title: Ultrastructural description of Ceratomyxa microlepis sp. nov. (phylum Myxozoa): a parasite infecting the gall bladder of Hemiodus microlepis, a freshwater teleost from the Amazon River.
abstract: A new ceratomyxid parasite was examined for taxonomic identification, upon being found infecting the gall bladder of Hemiodus microlepis (Teleostei: Hemiodontidae), a freshwater teleost collected from the Amazon River, Brazil. Light and transmission electron microscopy revealed elongated crescent-shaped spores constituted by two asymmetrical shell valves united along a straight sutural line, each possessing a lateral projection. The spores body measured 5.2 ± 0.4 µm (n = 25) in length and 35.5 ± 0.9 µm (n = 25) in total thickness. The lateral projections were asymmetric, one measuring 18.1 ± 0.5 µm (n = 25) in thickness and the other measuring 17.5 ± 0.5 µm (n = 25) in thickness. Two equal-sized subspherical polar capsules measuring 2.2 ± 0.3 µm in diameter were located at the same level, each possessing a polar filament with 5-6 coils. The sporoplasm was binucleate. Considering the morphometric data analyzed from the microscopic observations, as well as the host species and its geographical location, this paper describes a new myxosporean species, herein named Ceratomyxa microlepis sp. nov.; therefore representing the first description of a freshwater ceratomyxid from the South American region.
authors.affiliation: Departmento de Biologia Celular, Instituto de Ciências Biomédicas, Universidade do Porto, Porto, Portugal. azevedoc@icbas.up.pt
authors.forename: Carlos
authors.initials: C
authors.lastname: Azevedo
authors.forename: Sónia
authors.initials: S
authors.lastname: Rocha
authors.forename: Graça
authors.initials: G
authors.lastname: Casal
authors.forename: Sérgio Carmona
authors.initials: SC
authors.lastname: São Clemente
authors.forename: Patrícia
authors.initials: P
authors.lastname: Matos
authors.forename: Saleh
authors.initials: S
authors.lastname: Al-Quraishy
authors.forename: Edilson
authors.initials: E
authors.lastname: Matos
mesh_terms: D000818:Animals; D001938:Brazil; D005260:Female; D005399:Fishes / Q000469:parasitology*; D005704:Gallbladder / Q000469:parasitology*; D008297:Male; D046529:Microscopy, Electron, Transmission; D055764:Myxozoa / Q000145:classification / Q000302:isolation & purification / Q000648:ultrastructure*; D045483:Rivers