Description of Cystodiscus elachistocleis sp. nov. (Cnidaria: Myxosporea) parasitizing the gallbladder of Elachistocleis cesarii from Brazil, based on morphological and molecular analyses

Diego Henrique Mirandola Dias Vieira,Lucia Helena O´Dwyer,Enzo Emmerich,Letícia Pereira Úngari,Edna Paulino De Alcantara,André Luiz Quagliatto Santos,Reinaldo José Da Silva

doi:10.5852/ejt.2021.775.1549

Diego Henrique Mirandola Dias Vieira, Lucia Helena O´Dwyer + Show 5 more

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https://doi.org/10.5852/ejt.2021.775.1549

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Abstract

Numerous pseudoplasmodia containing myxospores belonging to the genus Cystodiscus were found in the gallbladder of Elachistocleis cesarii from Mato Grosso State, Brazil. Herein, we describe Cystodiscus elachistocleis sp. nov., using morphological and small subunit ribosomal DNA sequences. The mature myxospores were ellipsoid to ovoid, measuring in average 10.6 (9.8–11.2) μm in length and 6.2 (5.6–6.6) μm in width. Polar capsules were pyriform and equal in size measuring in average 3.6 (2.8–4.3) μm in length and 2.6 (2.2–3.1) μm in width. Polar filaments had 2–4 coils. The myxospores had 3–5 transverse ridges. The phylogenetic analysis showed Cystodiscus elachistocleis sp. nov. as a sister species of Cystodiscus cf. immersus 1, in a subclade formed by species that parasitize the amphibians gallbladder. This is the first species of Cystodiscus described parasitizing a species of Elachistocleis and the third species of Cystodiscus described in Brazil.

Highlights

Myxozoans are cnidarians parasites with a complex life cycle (Lom & Dyková 2006). Lutz (1889) proposed the genus Cystodiscus Lutz, 1889 to accommodate Cystodiscus immersus Lutz, 1889 based on a large disc-like appearance found in the amphibious gallbladder
Considering the myxospore morphology, the morphometric data, and SSU rDNA gene partial sequence obtained in the present study, we described C. elachistocleis sp. nov
This finding contributes to our knowledge of the biodiversity of Cystodiscus in amphibians from Brazil

Summary

Introduction

Myxozoans are cnidarians parasites with a complex life cycle (Lom & Dyková 2006). Lutz (1889) proposed the genus Cystodiscus Lutz, 1889 to accommodate Cystodiscus immersus Lutz, 1889 based on a large disc-like appearance found in the amphibious gallbladder. The genus was abandoned and classified as a synonym of Myxidium Bütschli, 1882; Hartigan et al (2012), performing phylogenetic molecular analyses, reerected the genus Cystodiscus as a monophyletic group instead of the polyphyletic nature of Myxidium. They have a global distribution and are endoparasites of a great diversity of amphibian hosts (Hartigan et al 2012a, 2012b, 2016). Due to its pathogenic potential, the parasite can have an important ecological impact on the conservation of amphibians (Hartigan et al 2012c)

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