Polydorid species (Polychaeta: Spionidae) in south-western Australian waters with special reference to Polydora uncinata and Boccardia knoxi

Abstract

Eight species of polydorid polychaetes were found to inhabit mollusc shells from south-western Australian waters. Numerous individuals of Polydora uncinata were extracted for the first time from the shells of both land-based cultured abalone Haliotis laevigata and H. roei, as well as from natural subtidal H. roei and Chlamys australis. Shells of the oyster Saccostrea commercialis cultured in sea-based systems were infested by Boccardia knoxi which was first recorded in these waters. Polydora aura, Dipolydora giardi, D. armata, D. aciculata and Boccardia proboscidea were common among shells of various natural intertidal and subtidal molluscs. A small number of P. haswelli were extracted from their self-excavated burrows in shells of cultured oysters. Boccardia knoxi and D. aciculata were redescribed based on the newly collected materials. Polydora uncinata and B. knoxi exhibited similar larval development patterns (exolecithotrophy and adelphophagy), iteroparity and longer life span, suggesting a high reproductive potential. This study suggests that further monitoring of polydorid species is needed not only from the viewpoint of marine biology but also to survey the risk invasive species pose to commercially important molluscs in this region and worldwide.

Polydorid polychaetes on farmed molluscs: distribution, spread and factors contributing to their success

“…Similarly, many polydorid species (in cluding non-indigenous and pest species) have been recorded in South Africa (14; e.g. Boonzaaier et al 2014, Williams 2015, Australia (9; Blake & Kudenov 1978, Skeel 1979, Sato-Okoshi et al 2008, Walker 2014Handley & Bergquist 1997, Read & Handley 2004, Read 2010), Chile (6; Sato-Okoshi & Takatsuka 2001, Moreno et al 2006) and Brazil (5; Radashevsky et al 2006). In contrast, only 4 polydorid species have been re corded in China, on 5 hosts (Zhou et al 2010).…”

“…The accumulation in on-shore systems of species producing larvae which emerge at a late stage of development may be a consequence of local recruitment of larvae settling soon after emergence from Wilson 1928, Read 1975, Lleonart 2001, Sato-Okoshi 1998, 1999, Sato-Okoshi et al 2008, were identified as important pests in 5 off-shore systems. In at least 3 of these instances the hosts did not develop from natural spatfall and had been transported from nursery systems (Lleonart et al 2003, Simon 2015.…”

“…Reviews that consider polydorids in general, and shell-infestors associated with cultured molluscs in particular, usually have a regional focus: Chile (SatoOkoshi & Takatsuka (Zhou et al 2010), Australia (Blake & Kudenov 1978, Sato-Okoshi et al 2008, Walker 2011, Walker 2014, New Zealand (Read 2004) and the United States of America (e.g. Blake 1969b).…”

“…The most common shellborers are members of the Polydora-complex, often re ferred to as polydorids (e.g. Blake 1969b, Moreno et al 2006, Radashevsky et al 2006, Sato-Okoshi et al 2008, Boon zaaier et al 2014. While there are rare in stances where high infestations by polydorids occur under natural conditions (e.g.…”

“…For example, in South Africa, Chile and Australasia, farmed molluscs were typically infested by fewer species than are present on wild molluscs occurring close to farms (e.g. Sato-Okoshi & Takatsuka 2001, Simon et al 2006, Sato-Okoshi et al 2008, Simon et al 2010, Simon 2011, Boonzaaier et al 2014, SatoOkoshi et al 2015. Similarly, molluscs grown in on-shore culture systems were infested by fewer species than those grown off-shore (Simon, 2015).…”