Molluscs, Annelid Worms and Crustaceans

Our most common - or at least most obvious - molluscs are probably the Garden Snail Helix aspersa, together with Brown-lipped Snails Cepaea nemoralis in gardens and areas such as the Aldersbrook Exchange Lands. A very uncommon snail was found in 2024 between Aldersbrook Exchange Lands and Wanstead Park -a Roman Snail Helix pomatia. These are usually associated with chalky areas, and this area certainly isn't that. It is more usual to find just the shells, but this one - although not exactly kicking - was quite alive.

Slugs will be familiar to most people from their gardens, and perhaps the most recognisable of these will be the Arion species, either A. ater ater the Large Black Slug, or its variety A. ater rufus the Large Red Slug, which is far less common in this area. There will be other species easily found, but I don't profess to be knowledgable about these. One distinctive species I have been seeing is the Leopard Slug - or Great Grey Slug - Limax maximus, and more recently an invasive species known as the Three-band Garden Slug, which I believe to be Lehmannia valentiana.

Pond-living molluscs are particularly under-represented in this list, many were identified by Derek Mckewan after a pond-dipping exercise during a Wren Group "bio-blitz" on 5th October 2014. After the installation of a new pond in my garden, two species of snail spontaneously arrived: the Common Bladder Snail Physa fontinalis and the Wandering Snail Lymnaea peregra. The Swan Mussel Anodonta cygnaea has for long been known from the Ornamental Waters in the form of shells of dead animals, but during a period when the waters of the Heronry Pond became very low in 2009, live specimens were found.

Apart from a couple of garden worms, Annelid Worms have only been investigated during a pond-dipping exercise carried out under the leadership of Derek McKewan by the Wren Group. He identified three species of the Family Hirudinea - the freshwater leeches - from Perch Pond, Wanstead Park on 5th October 2014.

As for Crustaceans, an American Signal Crayfish Pacifastacus leniusculus was found by Heronry Pond in August 2001, and more have been seen since. In August 2004, a number of dismembered crayfish were found in rough grass just to the east of Alexandra Lake on Wanstead Flats. Is it possible that these had been taken from the lake by predators - perhaps gulls? In 2008, a representative from the angling club that fishes the Basin in Wanstead Golf Course reported that over 50,000 (!) had been caught there over the last few years. Chinese Mitten Crab Eriocheir sinensis have been reported from the River Roding as far north as Redbridge roundabout. The local Guardian Series Newspapers on 23rd October 2008 reported that the Environment Agency had found these crabs at Wanstead and further north. The freshwater shrimp Gammarus lacustris, and a water slater Asellus sp. was found in Perch Pond, Wanstead Park during a bio-blitz exercise and identified by Derek McKewan. The common Water Slater Asellus aquaticus is found in my garden pond. Land-based crustaceans are perhaps more familiar and finds so far are the Common Pill Bug Armadillidium vulgare, the Common Shiny Woodlouse Oniscus asellus, which was found in Wanstead Park, the Common Striped Woodlouse Philoscia muscorum, and the Common Rough Woodlouse Porcellio scaber, both present in my garden in Capel Road.

The species are listed in alphabetical Family order, within which the species is alphabetical.

Family Name Species Status
Agriolimacidae a field slug Deroceras sp. Capel Road garden, 14/03/2014
Arionidae Large Black Slug Arion ater ater Sewage Works, 16/09/2000; Sewage Works, 09/07/2006;
Arionidae Large Red Slug Arion ater rufus Capel Road garden, 02/09/2000
Arionidae Common Garden Slug Arion (distinctus) Wanstead Park 21/06/2008
Arionidae Dusky Slug Arion (subfuscus) Wanstead Flats 21/03/2014
Clausiliidae Two-toothed Door Snail Clausilia bidentata Manor Park Cemetery 28/01/2016
Helicidae Copse Snail Arianta arbustorum Sewage Works site, 11/06/2010; Sewage Works, 24/06/2018 (Penny Evans);
Helicidae White-lipped Snail Cepaea hortensis Capel Road garden, 01/09/2000
Helicidae Brown-lipped Snail Cepaea nemoralis Sewage Works, 06/09/2000; Sewage Works, 06/09/2000; Capel Road garden, 08/05/2006
Helicidae Garden Snail Helix aspersa (Cornu aspersum) Capel Road garden, 13/06/2006
Helicidae Roman Snail Helix pomatia Wanstead Park/Sewage Works area (N6) 06/05/2024
Helicidae Kentish Snail Monacha cantiana Capel Road garden 09/04/2014
Helicidae Hairy Snail Trochulus hispidus Wanstead Flats, 18/02/2016
Hygromiidae Girdled Snail Hygromia cinctella Capel Road front garden 26/09/2017
Lauriidae Cylindrical Whorl Snail Lauria cylindracea ? Capel Road garden, 18/03/2015
Limacidae Yellow Slug Limax flavus Capel Road garden, 14/03/2014; 29/02/2016
Limacidae Tiger, Great Grey or Leopard Slug Limax maximus Capel Road garden, 18/05/2006
Limacidae Three-band Garden Slug Lehmannia valentiana ? Capel Road garden, 14/03/2014
Lymnaeidae Wandering Snail Lymnaea peregra Heronry Pond, 23/04/2011; Perch Pond, Wanstead Park 05/10/2014 (bio-blitz); Capel Road garden pond 2010
Lymnaeidae Great Pond Snail Lymnaea stagnalis Heronry Pond, Wanstead Park, 25/04/2011
Oxychilidae Garlic Glass Snail Oxychilus alliarius Capel Road garden  23/02/2019
Oxychilidae Glossy Glass Snail Oxychilus (navarricus ?)
Capel Road garden, 04/03/2014
Physidae a bladder snail Physa sp. Perch Pond, Wanstead Park 19/06/2010
Physidae Common Bladder Snail Physa fontinalis Capel Road garden pond 2010
Planorbidae Great Ramshorn Snail Planorbarius corneus Heronry Pond, Wanstead Park, 03/04/2005
Planorbidae Ramshorn Planorbis planorbis Heronry Pond, 19/08/2012; Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Sphaeriidae Pea-shell Cockle Pisidium sp. Wanstead Park 05/10/2014 (bio-blitz)
Succineidae Amber Snail Succinea putris Capel Road garden, by pond, 08/07/2010
Unionidae Swan Mussel Anodonta cygnaea Heronry Pond 03/09/2009
Annelid Worms
Family Name Species Status
Redworm Eisenia fetida Capel Road garden 24/11/2020
Common Earthworm Lumbricus terrestris Capel Rd, 23/11/2006; Capel Road garden
Family Name Species Status
Astacidae Signal Crayfish Pacifastacus leniusculus Found in Heronry Pond, Perch Pond (05/10/2014), and as a discarded dead animal by Alexandra Lake on 24/08/2004; reportedly numerous in the Basin
Armadillidiidae Common Pill Bug Armadillidium vulgare City of London Cemetery, 04/05/2008; Aldersbrook Exchange Lands, 09/06/2012
Asellidae Water Slater Asellus aquaticus Present in my Capel Road garden Pond. An Assellus species was found in Perch Pond, Wanstead Park on 05/10/2014 (bio-blitz)
Cladocera (Suborder) Water Flea Cladocera Capel Road garden, 12/11/2015
Cladocera Water Flea Chydorus sphaericus Perch Pond, 18/04/2018
Cyclopidae Cyclops or Water Flea Cyclops Capel Road garden pond, 06/01/2018
Oniscidae Common Shiny Woodlouse Oniscus asellus Wanstead Park, 29/07/2011
Ostracoda (Class) Seed Shrimp Ostracod Capel Road garden, 08/04/2016
Philosciidae Common Striped Woodlouse Philoscia muscorum Capel Road garden, 23/07/2006
Platyarthridae Ant Woodlouse Platyarthrus hoffmannseggii Manor Park Station Platform 4, embankment, 01/05/2022
Porcellioniidae Common Rough Woodlouse Porcellio scaber Capel Road garden, 23/07/2006


In addition the following species have been reported, although not personally seen:

Family Name Species Status
Helicidae Vineyard or Maritime Garden Snail Cernuella virgata Sewage Works, 24/06/2018 Penny Evans
Lymnaeidae Mud Snail Lymnaea glabra Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Sphaeriidae (Bivalves) Horny Orb Mussel Sphaerium corneum Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Sphaeriidae a Pea Mussel Pisidium casertanum Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Sphaeriidae Red Pea Mussel Pisidium personatum Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Sphaeriidae Globular Pea Mussel Pisidium hibernicum Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Sphaeriidae Shining Pea Mussel Pisidium nitidium Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Succineidae Large Amber Snail Succinea putris Sewage Works, 24/06/2018 Penny Evans
Annelid Worms
Family Name Species Status
Hirudinea a freshwater leech Erpobdella octoculata Perch Pond, Wanstead Park, 05/10/2014 (bio-blitz)
Hirudinea a freshwater leech Glossiphonia heteroclita Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Hirudinea a freshwater leech Hemiclepsis marginata Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Family Name Species Status
Gammaridae Freshwater Shrimp Gammarus lacustris Perch Pond, Wanstead Park 05/10/2014 (bio-blitz)
Grapsidae Chinese Mitten Crab Eriocheir sinensis Reported from the River Roding (Guardian Series Newspapers - 23rd October 2008)