Invasion
Invasion Description
1st Record: Berkeley/CA/San Francisco Bay (1938, Carlton 1979; Cohen and Carlton 1995) The date of the first collection is uncertain, and is variously given as 1938 or 1948 (Stohler 1962; Carlton 1979). Carlton offers some evidence supporting the 1938 data.
Geographic Extent
Berkeley/CA/San Francisco Bay (1938, Carlton 1979; Cohen and Carlton 1995); Alameda-Berkeley; Belmont Slough-Candlestick Point/CA/San Francisco Bay (Carlton 1979; Cohen and Carlton 1995); Tiburon Peninsula, Marin County/CA/San Francisco Bay (1953, 1 specimen, Carlton 1979; Cohen and Carlton 1995); 1 mi off Hunters Point, San Francisco/CA/San Francisco Bay: (1930s, CAS 62010, California Academy of Sciences 2013); Alameda County/CA/mouth of Coyote Hills Slough, South San Francisco Bay (1976, CAS 3304, California Academy of Sciences 2013); CA/Bolinas Lagoon (1960s, Carlton 1979, 1 egg string, no animals found)
Vectors
| Level | Vector |
|---|---|
| Alternate | Oyster Accidental |
| Alternate | Pet Release |
| Alternate | Fisheries Accidental (not Oyster) |
Regional Impacts
| Ecological Impact | Habitat Change | |
| The shells of Busycotypus caniculatus of Ilyanassa obsoleta, larger than those of native gastropods, may be facilitating an increase in body size of the native Pagurus hirsutiusculus (Hairy Hermit Crab), whose growth may have been limited by the size of available shells (Wicksten 1977). | ||