Invasion
Invasion Description
1st record: Newport/RI/unnamed brackish pond (~1865, Leidy 1870)
Geographic Extent
Woods Hole/MA/Nobska Pond; Woods Hole/MA/Vineyard Sound-Buzzards Bay (1900, USNM 17843, U.S. National Museum of Natural History 2007); West Falmouth/MA/Nye Pond; Falmouth/MA/brackish ponds; Marthas Vineyard/MA/brackish ponds (Verrill and Smith 1873); Narragansett Boat Club, Cranston/RI/Providence River (MIT Sea Grant 2003); Newport/RI/unnamed brackish pond (Leidy 1870); East Creek Marina, Jamesport/NY/Peconic Bay (MIT Sea Grant 2003); Essex/CT/Connecticut River estuary (1995, Smith et al. 2002); Hinsdale-Hadley/NH-MA/Connecticut River (Smith et al. 2002); RKM 113-RKM-86/NY/Hudson River (1972, Ristich et al. 1977; Walton 1996; Mills et al. 1997); Philadelphia/PA/Schuylkill River (Leidy 1870); Philadelphia/PA/Fairmount Reservoir (Potts 1884); PA/Delaware River (Bilger et al. 2005); Baltimore County/MD/Middle River (Ruiz et al., unpublished data); Baltimore County/MD/Curtis Creek (Bibbins 1892); Baltimore (Pier 1, Pilot House)/MD/Patapsco River (Ruiz et al., unpublished data); Baltimore (Locust Point)/MD/Patapsco River (Bibbins 1892); Baltimore (Fort Carroll)/MD/Patapsco River; Baltimore area/MD/Chesapeake Bay (Bibbins 1892); Patapsco River (1892, USNM 17843 , U.S. National Museum of Natural History 2007); Baltimore County/MD/Key Bridge (Ruiz et al., unpublished data); Anne Arundel County/MD/Magothy River (Bibbins 1892); Love Point (Kent Island)/MD/Chesapeake Bay (Ruiz et al., unpublished data); Anne Arundel County/MD/Severn River (Bibbins 1892); Edgewater (SERC)/MD/Rhode River; Lower Marlboro/MD/Patuxent River (Cory 1967); Tappahannock/VA/Rappahannock River (Calder 1971); Georgetown/DC/Chesapeake & Ohio Canal (Banta and Backus 1991); Mathias Point/VA/Potomac River; Fort Washington/MD/Potomac River (Bibbins 1892); DC-MD-VA/Potomac River (Spoon 1976); Mattaponi Indian Reservation/VA/York River (Calder 1971); West Point/VA/York River, Mattaponi River (1892, Bibbins 1892); Deep Water Shoal/VA/James River (Calder 1971); Lawnes Point/VA/James River (Calder 1971); Hog Island Point/VA/James River (Calder 1971); Jamestown Island/VA/James River (Calder 1971); NC/Pamlico River (Dean and Bellis 1975)
Vectors
| Level | Vector |
|---|---|
| Probable | Hull Fouling |
Regional Impacts
| Ecological Impact | Competition | |
| Cordylophora caspia is a potential competitor for space in fouling communities. In field experiments on fouling plates (Key Bridge, Patapsco River, Maryland), where laboratory-grown colonies of C. caspia were added, abundances of the bryozoan Victorella pavida (s.l., cryptogenic), and the protozoans Metafolliculina sp., and Stentor sp. were reduced (Von Holle and Ruiz 1997; Ruiz et al. unpublished data). | ||
| Ecological Impact | Habitat Change | |
| Cordylophora caspia colonies are dense and bushy, and constitute a substantial structural alteration to the surfaces of wood, plants, rocks, etc. The hydroid can provide some protection from predators and currents for surrounding organisms. In field experiments, the addition of laboratory-grown colonies of C. caspia resulted in increased abundances of the barnacle Amphibalanus improvisus, the polychaete Alitta succinea, corophiid amphipods, and the introduced entoproct Loxosomatoides laevis on fouling plates (Von Holle and Ruiz 1997; Von Holle unpublished data). | ||
| Ecological Impact | Food/Prey | |
| Cordylophora caspia is eaten by the nudibranchs Tenellia spp. (native T. fuscata and cryptogenic T. aspersa). These nudibranchs can become very abundant on C. caspia, and are apparently limiting factors in C. caspia's abundance and distribution. The relative abundances and distributions of the two nudibranch species in Chesapeake Bay are poorly known (Ruiz et al. unpublished data; Vogel 1977). | ||