Garlic Snail
- Peak month
- May
- Records since 2000
- 4,561
- Scientific name
- Oxychilus alliarius
Northern lucina
- Peak month
- May
- Records since 2000
- 4,539
- Scientific name
- Lucinoma borealis
Flat Top Shell
- Peak month
- September
- Records since 2000
- 4,533
- Scientific name
- Steromphala umbilicalis
Smooth Glass Snail
- Peak month
- April
- Records since 2000
- 4,442
- Scientific name
- Aegopinella nitidula
Tree Slug
- Peak month
- October
- Records since 2000
- 4,439
- Scientific name
- Lehmannia marginata
Copse Snail
- Peak month
- May
- Records since 2000
- 4,382
- Scientific name
- Arianta arbustorum
Wrinkled Rock Borer
- Peak month
- July
- Records since 2000
- 4,289
- Scientific name
- Hiatella arctica
Two-toothed Door Snail
- Peak month
- May
- Records since 2000
- 4,241
- Scientific name
- Clausilia bidentata
Hairy Snail
- Peak month
- May
- Records since 2000
- 4,146
- Scientific name
- Trochulus hispidus
Great Pond Snail
- Peak month
- June
- Records since 2000
- 4,111
- Scientific name
- Lymnaea stagnalis
Slippery Moss Snail
- Peak month
- May
- Records since 2000
- 4,110
- Scientific name
- Cochlicopa lubrica
Elongate abra
- Peak month
- July
- Records since 2000
- 4,086
- Scientific name
- Abra prismatica
Black Arion
- Peak month
- June
- Records since 2000
- 4,041
- Scientific name
- Arion ater
Dog-cockle
- Peak month
- August
- Records since 2000
- 3,971
- Scientific name
- Glycymeris glycymeris
Girdled Snail
- Peak month
- October
- Records since 2000
- 3,950
- Scientific name
- Hygromia cinctella
Blunt Gaper
- Peak month
- July
- Records since 2000
- 3,945
- Scientific name
- Mya truncata
Native Oyster
- Peak month
- September
- Records since 2000
- 3,702
- Scientific name
- Ostrea edulis
Elliptic trough shell
- Peak month
- July
- Records since 2000
- 3,679
- Scientific name
- Spisula elliptica
Horse-mussel
- Peak month
- September
- Records since 2000
- 3,571
- Scientific name
- Modiolus modiolus
Cellar Snail
- Peak month
- May
- Records since 2000
- 3,561
- Scientific name
- Oxychilus cellarius
Kidneybean Thracia
- Peak month
- August
- Records since 2000
- 3,554
- Scientific name
- Thracia phaseolina
Pointed Topsnail
- Peak month
- August
- Records since 2000
- 3,548
- Scientific name
- Steromphala tumida
Lesser Flying Squid
- Peak month
- November
- Records since 2000
- 3,484
- Scientific name
- Todaropsis eblanae
Common Bithynia
- Peak month
- June
- Records since 2000
- 3,450
- Scientific name
- Bithynia tentaculata
Common Chrysalis Snail
- Peak month
- May
- Records since 2000
- 3,445
- Scientific name
- Lauria cylindracea
Freshwater Nerite
- Peak month
- May
- Records since 2000
- 3,393
- Scientific name
- Theodoxus fluviatilis
Zebra Mussel
- Peak month
- May
- Records since 2000
- 3,352
- Scientific name
- Dreissena polymorpha
Crested aeolis
- Peak month
- June
- Records since 2000
- 3,334
- Scientific name
- Antiopella cristata
Bourguignat's Slug
- Peak month
- April
- Records since 2000
- 3,328
- Scientific name
- Arion fasciatus
Banded carpet shell
- Peak month
- August
- Records since 2000
- 3,253
- Scientific name
- Polititapes rhomboides
Smooth Artemis
- Peak month
- June
- Records since 2000
- 3,093
- Scientific name
- Dosinia lupinus
Baltic Tellin
- Peak month
- September
- Records since 2000
- 3,070
- Scientific name
- Macoma balthica
Budapest slug
- Peak month
- April
- Records since 2000
- 3,041
- Scientific name
- Tandonia budapestensis
Durham slug
- Peak month
- September
- Records since 2000
- 3,032
- Scientific name
- Arion flagellus
Netted Dog Whelk
- Peak month
- June
- Records since 2000
- 3,029
- Scientific name
- Tritia reticulata
Large Amber Snail
- Peak month
- June
- Records since 2000
- 2,971
- Scientific name
- Succinea putris
Rough Periwinkle
- Peak month
- September
- Records since 2000
- 2,933
- Scientific name
- Littorina saxatilis
Thick Top Shell
- Peak month
- September
- Records since 2000
- 2,926
- Scientific name
- Phorcus lineatus
Dwarf tellin
- Peak month
- August
- Records since 2000
- 2,920
- Scientific name
- Asbjornsenia pygmaea
Small Gaper
- Peak month
- August
- Records since 2000
- 2,915
- Scientific name
- Sphenia binghami
Pacific oyster, Japanese oyster, Miyagi oyster, Portuguese oyster, Pacific cupped oyster, Immigrant oyster, Giant pacific oyster, Giant oyster, Giant cupped oyster
- Peak month
- May
- Records since 2000
- 2,859
- Scientific name
- Magallana gigas
Gari tellinella
- Peak month
- August
- Records since 2000
- 2,855
- Group
- Molluscs
Rusty Urchin-shell
- Peak month
- June
- Records since 2000
- 2,852
- Scientific name
- Tellimya ferruginosa
Spiny Myrtea
- Peak month
- June
- Records since 2000
- 2,781
- Scientific name
- Myrtea spinifera
Common Bladder Snail
- Peak month
- July
- Records since 2000
- 2,764
- Scientific name
- Physa fontinalis
European physa, Tadpole snail, Bladder snail, Acute bladder snail, Pewter physa
- Peak month
- October
- Records since 2000
- 2,479
- Scientific name
- Physella acuta
Great Ramshorn
- Peak month
- May
- Records since 2000
- 2,449
- Scientific name
- Planorbarius corneus
Ocean Quahog
- Peak month
- May
- Records since 2000
- 2,449
- Scientific name
- Arctica islandica