title: Description of new types of sphaeractinomyxon actinospores (Myxozoa: Myxosporea) from marine tubificid oligochaetes, with a discussion on the validity of the tetraspora and the endocapsa as actinospore collective group names.
abstract: Ten new types of sphaeractinomyxon actinospores are morphologically and molecularly described from the coelomic cavity of two marine oligochaete hosts, Limnodriloides agnes (Hrabě, 1967) and Tubificoides pseudogaster (Dahl, 1960), from Aveiro estuary, Portugal. The smallest sphaeractinomyxon type measured 17 μm (length) × 19 μm (width) × 19 μm (apical diameter), whereas the largest type measured 61 μm × 76 μm × 80 μm. While considering the 10 types of sphaeractinomyxon, it was found that the number of spores developing inside pansporocysts varied between 1, 2, 4, and 8. The total prevalence of infection was of 19 % for the two host species, with a maximum recorded for spring and summer (25-26 %). While considering each type of sphaeractinomyxon individually, it was found that the prevalence values ranged between 0.3 and 1.7 %. All described sphaeractinomyxons were most similar to Myxobolus species. The validity of the tetraspora and endocapsa collective group names is discussed.
authors.affiliation: Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, Edifício FC4, 4169-007, Porto, Portugal. luisfiliperangel@sapo.pt.|Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal. luisfiliperangel@sapo.pt.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Rangel
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Castro
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 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.
authors.forename: Sónia
authors.initials: S
authors.lastname: Rocha
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungária krt. 21, 1143, Budapest, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Cech
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.|Department of Sciences, Institute University of Health Sciences, CESPU, Rua Central da Gandra no. 1317, 4585-116, Gandra, Portugal.
authors.forename: Graça
authors.initials: G
authors.lastname: Casal
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 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.
authors.forename: Carlos
authors.initials: C
authors.lastname: Azevedo
authors.affiliation: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungária krt. 21, 1143, Budapest, Hungary.
authors.forename: Csaba
authors.initials: C
authors.lastname: Székely
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors.forename: Francisca
authors.initials: F
authors.lastname: Cavaleiro
authors.affiliation: Laboratory of Animal Pathology, Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, Edifício FC4, 4169-007, Porto, Portugal.|Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Santos
mesh_terms: D000818:Animals; D063366:Estuaries; D055764:Myxozoa / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification; D009835:Oligochaeta / Q000469:parasitology*; D011174:Portugal / Q000453:epidemiology; D013170:Spores / Q000166:cytology
keywords: Endocapsa; Limnodriloides agnes; Oligochaeta; Sphaeractinomyxon; Tetraspora; Tubificoides pseudogaster