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

Diseases of Aquatic Organisms

Gary R. Meyer¹  Aimê R. M. Magalhães¹  Helen J. Gurney-Smith¹  Johnson C. Stewart¹  Celene da S. Ivachuk¹  Antonio Figueras¹  Simon R. M. Jones¹  Susan M. Bower¹  Maurício L. Martins¹  Ana L. C. Schaefer¹  Simone Sühnel¹  Vitor A. Pontinha¹ 

关键词: Oocytes;    Ovarian parasite;    Marine bivalve;    Amoeba;   

DOI  :  10.3354/dao02748

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: 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 amoeba belonging to 1 of the 2 families of the order Dactylopodida, possibly related to Paramoeba spp. This study represents the first report of this type of organism in oysters. We found that C. gasar and C. rhizophorae were the most susceptible molluscs to these UOPs.

【 授权许可】

Unknown