Perkinsus mediterraneus n. sp., a protistan parasite of the European flat oyster Ostrea edulis from the Balearic Islands, Mediterranean Sea

Diseases of Aquatic Organisms

Kimberly S. Reece¹  Kathleen Apakupakul¹  Antonio Villalba¹  Amalia Grau¹  Carlos Azevedo¹  Sandra M. Casas¹ 

关键词: Perkinsus mediterraneus n. sp.;    Ostrea edulis;    Oyster parasite;    Ultrastructure;    Zoosporulation;    ssu rRNA gene;    Internal transcribed spacer;    Perkinsus atlanticus;   

DOI  :  10.3354/dao058231

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: A new species, Perkinsus mediterraneus, a protistan parasite of the European oyster Ostrea edulis (L.), farmed along the coast of the Balearic Islands, Mediterranean Sea, is described. Morphological examinations with light andtransmission electron microscopy, DNA sequence-analysis and enlargement in Ray¹s fluid thioglycollate medium (RFTM) confirmed that this parasite belongs to the genus Perkinsus. Specific morphological and genetic characteristics indicated that itshould be considered a new species in the genus. Sequencing of the small subunit ribosomal (ssu rRNA) gene confirmed that the parasite belongs to the genus Perkinsus, and sequences of the internal transcribed spacer (ITS) were distinct from anyPerkinsus ITS sequences previously published and/or deposited in the GenBank. Phylogenetic analysis revealed that the ITS sequences of the new species formed a monophyletic group comprising a sister clade to the P. atlanticus/olsenigroup. In addition, morphological differences were observed between the new species and the other described Perkinsus spp.. After incubation in RFTM for 1 wk, the prezoosporangium had reached an extremely large size (97.4 ± 1.99 µm) (mean ± SE),and after 2 wk incubation had again almost doubled in size (167.1 ± 8.09 µm). The discharge-tube length was one sixth the diameter of the zoosporangium, i.e. a ratio of 17.36:97.38, the lowest ratio observed for any Perkinsus species. At theultrastructural level, zoosporangia and zoospores exhibited some differences compared to other Perkinsus species.

【 授权许可】

Unknown