

Abstract

Myxobolus prochilodus and Myxobolus porofilus are parasites of Prochilodus lineatus, an economically important South American fish found in La Plata and Paraiba do Sul river basins. This study focusing on parasite-host interaction provides an ultrastructural and phylogenetic analysis, the latter based on ssrDNA sequencing of these parasites respectively infecting the gill filaments and fins of P. lineatus taken from the Mogi Guaçu River, São Paulo, Brazil. A total of 13 adult specimens were examined in this study. The prevalence of infection was 7.69 % for M. prochilodus and 15.38 % for M. porofilus. Phylogenetic analysis showed M. prochilodus and M. porofilus clustered in a subclade composed of parasites of the Prochilodontidae family. In M. prochilodus infecting gill filaments, where cellular degeneration in the epithelium was observed, the plasmodia were surrounded by a capsule composed of layers of fibrocyte-like cells, with cellular projections joined to the projections of other fibrocyte-like cells by desmosomes, and more externally typical fibroblast layers. Some granular leukocytes were seen interspersed among these layers. In M. porofilus infecting the fins, the capsule of connective tissue was represented only by loosely arranged collagen fibers, and no granular leucocytes were observed. Finally, several unusual vacuoles with filamentous content and some characteristics usually described as degenerative alterations, as myelin figure, were noted in plasmodia and pansporoblasts of both myxosporean species. The possible influence of inflammatory response and xenobiotics was considered to be the explanation for the alterations observed in Myxobolus species and its host.

Effects of sublethal and realistic concentrations of the commercial herbicide atrazine in Pacu (Piaractus mesopotamicus): Long-term exposure and recovery assays

“…Kidneys from all pacu fingerlings sampled for histopathological analysis were infected by Myxozoa. This is a highly diverse taxon of endoparasites that are very often found in freshwater and saltwater fish and also in fish kept in aquaculture, which can cause damage to the tissue parasitized [45]. Myxozoa infection in pacu seems to cause several changes in CTs, including necrosis, but no effects in nephron tubules.…”

Henneguya correai n. sp. (Cnidaria, Myxozoa) Parasitizing the Fins of the Amazonian Fish Semaprochilodus insignis

“…The Myxobolus species M. iarakiensis, M. porofilus Adriano, Arana, Ceccarelli and Cordeiro, 2002, M. maiai, M. curimatae Zatti, Naldoni, Silva, Maia and Adriano, 2015 and M. prochilodus Azevedo, Vieira, Vieira, Silva, Matos and Abdallah, 2014 comprise a lineage in clade B, while the two Henneguya parasites Henneguya correai n. sp. and H. tietensis cluster together in clade A [14,34,45,46]. These data reveal that despite overall polyphyly of myxobolid parasites of prochilodontids, there exist monophyletic sub-groups of the Henneguya and Myxobolus species.…”

“…This taxon could be distinguished from all other described species on the basis of morphological and morphometric characters and ssrDNA sequence. Ultrastructural analysis revealed pinocytic channels at the host-parasite interface (Figure 3), which are common among Myxobolidae and considered to be related to nutrition and sporogonic development [10,11,19,28,[32][33][34][35].…”