On the validity and distribution of Myxobolus curemae Vieira, Agostinho, Negrelli, Silva, Azevedo and Abdallah, 2022 (Myxozoa: Bivalvulida) from a new record on the coast of southeastern Brazil.

Myxobolus spp. are parasites of wide diversity and distribution in fish, both in the natural environment and in freshwater or marine farming systems around the world and are sometimes associated with severe disease in their hosts (Schmahl et al. 1989; Lom and Dyková, 1995; Eiras et al. 2021). The white mullet Mugil curema Valenciennes, 1836 is a pelagic fish of the Mugilidae family widely distributed in the Atlantic Ocean (Froese & Pauly 2022). Recently, Myxobolus curemae Vieira, Agostinho, Negrelli, Silva, Azevedo and Abdallah, 2022 was described from white mullets Mugil curema Valenciennes, 1836 in Brazil (Vieira et al. 2022). In the current work, Myxobolus sp. was identified with the same biological and morphological characteristic features of M. curemae from white mullets from the Jacarepaguá Lagoon Complex in the State of Rio de Janeiro, Brazil, in addition to being 100% identical for a genic region of the nuclear small subunit ribosomal DNA. However, this Myxobolus sp. was also similar to Myxobolus hani Faye, Kpatcha, Diebakate, Fall and Toguebaye, 1999, which was described from white mullets in Senegal, Africa, without molecular identification (Faye et al. 1999). Therefore, this current work makes observations on these Myxobolus spp. which are morphologically and biologically similar, and that could establish M. curemae as a junior synonymy of M. hani.

First report of Myxobolus episquamalis Egusa, Maeno & Sorimachi, 1990 (Myxozoa: Bivalvulida) in Lebranche mullet Mugil liza Valenciennes, 1836 (Teleostei: Mugiliformes) from Neotropical region.

In the current study, Myxobolus episquamalis Egusa, Maeno & Sorimachi, 1990 (Myxozoa: Bivalvulida) is reported from the Lebranche mullet Mugil liza Valenciennes, 1836 in the estuarine region of the Maricá Lagoon, State of the Rio de Janeiro, southeastern Brazil. To date, this myxozoan species was reported in mullets from Asia, Africa, Europe, and Oceania. The characteristics of M. episquamalis previously reported are similar to the findings of the present study. DNA sequences of the nuclear small subunit ribosomal DNA (SSU rDNA) had 99.7-100% similarity with the sequences of M. episquamalis from North Africa and Asia. Therefore, strong morphological and molecular similarities ensure the identification of M. episquamalis in the current study. Finally, this finding records a new host and locality, revealing the worldwide distribution of this myxozoan species.