Here are a selection of ‘freshwater’ shells found near the edge of a local canal. The Asian Clam is a rapidly spreading invasive species which was unknown in Britain before October 1998. Originated in China, Korea, south-eastern Russia, and the Ussuri Basin. The first time it has been recorded in this neck of the woods. There are three cardinal teeth in each valve raditaing from the beaks. The latteral teeth are serrated and flattened.
The Painter’s Mussel, an elongate shell, was used by artists in the past to hold their paints, hence its name.
The Duck Mussel is one of our largest freshwater bivalves. It also occupies the greatest diversity of habitats of any large mussel, including lakes, rivers, streams, ponds and canals.
The River Snail requires water with a high oxygen content.
I don’t tend to post many slugs on this blog, although I have photographed quite a few, because I realise they are probably not everyones favourite animal. Yet I think this particular one with its gold speckling which are chromatophores (pigment cells) catches the eye and stand out amongst a world of slithering slugs.
It is called the Brown Soil Slug (Arion (Kobeltia) distinctus), and I often come across it in the garden.
The 2nd image down shows a slug mite Riccardoella (Proriccardoella) oudemansi crawling just below the mantle. Called the White Slug Mite, it is a parasite which infest the lungs of slugs and snails feeding on the hosts blood.
White-lipped Snail (Cepaea hortensis) – Storm Francis is battering us here in the UK, and after the rain had stopped and with the sun coming out briefly, I popped outside and came across this little one on the side of my planter. Not everyones favourite, I know, but they have a beauty of their very own in colour and form. You do have to zoom in to see what I mean. I believe this one was eating algae or lichen.
It’s an odd thing to say, perhaps, but I feel a stillness and a calm with this simple image of a snail nestled in the fold of a nettle leaf. Maybe it is because there is so much going on in the world right now, so much has happened and is still happening, peoples minds are unsettled and unsure of the future, as a harsh wind of change has circled the globe. The snail appears rested, calm, nestled in the fold of a nettle leaf. Double-click image to enlarge if you wish.
White-lipped Snail (Cepaea hortensis) juvenile – A new generation of snails are appearing in the garden, ready to munch their way through it. This little one has such a delicate and elegant looking shell. Double-click to enlarge image.
I found this juevenile snail today. It is teeny-weeny small. But the startling thing I discovered about it when I got the photos on the PC was that the shell had fine hairs on it. Apparently this helps it stick to the leaves when feeding. Double-click image for a closer look.
Garden Snail (Cornu aspersum) – A common garden snail we may have all seen at one time or another. I do have a thing about their shells, and shells in general. I love the intricate details, the patterns and earthy colours of this one in particular.
Copyright: Peter Hillman
Camera used: Nikon D7200
Date taken: 13th October 2019
Place: Rear garden, Staffordshire
By my plant pot full of moss I have a strip of bark leaning against some heather. Occasionally I will lift it to see what is sheltering in the dark and damp place it helps create there. Clinging to the underneath of the bark I found a 5-7mm (around 1/4 inch) Discus Snail (Discus rotundatus). For such a small creature it has such amazing detail and colours.
One summer’s day I observed this White-lipped Snail Cepaea hortensis as it travelled from leaf to leaf on my crab apple tree. It was very slow going, but how it managed to slide and glide from leaf to leaf without falling off was quite something.
I found this Large Red Slug (Arion (Arion) rufus) wallowing in the ground bird feeder this morning, and wallowing almost as if it did not have a care in the world. Later on when I took this image, it had finally slithered out the feeder, covered in seed. I am sure these eat more of the seed than the birds do.
September 2017, rear garden, Staffordshire, England.
This is the Large Red Slug (Arion (Arion) rufus), and its slimy kind really like to set up camp in my garden to chomp on my plants. Now most people know if you want to reduce the slug population in your garden you can dig a hole in the ground and bury a small container of beer whereby the slugs will be attracted, fall in and will drown their sorrows, and themselves in the process. Another way is to sprinkle salt on them where they will meet a most horrible gooey death. However, contrary to them dying by salt, I came across this one munching on a crisp this afternoon on my back decking, which I thought was quite an odd thing to witness, to say the least.
This was a beef and onion crisp, yes it was salted, and it could not get enough of it. It devoured the lot, and mopped up any remaining crumbs in one sitting. After desert (too disgusting to mention) it casually slid off between a narrow crack in the decking.
Apparently if you are a snail and are in a romantic mood all you need is a large green leaf, some shade, and a mate, of course. I found these pair of Garden Snails (Cornu aspersum) enjoying a romantic moment or two this morning at around 8:00, yet they were still at it over two hours later!
Looks like I am going to have baby snails in a couple of weeks time.
I am always fascinated by the intricacies of shells, and how they have evolved to be so. I can’t help but gaze at the top image in wonderment, marvelling at the beauty and bio-engineering involved in its evolution over hundreds of millions of years. All this to protect and shelter the animal inside which had once been feasting on my garden plants.
Garden Snail (Cornu aspersum) rear garden, Staffordshire, England. August 2017.
This is one tiny snail which I never even knew existed until the other week. The shell grows no longer than 4.4mm (0.2in) long. Note it has only one single tooth in the shell opening (see image below), which helps identify this species, and also it is quite a plumpish looking snail with 5 to 6 whorls and a blunt spire compared to other similar species. The snail itself is fairly dark with pale sides.
They are Ovoviviparous, which means the eggs hatch within the body of the animal, and then they give birth to live young. They can live up to 4 years. Quite common and widespread throughout woods, damp grassland and gardens. It can be seen all year round.
After a fair bit of rain I can expect to find these snails out and about in the daytime, where usually they feed under the safe cover of darkness.
They can be a pest, especially to my bedding plants and the few vegetables I grow, and my Hosta which looks like it has been riddled with bullets. Yet I still find a fascination with these creatures, and how very well evolved they are for surviving on the land, as opposed to their seafaring cousins.
By the Mesozoic Era, some 248 million years ago, some of these gastropods had adapted in such a way they left the marine environment to live in freshwater and terrestrial habitats. And here they are now, munching through my garden after the June rain has fallen.
People maybe surprised to know that molluscs consist of the second largest group of animals on earth after the insects, with some 100,000 species plus. Of this group the gastropods are the largest of the mollusc group, with more than 50,000 species globally. They have been around for at least 500 million years. Their habitats can be marine, freshwater, estuarine, or terrestrial. Included in this class are the shell covered snails. limpets, sea hares, and the shell-less slugs.
The body of the snail consists of a large muscular foot, a visceral hump which is contained within an asymmetrically coiled shell (a univalve) a head with eyes and tentacles, and a mouth that contains a rasping tongue used to remove, crush and grind food. Most species of snail are herbivores, whilst others feed on live prey or carrion. They are mainly active at night so their bodies do not dry out in the sun, and during the day they hide in dark, damp places. Those with shells which not only give them some protection against predation, but also protection from desiccation, hide within them and seal themselves against rocks, stones, or vegetation.
Order: Stylommatophora (Air-breathing Terrestrial Slugs & Snails) This taxon, now considered to be a clade, is a very large group of pulmonate (air-breathing) land snails and slugs. They are characterised by having two pairs of retractile tentacles with eyes located on the tips of the larger tentacles.
Order: Basommatophora (Freshwater Snails) In this order are the air-breathing land snails which are found in ponds, ditches, streams, rivers and shallow lakes. They are characterised by having their eyes located at the base of their non-retractile tentacles, rather than at the tips, as in the true land snails in the order Stylommatophora. The majority of basommatophorans have shells that are thin, translucent, and which are fairly colourless.
Order: Neogastropoda (Whelks, Cones & Tritons) These gastropods are mainly deposit feeders or predators. They all have a well-developed siphon for detecting prey. The larger bottom-dwelling carnivores commonly feed on bivalve molluscs, other gastropods, sea urchins, polychaete worms, and even fish. They will often burrow into the sand to reach their prey.
Order: Neotaenioglossa (New Gastropods) This order of mollusc is believed to have evolved around 70 million years ago during the last days of the dinosaurs. They are characterised by the possession of only one gill, one auricle, one kidney and by siphon. This order is generally considered to be the most advanced of the prosobranch molluscs, which include the familiar whelks.
A pale, translucent slug which is greyish-buff colour, and has a pair of dark lines running along its sides. Length 60 to 90mm.
It can be seen all year-long, and is found in on trees, usually in wet weather. It produces large amounts of watery mucous when disturbed as a defence measure. Common and widespread in woodland in W Britain and Ireland.
Also called the ‘Brown Field Slug’, this has a translucent grey-brown body, although it may be darker. The mantle is usually tinged chestnut, and it usually, but not always, has a pale ring around its respiratory pore. It has a very short keel. The mucus is colourless. Quite a fast-moving slug. Length 25 to 35mm.
This slug can be a significant pest in gardens, allotments and nurseries and will eat many types of plants and seedlings.
Found in woods, but especially parks and gardens. Discovered under logs, stones and paving. Introduced to Britain and Ireland in the early 1930s, and has spread rapidly since 1975 and has become common and widespread.
This slug just loves to eat the bird food I put out, apart from my plants. You can see some probable slug eggs just to the bottom right of its back end.
Also called the ‘Field Slug’ or ‘Grey Field Slug’, this is a fairly variable slug in colouration, but it usually has a pale cream body with a brownish mantle which has a netted appearance. It has a truncated keel. It produces clear mucus in large quantities, but it turns milky white when irritated. Similar to the Arctic Field Slug (Deroceras agreste). Length 35 to 50mm.
A very destructive slug and hated by gardeners for it eats the leaves of many various plants and crops, including seedlings. Found in various habitats including agricultural land, parks and gardens. Common and widespread throughout.
Also called the ‘Great Grey Slug’ or the ‘Giant Garden Slug’, this is a large slug which is yellowish-grey to pinkish in colour, although this can be quite variable, with distinctive dark brown blotches and spots. It has a pronounced dorsal keel, and the sole is whitish. Its mucus is sticky and clear. Length 100 to 150mm.
It feeds on fresh and rotting plants of many kinds, and fungi.
Commonly associated with human habitation, and is found in gardens, cellars and outbuildings. It is also found in damp and shady hedgerows and woods. It hides during the day under logs and stones. Common and widespread.
I have shown the two gaper shells on one post to illustrate how different they are, beginning with the Sand Gaper above.
Sand Gaper (Mya arenaria)
A large and robust bivalve, the shell is oval in shape, the anterior end rounded, the posterior end more pointed. It has concentric ridges and is off-white, grey or light brown in colour. Shell length 15cm.
The Sand Gaper burrows to a depth of 50cm into mud and sandflats, where it filters organic matter from sea water. It is often found in estuaries, and is widespread and locally common.
Blunt Gaper (Mya truncata)
A thick-shelled, robust bivalve, rectangular in shape with a truncate posterior margin. It also has numerous concentric lines and is off-white in colour. Shell length up to 70mm.
It is commonly found in estuaries where it buries itself to a fair depth. Widespread and locally common, especially on the east coast of Britain.
Also called the ‘Irish Yellow Slug’, this is a medium-sized to large slug with a short keel. The body colour varies from pale ochre through to yellow-green to grey. The body has dark blotches or spots. The mucous is colourless. It has grey-blue tentacles. Similar to the Yellow Cellar Slug (Limacus flavus), which is a brighter yellow, has smaller spots and blotches, and has blue tentacles. Length 80 to 130mm.
It feeds on seedlings, vegetables, fungi, lichen, and decaying matter. It will even feed on pet food found indoors and old, damp wallpaper.
Commonly associated with gardens and houses, and it will venture indoors after dark. It prefers dark and moist habitats, and it may frequent cellars, greenhouses and sheds. Common and widespread throughout Britain and Ireland.
The shell of the Common Cockle is cream to pale yellow or brownish, and it has 22-28 radiating ribs crossed by prominant concentric ridges which may bare short spines. Length up to 5cm.
It is found in muddy, sandy and fine gravel shores, from the middle to lower shore. Utilising a muscular foot, it burrows up to 5cm into the sand, and when covered by water they open their shells and extend a pair of short siphons to filter-feed on zooplankton. It can live up to 10 years, and is fished commercially and prayed upon by wading birds. It is common and widespread.