Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

Detection of Minchinia occulta in samples of pearl oysters Pinctada maxima infected by Haplosporidium hinei

Bearham, D., Spiers, Z., Jones, J.B.ORCID: 0000-0002-0773-2007 and Nicholls, P.K.ORCID: 0000-0001-7071-3055 (2009) Detection of Minchinia occulta in samples of pearl oysters Pinctada maxima infected by Haplosporidium hinei. Australian Veterinary Journal, 87 (11). pp. 430-437.

PDF - Authors' Version
Download (708kB)
Link to Published Version:
*Subscription may be required


Objective To determine if juvenile pearl oysters (Pinctada maxima) infected with Haplosporidium hinei are also infected with another haplosporidian parasite, Minchinia occulta.

Design Archived samples of pearl oysters infected with H. hinei were examined using polymerase chain reaction (PCR) assays and in situ hybridisation (ISH) to analyse and identify haplosporidians. A 144-bp and 220-bp region of Minchinia DNA were targeted by PCR and amplified DNA from formalin-fixed H. hinei-infected pearl oyster samples was sequenced. A 25-bp oligonucleotide probe targeting a variable section of the parasite's small subunit rRNA gene was used in ISH.

Results The results of DNA-based diagnostic assays supported each other. The sequences obtained by PCR were found to be almost identical to M. occulta from rock oysters and the ISH assay demonstrated infection with M. occulta in affected pearl oysters. ISH indicated a prevalence of infection of 26.7% in one of the previous outbreaks.

Conclusion Pearl oyster spat are susceptible to infection by a Minchinia parasite, most likely M. occulta, which was recently identified in rock oysters within the pearl-producing zones of Western Australia and is associated with mortalities of up to 80% in this species. The occurrence of haplosporidian co-infections in pearl oysters suggests the immunocompetence of juvenile oysters may be an important factor in preventing infection and therefore preventing mortalities such as those occurring in the recent outbreaks of pearl oyster oedema disease.

Item Type: Journal Article
Murdoch Affiliation: Freshwater Fish Group & Fish Health Unit
School of Veterinary and Biomedical Sciences
Publisher: Blackwell Publishing
Copyright: © 2009 Australian Veterinary Association
Item Control Page Item Control Page


Downloads per month over past year