title: Ortholinea auratae n. sp. (Myxozoa, Ortholineidae) infecting the urinary bladder of the gilthead seabream Sparus aurata (Teleostei, Sparidae), in a Portuguese fish farm.
abstract: A new myxosporean species, Ortholinea auratae n. sp., is described from the gilthead seabream, Sparus aurata Linnaeus, 1758 (Teleostei, Sparidae) from a fish farm in Algarve, Portugal. Plasmodia and spores were found in the urinary bladder and, less frequently, in the posterior kidney. Plasmodia were polymorphic, presenting an irregular cellular membrane due to the presence of several peripheral projections, which in turn were covered by a glycocalyx-like sheet. Mature spores were subspherical in valvular view and ellipsoidal in sutural view, measuring 9.0 ± 0.3 (8.2-10.1) μm in length, 8.3 ± 0.4 (7.5-9.1) μm in width, and 7.2 ± 0.5 (6.3-8.4) μm in thickness. The two valves comprising the spores displayed an intricate pattern of surface ridges and were also enveloped by a glycocalyx-like sheet. Two subspherical polar capsules, 3.2 ± 0.1 (2.9-3.6) μm long and 2.7 ± 0.1 (2.4-2.9) μm wide, were located at the anterior pole and displayed divergent orientation. The polar filament coiled in three to four turns. The comprehensive analysis of the parasite's ultrastructural observations and molecular data for the small subunit (SSU) ribosomal DNA (rDNA) gene identify O. auratae n. sp. as a new species, clustering together with other myxosporeans infecting the excretory system to form a subclade of the main freshwater clade.
authors.affiliation: Faculty of Sciences, Department of Biology, University of Porto, Rua do Campo Alegre, s/n, Edifício FC4, 4169-007, Porto, Portugal, luisfiliperangel@sapo.pt.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Rangel
authors.forename: Sónia
authors.initials: S
authors.lastname: Rocha
authors.forename: Muhammad H
authors.initials: MH
authors.lastname: Borkhanuddin
authors.forename: Gábor
authors.initials: G
authors.lastname: Cech
authors.forename: Ricardo
authors.initials: R
authors.lastname: Castro
authors.forename: Graça
authors.initials: G
authors.lastname: Casal
authors.forename: Carlos
authors.initials: C
authors.lastname: Azevedo
authors.forename: Ricardo
authors.initials: R
authors.lastname: Severino
authors.forename: Csaba
authors.initials: C
authors.lastname: Székely
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Santos
mesh_terms: D000818:Animals; D004275:DNA, Ribosomal / Q000235:genetics; D005393:Fish Diseases / Q000453:epidemiology / Q000469:parasitology*; D055764:Myxozoa / Q000145:classification* / Q000235:genetics; D010273:Parasitic Diseases, Animal / Q000453:epidemiology / Q000469:parasitology*; D010802:Phylogeny; D011174:Portugal / Q000453:epidemiology; D021541:Sea Bream; D001743:Urinary Bladder / Q000469:parasitology*
chemical_list: D004275:DNA, Ribosomal