Morphology and Phylogeny of Thelohanellus marginatus n. sp. (Myxozoa: Myxosporea), a Parasite Infecting the Gills of the Fish Hypophthalmus marginatus (Teleostei: Pimelodidae) in the Amazon River. (21st August 2014)

• Record Type: Journal Article
• Authors: Rocha, Sónia; Casal, Graça; Velasco, Michele; Alves, Ângela; Matos, Edilson; Al‐Quraishy, Saleh; Azevedo, Carlos
• Is Part Of: Journal of eukaryotic microbiology. Volume 61:Number 6(2014:Nov./Dec.)
• Page Start: 586
• Page End: 593
• Publication Date: 2014-08-21
• Subjects: Protista -- Periodicals; Eukaryotic cells -- Periodicals; Microbiology -- Periodicals; 579.05
• DOI: 10.1111/jeu.12136
• Languages: English
• ISSNs: 1066-5234

Abstract

<abstract abstract-type="main" id="jeu12136-abs-0001"> <title>Abstract</title> <p> <italic>Thelohanellus marginatus</italic> n. sp., a new myxosporean parasite infecting the primary gill filaments of the teleost fish <italic>Hypophthalmus marginatus</italic> (Pimelodidae) in the Amazon River, is described on the basis of microscopic and molecular procedures. The parasite forms whitish and ellipsoidal cysts up to 250 μm in diam. Myxospores ellipsoidal with a slightly more pointed anterior end, measuring 17.1 ± 0.6 μm in length, 6.9 ± 0.4 μm in width, and 5.1 ± 0.5 μm in thickness. A single pyriform polar capsule, 9.0 ± 0.3 μm long and 6.1 ± 0.4 μm wide, positioned slightly right to the medial plane in valvular view, contains a polar filament arranged in 4–5 coils. Molecular analysis of the SSU rRNA gene by Maximum Parsimony, Neighbor‐Joining, and Maximum Likelihood revealed the parasite clustering among other myxobolids, namely <italic>Henneguya</italic> and <italic>Myxobolus</italic>. Host affinity is supported as an important evolutionary signal for the phylogeny of myxobolids. The parasite here described represents the first record of the genus <italic>Thelohanellus</italic> Kudo, 1933 from the South American fauna.</p> </abstract>