Diseases of Aquatic Organisms
DAO is a hybrid research journal on all aspects of disease phenomena in aquatic organisms.
DOI: https://doi.org/10.3354/dao03049
copiedUltrastructure and phylogeny of Ceratomyxa diplodae (Myxosporea: Ceratomyxidae), from gall bladder of European seabass Dicentrarchus labrax
- Sónia Rocha
- Luís Filipe Rangel
- Ricardo Castro
- Ricardo Severino
- Carlos Azevedo
- Maria João Santos
- Graça Casal
ABSTRACT: The myxosporean parasite Ceratomyxa diplodae Lubat et al. 1989 sensu Sitjà-Bobadilla & Álvarez-Pellitero, 1993, originally described from the annular seabream Diplodus annularis in the Adriatic Sea, has subsequently been reported from several other sparid hosts, and also a moronid fish, the European seabass Dicentrarchus labrax from the Mediterranean Sea. Here, molecular identity and additional morphological data are given for this parasite infecting the gall bladder of D. labrax in a southern Portuguese fish farm. In the bile, disporic plasmodia were spherical to subspherical with a smooth surface membrane. Most myxospores were crescent-shaped, 5.1 ± 0.5 (4.8-6.7) µm long (mean ± SD) and 21.9 ± 1.0 (20.4-23.9) µm thick; a few were more arcuate, 5.7 ± 0.4 (5.3-6.3) µm long and 17.3 ± 1.0 (16.3-19.1) µm thick. The wall consisted of 2 symmetrical valves united along a slightly curved suture line, with moderately tapering to rounded ends. Two spherical polar capsules, measuring 2.9 ± 0.3 (2.5-3.4) µm in diameter, contained a polar filament forming 8 to 9 coils organized in 2 rows. Host species, tissue tropism, and myxospore morphology supported species identification. Phylogenetic analyses of the small subunit ribosomal RNA sequence positioned the parasite among most sparid-infecting Ceratomyxa spp., suggesting the existence of a common ancestor for these species. The acquisition of molecular data from infections of C. diplodae in its original host and in other sparids is essential in order to ascertain if the morphological and biological variations found among reports of this parasite are intra- or inter-specific.
KEYWORDS
Sónia Rocha (Corresponding Author)
- Laboratory of Animal Pathology, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas no. 289, 4050-123 Porto, Portugal
- Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua Jorge Viterbo Ferreira no. 228, 4050-313 Porto, Portugal
Luís Filipe Rangel (Co-author)
- Laboratory of Animal Pathology, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas no. 289, 4050-123 Porto, Portugal
- Department of Biology, Faculty of Sciences (FCUP), University of Porto, Rua do Campo Alegre, s/n, FC4, 4169-007 Porto, Portugal
Ricardo Castro (Co-author)
- Laboratory of Animal Pathology, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas no. 289, 4050-123 Porto, Portugal
Ricardo Severino (Co-author)
- Laboratory of Animal Pathology, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas no. 289, 4050-123 Porto, Portugal
Carlos Azevedo (Co-author)
- Laboratory of Animal Pathology, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas no. 289, 4050-123 Porto, Portugal
- Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua Jorge Viterbo Ferreira no. 228, 4050-313 Porto, Portugal
- Zoology Department, College of Sciences, King Saud University, Riyadh 11451, Saudi Arabia
Maria João Santos (Co-author)
- Laboratory of Animal Pathology, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas no. 289, 4050-123 Porto, Portugal
- Department of Biology, Faculty of Sciences (FCUP), University of Porto, Rua do Campo Alegre, s/n, FC4, 4169-007 Porto, Portugal
Graça Casal (Co-author)
- Laboratory of Animal Pathology, Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Rua dos Bragas no. 289, 4050-123 Porto, Portugal