Myxobolus adrianoi Mathews & Madrid & Mertins & Rigoni & Morandini 2020, sp. nov
Creators: name: Mathews, Patrick D.
name: Madrid, Rafael R. M.
name: Mertins, Omar
name: Rigoni, Vera L. S.
name: Morandini, André C.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Myxozoa
Myxosporea
Bivalvulida
Myxobolidae
Myxobolus
Myxobolus adrianoi

description: Myxobolus adrianoi sp. nov.
urn:lsid:zoobank.org:act: 9FF87134-46B5-47AD-98FE-B97E6F913645
Figs 1–4
Etymology
The specific name, adrianoi, is in homage to Dr. Edson Adriano, Professor at Federal University of São Paulo, Brazil, who has been contributing to improving our knowledge on the diversity of South American Myxosporea.
Material examined
Syntypes
BRAZIL • 10+ myxospores; Amazonas State, Lábrea Municipality; 7°15′32″ S, 64°47′52″ W; air-dried slide stained with Giemsa; MZUSP 8469.
Type host
Corydoras schwartzi Rössel, 1963 (Siluriformes: Callichthyidae).
Site of infection
Serosa layer of intestine.
Prevalence
From 30 examined fish, five were infected (16.6%).
Description
Mature myxospores ovoid in body shape in frontal view, showing two aubergine-shaped, elongate symmetrical polar capsules occupying more than half length of spore. Total myxospore length 22.4 ± 0.3 μm and width 16.3 ± 0.1 μm. Two polar capsules, 14.3 ± 0.2 μm in length and 6.5 ±0.1 μm in width (Figs 2 A–D, 3).Fig. 2.Light photomicrograph of mature myxospores of
Myxobolus adrianoi sp. nov., parasite of the intestine ofCorydoras schwartziRössel, 1963.A. Wet-mount mature myxospores (white arrows).B–C. Frontal view of mature myxospores stained in May-Grünwald-Giemsa, showing two equal polar aubergine-like capsules, occupying more than half the length of the myxospore.D. Mature myxospore stained, in frontal view, with the polar filament extruded (black arrow).
Ultrastructural analysis showed myxospores in various stages of development. In young developmental myxospore stage, the polar filament could still be observed out of the polar capsules and valvogenic cells were readily recognized by valve-forming materials (Fig. 4A). In myxospores at a more advanced developmental stage, a polar filament inside the polar capsule and binucleated sporoplasms containing a moderate number of sporoplasmosomes were observed (Fig. 4 B–C). Transverse sections of a polar capsule provided evidence of a polar filament with five coils (Fig. 4 B–C). Sections of immature myxospores show the valvogenic cells abutting each other to form a sutural ridge, and frequently the two cells were separated by a thin layer of homogenous material (Fig. 4D). Almost mature myxospores showed sutural lines, valve-forming material, valves, two nuclei and sporoplasmosomes at sporoplasms (Fig. 4 E–F). The outer surface of the myxospore valves was smooth, with no evidence of formation of ridges in the valves (Fig. 4 E–F).
description: Published as part of Mathews, Patrick D., Madrid, Rafael R. M., Mertins, Omar, Rigoni, Vera L. S. & Morandini, André C., 2020, A new Myxobolus (Cnidaria: Myxosporea) infecting the ornamental catfish Corydoras schwartzi from the Purus River in Brazil, pp. 1-14 in European Journal of Taxonomy 620 on pages 4-6, DOI: 10.5852/ejt.2020.620, http://zenodo.org/record/3750231