Ellipsomyxa arariensis n. sp. (Myxozoa: Ceratomyxidae), a new myxozoan parasite of Pygocentrus nattereri Kner, 1858 (Teleostei: Characidae) and Pimelodus ornatus Kner, 1858 (Teleostei: Pimelodidae) from Marajó Island, in the Brazilian Amazon region

Abstract

Ellipsomyxa arariensis n. sp. was found in the gallbladder of Pygocentrus nattereri Kner, 1858 and Pimelodus ornatus Kner, 1858 from the Arari River on Marajó Island in Pará, Brazil. The new species has disporous plasmodium that varies in size and shape, with ellipsoidal mature spores in the sutural view that have a curved suture line. The spores are 12.6 (12.0-13.4) μm in length and 7.3 (6.7-8.0) μm in width. The two polar capsules present in the spore are pyriform and of equal size, with subterminal openings that project in opposite directions. The polar capsules are 3.5 (3.4-4.0) μm long and 2.6 (2.5-3.2) μm wide. Based on the partial sequences of the SSU rRNA gene of the Ellipsomyxa arariensis n. sp. spores found in Pygocentrus nattereri Kner, 1858 (1325 bps) and Pimelodus ornatus Kner, 1858 (1240 bps), the new species is clearly distinct from all the other myxozoan sequences deposited in GenBank. Based on Bayesian inference and p distances, the new species belongs to the "Ellipsomyxa clade", together with all the other Ellipsomxa species, reinforcing the monophyletic status of this genus. Overall, the morphological data and the partial sequences of the SSU rRNA gene provide a conclusive diagnosis of Ellipsomyxa arariensis n. sp. as a species distinct from all the other Ellipsomyxa species described previously.

Pathological and immunological analyses of Thelohanellus kitauei (Myxozoa:Myxosporea) infection in the scattered mirror carp, Cyprinus carpio

“…Myxozoans (phylum Myxozoa Grasse) have long been regarded as a class of protozoa, but more recent evidence suggests that they are highly differentiated metazoan parasites that infect invertebrates and aquatic animals as the main hosts 26–28 . Metazoans predominantly infect fish 26 , with limited activity on platyhelminth, reptiles, and amphibians 29,30 . Myxozoans are reported to exert parasitic activity in both organ tissues and cavities 31–35 .…”

Artificial blood-feeding of phlebotomines (Diptera: Psychodidae: Phlebotominae): is it time to repurpose biological membranes in light of ethical concerns?

“…Five- to 10-mm membrane fragments were dissected under a stereomicroscope and fixed in Davidson’s solution for 24 h before being processed using standard techniques for embedding in paraffin [ 33 , 34 ]. Two 5-μm serial sections were prepared [ 32 ] using a Microm HM 315 microtome (Microm, Walldorf, Germany), deparaffinized and stained on glass slides with haematoxylin–eosin [ 35 ].…”

Sphaerospora festivus n. sp., a parasite of the flag cichlid, Mesonauta festivus (Teleostei: Cichlidae) from eastern Amazon, Brazil

“…Fragments of the urinary bladder were processed using standard histological techniques for embedding in paraffin, and were stained with hematoxylin and eosin (H&E) and Zielh-Neelsen. Fragments containing myxospores of eukaryote microparasites were collected for molecular analyses, for which they were stored in a freezer in 80% ethanol, following the protocol of Matos et al (2018) and Silva et al (2018).…”