There are around 30 different species of fresh water snails in the UK, many of which, are very small and currently unavailable to buy. However, the two most familiar varieties are Lymnaea Stagnalis (giant pond snails) and Planorbarius Corneus (Rams horn snails). These particular species are the most popular and are easily recognized and often talked about, and sold to pond owners. All snails are prolific breeders and in large numbers, are beneficial in the clearing up of decaying matter and also for keeping different types of algae and blanket weed under control. In recent years, water garden enthusiasts and novices have been weighing up the pros and cons of introducing pond snails into their water gardens but, having worked alongside these fascinating creatures for over 25 years, I can only emphasise how important they are to the whole water garden Eco-system. Not only do they clear up waste but are part of the food chain for many water fowl and other non-water birds, and to top the lot, they are actually quite interesting to watch, especially on a hot summers day when they crawl underneath the water surface feeding on algae as they go. If you take a closer look, you can actually see their mouths opening and closing as they forage for food.
All healthy ponds rely on an ecosystem, a balance of healthy water and pond life. In man-made water-gardens and especially in smaller ponds, this balance can sometimes be difficult to maintain, and occasionally, you can get an infestation of snails. This is not surprising though as pond snails have both male and female sex organs, so are experts in the field of colonization. However, it is usually the smaller wild uncommon species of snails that seem to cause most of the problems. I myself, have never known Rams horns or Giant pond snails to do any more damage in large populations other than to over-nibble a few plants. However, any population infestations are best left alone in the long run as they will naturally correct themselves.
Colonizing and Migrating
Pond snails have an amazing ability to simply turn up in your pond. Visiting birds like Moorhens, Coots, Ducks and Herons can often introduce water weeds to your pond by getting them tangled up on their feet, and lots of these weeds are often home to snail spawn. Snail eggs are usually quite common to spot and are covered in a jelly like substance. Round dots in a flat round Jelly (the size of a five pence) are laid by the Rams Horn snail whilst round dots in a two centimeter long tubular strip, will have been laid by Giant pond snails.
Water snails also have their own way of moving from pond to pond. I personally have been witness to this amazing event only a few times when the conditions have been just right. On a warm summers night after hours of non-stop drizzle or steady rainfall, the pond snails will leave the water and migrate to another pond, traveling anything up to about 50 yards a trip. Its not surprising then that sometimes adult snails just suddenly appear in newly dug or established ponds, so there is no need to introduce them to your neighbor, just sit back and wait for a wet night!
Please visit our online website www.lilieswatergardens.co.uk to see informative articles on all types of pond life and our large range of over 750 interesting, unusual and rare pond and water garden plants available to buy online or from our retail nursery in surrey.