Invasion
Invasion Description
1st Record: San Diego/CA/Mission Bay (1965, McDonald 1969, cited by Carlton 1979)
Geographic Extent
San Diego/CA/Mission Bay (1965, McDonald 1969, cited by Carlton 1979; Crooks 1998; Crooks and Khim 1999; Dexter and Crooks 2000; Kushner and Hovel 2006; 2011, California Department of Fish and Wildlife 2014)
Vectors
| Level | Vector |
|---|---|
| Alternate | None |
| Alternate | Ballast Water |
Regional Impacts
| Ecological Impact | Competition | |
| The invasion of Arcuatula senhousia was accompanied by the disappearance of the native bivalve Chione fluctifraga. In experiments, survival and growth of C. fluctifraga and C. undatella was reduced in the presence of A. senhousia's mats. Competition for food with M. senhousia may be a factor in the decline of these suspension-feeding clams (Crooks 2001). In experiments in Mission and San Diego Bays, settling young of A. senhousia out-compete native bivalves (Chione undatella and Laevicardium substriatum) for space, by overgrowing them (Castorani and Hovel 2015). | ||
| Ecological Impact | Habitat Change | |
| Arcuatula senhousia's mats cover large areas of subtidal flats in Mission Bay, San Diego, California. These mats increase the shear strength and stability of the sediment, favoring increased densities of other benthic organisms in the mats, including the tanaid, Leptochelia dubia, and the gastropod Barleia subtenus. The mats provide structure for tube-building organisms such as L. dubia. The mats also concentrate organic matter, favoring deposit-feeding organisms (Crooks 1998; Crooks and Khim 1999). Negative impacts of A. senhousia are not obvious or numerous, but negative correlations were seen with the deposit-feeding bivalve Solen rostriformis, and the polychaetes Euchone limnicola and Diplocirrus sp. (Dexter and Crooks 2000). Alteration of sediments by A. senhousia may be a factor in the decline of Chione fluctifraga and C. undatella (Crooks 2001). | ||
| Ecological Impact | Food/Prey | |
| Arcuatula senhousia populations in Mission Bay decline in a seaward direction, as a result of predation by Spiny Lobsters (Panulirus interruptus) and murex snails (Pteropurpura festiva) (Cheng and Hovel 2011). However, effects on predator populations are not known. | ||
| Ecological Impact | Trophic Cascade | |
| One factor in the replacement of native bivalves by Arcuatula senhousia is that the heavy settlement of the mussel attract native predators(Castorani and Hovel 2015) | ||