Detection of a parasitic amoeba (Order Dactylopodida) in the female gonads of oysters in Brazil

作者：Simone Sühnel, C. S. Ivachuk, ALC Schaefer, V A Pontinha, Maurício Laterça Martins, António Figueras, GR Meyer, SRM Jones, JC Stewart, HJ Gurney-Smith, ARM Magalhães, S. M. Bower · 发表于：Diseases of Aquatic Organisms · 年份：2014 · DOI：10.3354/dao02748 · 被引用次数：10 · 研究领域：Parasite Biology and Host Interactions、Marine Bivalve and Aquaculture Studies、Parasites and Host Interactions

The impacts of oocyte parasites on the reproductive success of molluscs are largely unknown. In this study, we evaluated the presence of gonad parasites in 6 species of marine bivalve molluscs native to southern Brazil. Cultured bivalves included the mangrove oyster Crassostrea gasar (sometimes called C. brasiliana), the brown mussel Perna perna, the lion's paw scallop Nodipecten nodosus and the wing pearl oyster Pteria hirundo. Another species of mangrove oyster, C. rhizophorae, and the carib pointed venus clam Anomalocardia brasiliana (syn. A. flexuosa) were collected from the wild. Molluscs were collected in winter 2009 and summer 2010 for histopathological and molecular evaluation. An unknown ovarian parasite (UOP) was observed in histopathological sections of female gonads of C. gasar and C. rhizophorae. The UOP possessed features suggestive of amoebae, including an irregular outer membrane, frothy cytoplasm, a nucleus with a prominent central nucleolus and a closely associated basophilic parasome. PCR analysis was negative for Marteilioides chungmuensis, Perkinsus spp. and Paramoeba perurans. However, real-time PCR successfully amplified DNA from oyster gonads when using universal Paramoeba spp. primers. Also, conventional PCR amplified DNA using primers specific for Perkinsela amoebae-like organisms (syn. Perkinsiella), which are considered as endosymbionts of Parameoba spp., previously thought to be the parasome. Our results suggest that this UOP is a species of amoeb...