Improved diagnostic methods for endemic and exotic pathogens of aquatic animals have been identified as a Key Research Area in the 2009-12 FRDC AAHS R&D plan (6.2.3 Endemic and exotic aquatic animal disease diagnostics).

Since Perkinsus olseni was first described in Australian abalone by Lester and Davies in 1981, histology and culture in Ray’s medium have been the most commonly applied diagnostic procedures for detection of Perkinsus sp.. Although these tests are relatively straight forward and practical, they are general in nature and neither identifies or differentiates specific species of Perkinsus. Despite a well developed framework for the molecular characterization of Perkinsus and modern PCR based molecular tests for some of the more commercially important Perkinsus species, these have rarely been applied in Australia. The first attempts to apply molecular methods to a small number (n=40) of Perkinsus infected abalone from disease outbreaks in NSW have already revealed a new variant which probably represents a new previously unrecognized species in Australia (Reece et al. 2010). This fact and the apparent variation in pathogenicity observed with Perkinsus in different areas, has raised several questions about which Perkinsus sp. are present in commercial mollusc populations.

Given that a significant depletion of blacklip abalone (Haliotis rubra) stocks in NSW over the last 20 years has been attributed to infection with Perkinsus (FRDC Project 2004/084) and localized areas of infection occur in a number of Australian states, from South Australia to northern Western Australia, the development and implementation of highly sensitive and rapid PCR based molecular methods to identify specific species of Perkinsus is essential. The development and application of such tests is necessarily underpinned by a detailed understanding of the molecular makeup of Perkinsus in these populations which is the subject of this application.