Invasion
Invasion Description
1st record: Waitemata/New Zealand/Waitemata Harbour (1978, Willan 1985; Willan 1987)
Geographic Extent
Waitemata/New Zealand/Waitemata Harbour (1980; Willan 1987); Te Puru/New Zealand/Firth of Thames (1980; Willan 1987); New Zealand/Whangarei Harbour (1985; Willan 1987); Parengarenga/New Zealand/Pacific Ocean (Cranfield et al. 1998); Whangaparoa/New Zealand/Pacific Ocean (Cranfield et al. 1998)
Vectors
| Level | Vector |
|---|---|
| Alternate | Ballast Water |
| Alternate | Hull Fouling |
| Alternate | Oyster Accidental |
Regional Impacts
| Ecological Impact | Competition | |
| Arcuatula senhousia replaced most of the native bivalve fauna in the Tamaki Estuary, North Island, New Zealand (Hayward et al. 2008). Its invasion resulted in the reduction of infauna diversity, particularly bivalves, under mussel mats (Creese et al. 1997). Arcuatula senhousia replaced a subtidal scallop bed. It appears to be competing with, and reducing the abundance of the native mussel Xenostrobus pulex (Willan 1987). | ||
| Ecological Impact | Habitat Change | |
| At lower salinities, shells buffer pH changes resulting from land clearance, causing persistence of some foraminifera in mussel sites. Sites invaded by mussels showed changes in ostracod species composition (Hayward et al. 2008). | ||
| Ecological Impact | Toxic | |
| In 2009, dogs in New Zealand died after consuming a native sea-slug, Pleurobranchaea maculata. The slugs contained high levels of tetradotoxin (TTX), accumulated from predation on Arculatula senhousia, which had been feeding on toxic phytoplankton (Taylor et al. 2015). | ||