Untitled

Abstract

Ostrea angasi is the only large native ostreine species in southern Australian waters (i.e. New South Wales, Victoria, Tasmania, South Australia and Western Australia (WA)). It has also been recorded as a fossil from Late Pliocene calcarenites of the Roe Plain along the south-eastern coast of WA. Wild populations were harvested for food before and after European settlement. A sample of flat oysters from Oyster Harbour, Albany, WA, was typed for 16S and cytochrome oxidase 1 (CO1) mitochondrial (mt) DNA markers previously shown to be diagnostic for species of Ostreidae. Ostrea edulis was identified in the sample at an approximate 30% occurrence with O. angasi. Interspecific partial 16S and CO1 mtDNA sequence divergences, estimated using Kimura's two-parameter model, were 0.83% and 1.45%, respectively. The occurrence of O. edulis among native O. angasi populations has not hitherto been suspected and, thus, there has not been a legitimate morphological separation of the two. These results emphasise the value of molecular markers in: (1) discriminating morphologically plastic and closely related species; and, thus (2) the monitoring of species introduced into morphologically similar stocks. We caution against such introductions because of the possibility of the importation of oyster diseases (e.g. bonamiasis) and of this and other adverse impacts upon native species.

Bonamia ostreae in the New Zealand oyster Ostrea chilensis: a new host and geographic record for this haplosporidian parasite

“…Flat oysters of the genus Ostrea are similar in appearance (Morton et al 2003) and should such a host have arrived in New Zealand, either through anthropogenic or natural (O'Foighil et al 1999) means, it could easily have gone undetected among native species (Morton et al 2003). In this re spect, O. edulis and O. chilensis are difficult to distinguish by morphology.…”

Complete mitochondrial DNA sequence of the European flat oyster Ostrea edulis confirms Ostreidae classification

“…Recent studies have provided a more comprehensive picture of the cupped oyster genome, showing an unusually high conservation of mitochondrial gene order in Asian Crassostrea species [11]. Even though molecular tools, such as mitochondrial or microsatellite markers, already exist for the European flat oyster and allow population genetics [12] or quantitative genetics [13] studies, the complete characterization of its mtDNA will allow a better study to be made of phylogenetic relationships among members of the genus, especially between the closely-related species O. edulis and O. angasi [14], to improve classification of the Ostreidae family within the Bivalvia.…”

An environmental DNA approach to informing restoration of the functionally extinct oyster, Ostrea angasi

“…A species-specific qPCR assay was developed to target a 141-base pair region of the O. angasi CO1 mitochondrial gene. The nucleotide sequence of this region was obtained from the NCBI GenBank database in accession numbers AF540598 (Morton, Lam & Slack-Smith, 2003), AF112287 (Foighil et al, 1999) and DQ078638-DQ078668 (Hurwood, Heasman & Mather, 2005).…”