Invasion History

First Non-native North American Tidal Record: 1907
First Non-native West Coast Tidal Record: 1907
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Tritia obsoleta is native to the Northwest Atlantic, from the Bay of Chaleur, Quebec, in the Gulf of Saint Lawrence to western Florida (Bousfield 1960; Abbott 1974). It was first collected in San Francisco Bay in 1907, where it was introduced with Eastern Oysters (Dall 1907, cited by Carlton 1979) and is now widespread and abundant (Cohen and Carlton 1995; Cohen et al. 2005). It was also introduced to Willapa Bay, Washington and Boundary Bay, British Columbia by 1945 and 1952, respectively. It is established in both bays (Carlton 1979; Wonham and Carlton 2005).

North American Invasion History:

Invasion History on the West Coast:

Tritia obsoleta was first found in beds of newly planted Eastern Oysters (Crassostrea virginica) at Alameda, in San Francisco Bay by W. H. Dall in 1907 (Carlton 1979). It is now the most abundant gastropod on mudflats in San Francisco Bay. It ranges throughout the South and Central bays, and through San Pablo Bay to the Carquinez Straits (Carlton 1979; Nichols and Thompson 1985; Cohen and Carlton 1995; California Academy of Sciences 2008). In San Pablo Bay, it was found at sites from 9.5 to 25 PSU (Filice 1959, cited by Carlton 1979). Surprisingly, this snail has been collected in other California estuaries, but has not become established. Locations (listed from South to North) include: Monterey Bay, Moss Landing Harbor in 1971 (California Academy of Sciences 2008); Bolinas Lagoon in 1925 (Carlton 1979), Tomales Bay in 1930 (MacGinitie 1930, cited by Carlton 1979); Bodega Harbor in 1968 (Carlton 1979), and Humboldt Bay in 1932 (failed, Hanna 1966, Carlton 1979).

Tritia obsoleta was first collected in Willapa Bay, Washington (WA) and Boundary Bay, British Columbia in 1945 and 1952, respectively, but may have been introduced much earlier (1874-1905) with early oyster plantings. Collecting in these areas was sparse in the early 20th century (Carlton 1979). This snail is locally abundant in both bays (Cohen et al. 200; Sakamaki and Richardson 2006), but it has not been reported from Puget Sound, WA or from other locations in British Columbia (Cohen et al. 1998; Gillespie et al. 2007).


Description

Ilyanassa obsoleta (Eastern Mud Snail) is a medium-sized marine and estuarine snail. Its shell is oval, and dextrally coiled, with a well-defined spire, usually eroded at the tip. The adult shell has 6-7 whorls. The parietal wall (inner lip) is thick and glazed with brown and gray. The columella has a spiral ridge near the base. The shell is weakly sculpted with numerous rows of small beads, running roughly at right angles to the growth lines. The outer lip has six small grayish teeth. The shell reaches 25-30 mm. The color of the shell is dark blackish-brown, often overgrown with algae or smeared with mud. The name Ilyanassa obsoleta is widely used, but a molecular analysis found that no genetic distinction between the genera Ilyanassa, Cyclope, and Tritia (Galindo et al. 2016). However, a later analysis restored the distinctness of the genus Ilyanassa (Yang et al. 2021). Escription from: Abbott 1974; Morris 1975; Gosner 1978; and McLean, in Carlton 2007.

Larval development of T. obsoleta is illustrated by Scheltema (1962).


Taxonomy

Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Gastropoda
Subclass:   Prosobranchia
Order:   Neogastropoda
Family:   Nassariidae
Species:   obsoleta

Synonyms

Buccinum noveboracense (Wood, 1828)
Buccinum oliviforme (Kiener, 1834)
Ilyanassa obsoleta (Stimpson, 1865)
Nassa obsoleta (Say, 1822)
Nassarius obsoletus (None, None)
Tritia obsoleta (Galindo et al., 2016)
Ilyanassa obsoleta (Yi et al., 2021)

Potentially Misidentified Species

Caesia fossata
Commonly known as the Giant Western Nassa, native to the West Coast from Vancouver Island to Baja California. Larger, more sculptured, notch between end of columella and outer lip (Abbott 1974, McLean in Carlton 2007).

Ecology

General:

Ilyanassa obsoleta is an estuarine-marine snail, especially associated with mudflats and other soft-sediment habitats. Sexes are separate and animals mature at about 12-14 mm, which in Massachusetts populations is reached in their third summer (Scheltema 1964). Fertilization is internal and eggs are laid in capsules, about 2.7 mm in height, containing about 40-150 eggs (Scheltema 1962). Small, medium, and large females laid means of 31, 55, and 79 egg capsules, respectively (Schwab 2012). The straw-colored capsules are distinctive, armed with spiny flanges, and are attached to the substrate. The eggs hatch into planktotrophic veligers, which take 10-22 days to develop at 17.5 to 25°C. The veligers settle and metamorphose at about 650-750 µm (Scheltema 1962).

Ilyanassa obsoleta spends much of its time on exposed intertidal mudflats where it experiences a wide range of temperatures and salinities. It tolerates temperatures as high as 30°C in water (Vernberg and Vernberg 1969) and probably higher in air when exposed. This snail responds to winter cold by migrating into shallow subtidal waters (Batchelder 1915: Murphy 1979). It tolerates salinities as low as 10 PSU (Carlton 1979; Cohen et al. 2001) and at least as high as 35 PSU, near the ocean, and maybe higher in salt marsh pools. The temperature range for larval development is 16.5 to 28°C and the salinity range is 21-33 (highest tested) PSU (Scheltema 1965).

Ilyanassa obsoleta is an omnivore. Young snails in aquaria graze on algae growing on glass and probably feed by this method in the wild. As they grow, they switch to ingesting large quantities of sediment, together with organic matter and benthic diatoms. They also feed on decaying algae, such as Ulva, and are strongly attracted to carrion, such as dead fish and mollusks. However, they do not attack or feed on living bivalves (Scheltema 1964). This snail is eaten by fishes, crabs, and birds. It is also a host to many species of parasites. Blakeslee et al. (2012) found nine species of trematodes in I obsoleta from its native range, four each with birds or fishes as final hosts, and one infecting a turtle (Diamondback Terrapin, Malaclemys terrapin). Four of these parasites were found in I. obsoleta on the West Coast. (See 'Impacts' section for details.)

Food:

Detritus, Carrion, Algae

Consumers:

Fish, crabs, birds

Competitors:

Littorina littorea

Trophic Status:

Omnivore

Omni

Habitats

General HabitatUnstructured BottomNone
General HabitatOyster ReefNone
General HabitatSalt-brackish marshNone
Salinity RangeMesohaline5-18 PSU
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Tidal RangeMid IntertidalNone
Vertical HabitatEpibenthicNone


Tolerances and Life History Parameters

Minimum Temperature (ºC)0Experimental, limited winter freezing tolerance, response to cold by migrating to deeper water(Murphy 1979)
Maximum Temperature (ºC)30Snails from North Carolina were acclimated at this temperature. A temperature of 37 C resulted in ~50% mortality in 6 hours for unparasitized snails (Vernberg and Vernberg (1969).
Minimum Salinity (‰)10Field and Experimental, inactivity in adults inhibited below 12.5 PSU (Scheltema 1965). But animals abundant at 9-10 PSU (Carlton 1979; Cohen et al. 2001).
Maximum Salinity (‰)35Typical ocean salinity, probably experiences higher salinities in marsh and mudflat pools.
Minimum Reproductive Temperature16.5Temperature for larval development, experimental. No development at 11.5 C. Scheltema 1967)
Maximum Reproductive Temperature28Temperature for larval development, experimental, highest tested (Scheltema 1967)
Minimum Reproductive Salinity20.9Minimum salinity for completion of metamorphosis, not completed at 17.1 ppt (Scheltema 1965)
Minimum Duration10Experimental, larval duration, 25.2 C, beginning of creeping-swimming period (Scheltema 1967)
Maximum Duration22Experimental, larval duration,17.5 C, beginning of creeping-swimming period (Scheltema 1967)
Minimum Length (mm)14Size at maturity (Scheltema 1964)
Maximum Length (mm)30Shells in San Francisco Bay often reach 30 mm (Carlton 1979) but the usually reported maximum for the East Coast is 25 mm (Abbott 1974; Morris 1975).
Broad Temperature RangeNoneCold temperate-Warm temperate
Broad Salinity RangeNoneMesohaline-Euhaline

General Impacts

Tritia obsoleta has developed dense populations on the West Coast. The ecology of this species has been extensively studied on the East Coast, but much less is known about the ecology and impacts of this species on the West Coast. In San Francisco Bay (California), it has displaced the native California Hornshell (Cerithidea californica) from many habitats. In Willapa (Washington) and Boundary Bays (WA/British Columbia), where there are dense populations, and no native equivalents, it may have affected sediment characteristics and foodwebs. However, these impacts have not been studied. The introduction of T. obsoleta resulted in the transport of five digenetic trematode species to San Francisco Bay. Three of these parasites reached Willapa Bay, and two reached Boundary Bay. The adult hosts of these parasites are birds and fishes, but the effects of these parasites on the hosts are not known (Blakeslee et al. 2012).

Economic Impacts

Health: Outbreaks of 'Swimmers Itch' in San Francisco Bay were traced to the cercaria larvae of a blood-fluke (schistosome), Austrobilharzia variglandis, whose intermediate host is Tritia obsoleta. The final host of the trematode is birds, but the cercaria frequently penetrate the skin of bathing humans, where they cannot develop, but do cause itching and irritation. The trematode is believed to have been introduced to the San Francisco Bay with T. obsoleta (Grodhaus and Keh 1958).

Ecological Impacts

Competition: In San Francisco Bay, Tritia obsoleta has displaced the native snail Cerithidea californica (California Hornsnail) in tidal creeks and restricted them to salt pans (i.e. habitats with higher temperatures and more desiccation). These conditions are beyond the tolerance of T. obsoleta, but are tolerated (but are perhaps suboptimal) by C. californica. The mechanism of competition appears to be behavioral interference, in which T. obsoleta move over and bump into C. californica. The native snails respond by withdrawing into their shells, reducing the time available for foraging (Race 1982).

Predation: Tritia obsoleta has reduced recruitment of Cerithidea californica (California Hornsnail) in San Francisco Bay, by consuming C. californica's egg capsules (Race 1982).

Parasite/Predator Vector: The introduction of T. obsoleta resulted in the transport of five digenetic trematode species to the West Coast: Zoogonus lasius (as Z. rubellus); Lepocreadium setiferoides; Stephanostomum tenue; Himasthla quissetensis; and Austrobilharzia variglandis. The first three of these species have fishes as final hosts; the last two have birds (shorebirds, gulls, cormorants, ducks) as final hosts (Blakeslee et al. 2012). All of these parasites are present in San Francisco Bay, while three were found in Willapa Bay, and two in Boundary Bay. The two most widespread parasites, H. quissetensis and A. variglandis are bird-hosted as adults. Impacts of these parasites on their final hosts is unknown.

Regional Impacts

NEP-VNorthern California to Mid Channel IslandsEcological ImpactCompetition
Tritia obsoleta has displaced the native snail Cerithidea californica in San Francisco Bay from tidal creeks. The native snails actively withdraw from T. obsoleta, and are mostly restricted to salt pans, which are frequently subject to high temperatures and desiccation (Race 1982).
NEP-VNorthern California to Mid Channel IslandsEcological ImpactPredation
Tritia obsoleta actively feeds on the egg capsules of the native snail Cerithidea californica in San Francisco Bay (Race 1982)
P090San Francisco BayEcological ImpactCompetition
Tritia obsoleta has displaced the native snail Cerithidea californica in San Francisco Bay from tidal creeks. The native snails actively withdraw from T. obsoleta, and are mostly restricted to salt pans, which are frequently subject to high temperatures and desiccation (Race 1982).
P090San Francisco BayEcological ImpactPredation
Tritia obsoleta actively feeds on the egg capsules of the native snail Cerithidea californica in San Francisco Bay (Race 1982)
NEP-VNorthern California to Mid Channel IslandsEcological ImpactParasite/Predator Vector
The introduction of T. obsoleta resulted in the transport of 5 digenetic trematode species to San Francisco Bay: Zoogonus lasius (as Z. rubellus); Lepocreadium setiferoides; Stephanostomum tenue; Himasthla quissetensis; Austrobilharzia variglandis. The first 3 of these species have fishes as final hosts; the last 2 have birds (shorebirds, gulls, cormorants, ducks) as final hosts (Blakeslee et al. 2012). The effect of these parasites on their final hosts is unknown.
P090San Francisco BayEcological ImpactParasite/Predator Vector
The introduction of T. obsoleta resulted in the transport of 5 digenetic trematode species to San Francisco Bay: Zoogonus lasius (as Z. rubellus); Lepocreadium setiferoides; Stephanostomum tenue; Himasthla quissetensis; Austrobilharzia variglandis. The first 3 of these species have fishes as final hosts; the last 2 have birds (shorebirds, gulls, cormorants, ducks) as final hosts (Blakeslee et al. 2012). The effect of these parasites on their final hosts is unknown.
P270Willapa BayEcological ImpactParasite/Predator Vector
The introduction of T. obsoleta resulted in the transport of 3 digenetic trematode species to Willapa Bay: Zoogonus lasius (as Z. rubellus); Himasthla quissetensis; Austrobilharzia variglandis. The first of these species has fishes as its final hosts; the last 2 have birds (shorebirds, gulls, cormorants, ducks) as final hosts (Blakeslee et al. 2012). The effect of these parasites on their final hosts is unknown.
NEP-IVPuget Sound to Northern CaliforniaEcological ImpactPredation
The introduction of T. obsoleta resulted in the transport of 3 digenetic trematode species to Willapa Bay: Zoogonus lasius (as Z. rubellus); Himasthla quissetensis; Austrobilharzia variglandis. The first of these species has fishes as its final hosts; the last 2 have birds (shorebirds, gulls, cormorants, ducks) as final hosts (Blakeslee et al. 2012). The effect of these parasites on their final hosts is unknown.
P297_CDA_P297 (Strait of Georgia)Ecological ImpactPredation
The introduction of T. obsoleta resulted in the transport of 2 digenetic trematode species to Boundary Bay: Himasthla quissetensis; Austrobilharzia variglandis. These species have birds (shorebirds, gulls, cormorants, ducks) as final hosts (Blakeslee et al. 2012). The effect of these parasites on their final hosts is unknown.
NEP-IIIAlaskan panhandle to N. of Puget SoundEcological ImpactParasite/Predator Vector
The introduction of T. obsoleta resulted in the transport of 2 digenetic trematode species to Boundary Bay: Himasthla quissetensis; Austrobilharzia variglandis. These species have birds (shorebirds, gulls, cormorants, ducks) as final hosts (Blakeslee et al. 2012). The effect of these parasites on their final hosts is unknown.
P090San Francisco BayEconomic ImpactHealth
Tritia obsoleta is an intermediate host of the digenetic trematode (blood-fluke, schistosome) Austrobilharzia variglandis. The final host of the the trematode is birds but the cercaria frequently infect the skin of bathing humans, causing Swimmer's Itch (Grodhaus and Keh 1958).
NEP-VNorthern California to Mid Channel IslandsEconomic ImpactHealth
Tritia obsoleta is an intermediate host of the digenetic trematode (blood-fluke, schistosome) Austrobilharzia variglandis. The final host of the trematode is birds, but the cercaria frequently infect the skin of bathing humans, causing Swimmer's Itch (Grodhaus and Keh 1958).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NA-S3 None 0 Native Estab
NA-ET3 Cape Cod to Cape Hatteras 0 Native Estab
CAR-VII Cape Hatteras to Mid-East Florida 0 Native Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 0 Native Estab
NEP-V Northern California to Mid Channel Islands 1907 Def Estab
NEP-IV Puget Sound to Northern California 1945 Def Estab
NEP-III Alaskan panhandle to N. of Puget Sound 1952 Def Estab
P090 San Francisco Bay 1907 Def Estab
P095 _CDA_P095 (Tomales-Drakes Bay) 1925 Def Failed
P110 Tomales Bay 1930 Def Failed
P112 _CDA_P112 (Bodega Bay) 1968 Def Failed
P130 Humboldt Bay 1932 Def Failed
P270 Willapa Bay 1945 Def Estab
P297 _CDA_P297 (Strait of Georgia) 1952 Def Estab
NA-ET2 Bay of Fundy to Cape Cod 0 Native Estab
P093 _CDA_P093 (San Pablo Bay) 1907 Def Estab
P080 Monterey Bay 1971 Def Failed
NA-ET1 Gulf of St. Lawrence to Bay of Fundy 0 Native Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude
5251 USNM 809637 1978 1978-05-25 St. Simons Island Native 31.1503 -81.3697
5252 USNM 822713 1976 9999-01-01 Sherwood Island State Park Native 41.1000 -73.3000
5253 USNM 888843 1980 1980-07-01 Loveladies Native 39.7237 -74.1338
5254 USNM 1027935 1950 1950-06-01 None Native 41.3000 -71.8000
5255 USNM 1055473 1964 1964-07-22 Norwich Native 41.4000 -72.1000
5256 Field Museum 303015 2002 2002-07-08 Bull Island Native 32.9078 -79.6092
5257 Field Museum 303007 2002 2002-06-08 Chaleston Native 32.7625 -79.9292
5258 Field Museum 282747 1990 1990-06-09 Mamaroneck Harbor Native 40.9389 -73.7156
5259 Field Museum 281587 1997 1997-10-10 St. Catherines Island Native 31.6567 -81.1517
5260 Brenchley and Carlton 1983 1980 1980-07-01 Barnstable Harbor Native 41.7167 -70.2667
5261 Novak et al. 2001 None 9999-01-01 Sage Lot Pond Native 41.5533 -70.5100
5262 Kinlan et al. 1997 1997 1997-08-01 Jehu Pond Native 41.5667 -70.4983
5264 Curtis 1997 1997 9999-01-01 None Native 38.6614 -75.0989
5265 Curtis 1997 None 9999-01-01 None Native 38.6000 -75.1008
5266 Curtis 1997 1985 1985-07-01 Bowers Beach (S. of Murderkill River) Native 39.0583 -75.3972
5267 Curtis 1997 1983 1983-07-01 Canary Creek (inside Roosevelt Inlet) Native 38.7900 -75.1639
5268 Curtis 1997 1995 9999-01-01 North Shores (N. of Rehoboth Beach) Native 38.7208 -75.0764
5269 Curtis 1997 1995 9999-01-01 Thompson Island (N. of Rehoboth Beach) Native 38.6900 -75.0936
5270 Curtis 1997 1983 9999-01-01 Grays Point (Indian River Bay) Native 38.5864 -75.1533
5271 Kelaher et al. 2003 2002 2008-04-02 Flax Pond, Long Island Native 40.9633 -73.1403
5284 Curtis and Hurd 1983 1977 1977-10-26 Henlopen sandflat Native 38.7833 -75.1000
5285 McCurdy et al. 2000 1997 1997-07-19 Starrs Point, Nova Scotia Native 45.1333 -64.3667
5286 Levinton et al. 1994 1986 9999-01-01 West Meadow Creek, Stony Brook Native 40.9386 -73.1408
5287 Conrad et al. 1993 1993 9999-01-01 Mount Desert Island Native 44.3489 -68.3447
5288 Tucker et al. 1997 1997 9999-01-01 Kiawah Island Native 32.6081 -80.0850
5289 Gooch et al. 1972 1969 1969-01-01 Shell Point Native 34.6833 -76.5264
5290 Gooch et al. 1972 1969 1969-01-01 Pivers Island Native 34.7175 -76.6725
5291 Gooch et al. 1972 1969 1969-01-01 Slaughter Beach Native 38.9128 -75.3044
5292 Gooch et al. 1972 1969 1969-01-01 Stamford Native 41.0533 -73.5392
5293 Gooch et al. 1972 1969 1969-01-01 Southport Native 41.1364 -73.2839
5294 Gooch et al. 1972 1969 1969-01-01 Atlantic City Native 39.3642 -74.4233
5295 Carlton 1979 1945 9999-01-01 Willapa Bay Def 46.3733 -123.9575
5301 Carlton 1979 1986 9999-01-01 Alameda Def 37.7653 -122.2406
5302 Nichols and Thompson 1985 1986 9999-01-01 San Francisco Def 37.4419 -122.1419
5305 Gooch et al. 1972 1969 1969-01-01 Old Mill Beach Native 41.3781 -72.5958
5306 Edwards and Welsh 1982 1977 1977-07-01 Branford Harbor Native 41.2517 -72.8264
5307 Murphy and McCausland 1980 1977 1979-04-01 Waterford Native 41.3472 -72.1326
5308 USNM 1028622 1955 1955-05-01 None Native 41.6000 -70.4000
5310 USNM 1034875 1960 1960-09-18 None Native 41.5000 -70.6000
5311 USNM 1034954 1960 1960-10-02 None Native 41.7000 -70.6000
5334 Richmond and Woodin 1996 1996 9999-01-01 None Native 33.3272 -79.1664
5335 Connor and Edgar 1982 1982 9999-01-01 None Native 41.5917 -70.6472
5338 Race 1982 1975 1975-01-01 Newark Def 37.5297 -122.0392
5339 Race 1982 1975 9999-01-01 Fremont Def 37.5483 -121.9875
5350 NOAA 12469 None 9999-01-01 None Native 39.0673 -75.4040
5351 NOAA 123543 None 9999-01-01 None Native 31.4933 -81.2935
5354 NOAA 21499 None 9999-01-01 Charleston Native 32.8068 -79.9352
5356 NOAA 24019 None 9999-01-01 None Native 30.4052 -81.5083
5357 NOAA 26701 None 9999-01-01 None Native 39.1797 -75.3539
5358 NOAA 43253 None 9999-01-01 None Native 39.2499 -75.2879
5359 NOAA 45328 None 9999-01-01 Carolinian Province Native 34.1555 -77.8500
5360 NOAA 46962 None 9999-01-01 None Native 32.7642 -79.9475
5362 NOAA 67932 None 9999-01-01 None Native 33.9530 -77.9368
5363 NOAA 85617 None 9999-01-01 None Native 31.4933 -81.2935
5663 Curtis and Hurd 1979 1978 1978-04-22 Cape Henlopen Native 38.7824 -75.1065
5665 Pace et al. 1979 in Cranford 1988 1979 9999-01-01 Sapelo Island Native 31.4772 -81.2419
5666 Cranford 1988 1984 1984-04-01 Cornwallis River Native 45.0833 -64.3333
5669 Chester et al. 1983 1983 9999-01-01 Beaufort Native 34.7166 -76.6500
5670 Chester et al. 1983 1983 9999-01-01 Morehead City Native 34.7228 -76.7264
5671 Chester et al. 1983 1983 9999-01-01 Calico Creek Native 34.7283 -76.7225
5672 Chester et al. 1983 1983 9999-01-01 Phillips Island Native 34.7317 -76.6867
5673 Chester et al. 1983 1983 9999-01-01 Gallants Channel Native 34.7336 -76.6775
5677 Dexter 1961 1960 1960-08-01 Cape Ann Native 42.6361 -70.6875
5701 Gooding and Le Blanc 2004 2001 2008-02-01 Bald Head Island Native 33.8617 -77.9947
5714 Whitelaw and Zajac 2002 2002 9999-01-01 Milford Native 41.2222 -73.0569
5770 CAS IZ 846 1975 1975-12-28 Pinole Point Def 38.0122 -122.3656
5771 CAS IZ 1035 1977 1977-02-02 Menlo Park, Cooley`s Landing Def 37.4539 -122.1811
5772 CAS IZ 1314 1973 1973-03-14 Carquinez Strait Def 38.0833 -122.2500
5773 CAS IZ 1322 1973 1973-03-07 Redwood City Def 37.4853 -122.2353
5774 CAS IZ 3296 1976 1976-08-26 Coyote Hills Slough Def 37.5628 -122.0731
5775 CAS IZ 3364 1977 1977-08-16 Menlo Park Def 37.4964 -122.1519
5776 CAS IZ 11034 1951 1951-10-06 Davis Point Def 38.0525 -122.2592
5777 CAS IZ 11530 1978 1978-06-21 India Basin Def 37.7361 -122.3694
5778 CAS IZ 19449 1973 1973-12-17 Mare Island Strait Def 38.0997 -122.2647
5779 CAS IZ 85280 1989 9999-01-01 Richmond Def 37.9358 -122.3467
5780 CAS IZ 122585 1973 1973-02-15 Charleston Slough Def 37.4419 -122.0914
5781 CAS IZ 122813 1973 1973-01-31 Foster City Def 37.5586 -122.2700
5782 CAS IZ 122836 1973 1973-01-31 Mowry Slough Def 37.4836 -122.0186
5783 CAS IZ 127975 1922 2022-08-28 Dumbarton Bridge Def 37.5053 -122.1183
5784 CAS IZ 127978 1955 9999-01-01 Palo Alto Yacht Harbor Def 37.4419 -122.1419
5785 CAS IZ 128199 None 9999-01-01 Oakland Def 37.8044 -122.2697
5786 CAS IZ 128828 1951 1951-11-10 Martinez Yacht Harbor Def 38.0272 -122.1361
5787 CAS IZ 129768 1976 1976-01-24 Newark Slough Def 37.5300 -122.0906
5788 CAS IZ 129893 1972 1972-09-14 Fremont Def 37.5483 -121.9875
5789 CAS IZ 130799 1970 1970-08-13 San Rafael Bay Def 37.9639 -122.4764
5790 CAS IZ 137307 1984 1984-10-25 Selby Def 38.0567 -122.2428
5791 CAS IZ 141546 1981 1981-08-04 Steamboat Slough Def 38.2211 -122.4236
5793 CAS IZ 159780 1977 1977-08-21 Islip Township Native 40.7297 -73.2108
5796 Cohen et al. 2001 2000 2000-05-21 Naselle River Bridge Def 46.4347 -123.9022
5797 Cohen et al. 2001 2000 2000-05-22 Omeara Point Def 46.4031 -123.9533
6026 Carlton 1979 1946 1946-01-01 None Def 46.4917 -124.0489
6027 Carlton 1979 1935 1935-01-01 Oakland Def 37.8035 -122.2572
6028 Cohen et al. 2005 2004 9999-01-01 San Leandro Marina Def 37.6966 -122.1932
6770 Bousfield 1960 1960 1960-01-01 None Native 48.0000 -65.7500
36738 California Academy of Sciences Invertebrate Zoolog None Near Key Route Pier, Oakland Def 37.8182 -122.3441

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