One of the most attractive aspects of freshwater pond life is that most of it is hidden. We naturally do not see much of what goes on under the surface, unless we have a special interest. But no pond would be complete without some of the larger creatures. This includes frogs, toads and other amphibians (including their young, such as spawn and tadpoles), fish (both small and large), and all the predators of these animals, like reptiles, birds and many other native animals. We'll continue our exploration of pond life by taking one of the larger inhabitants, the stickleback fish, and exploring how - just by looking after one of these creatures - you are opening your eyes to a whole new world.
First, a Fish
We all know what frogs and toads look like, and most people have had contact, in one way or another, with newts - but how many with sticklebacks? Did you know that sticklebacks make a nest and lay eggs which they guard ferociously, and that there are three types of stickleback, all of which are also found in saltwater? The great thing about these fish is that you can keep them with ease; a small tank, supplied with a little pond weed, and they will be quite happy and, under the right circumstances, breed. However, to keep them successfully also requires a bit of imagination.
How do you feed them? Live food is the only answer - pretty much anything that moves and is small enough to fit in their mouth. The best food, what they naturally eat (and the easiest to supply them with), is mosquito larvae. You will find the larvae, Daphnia, in water butts, small puddles, or any container left in the open and full of rain water (pretty much any puddle left undisturbed for a few days, to be honest). Scoop the eggs up and they will keep happily in just about any container.
Once you have started doing this, you have entered a private little world which can be completely your own. And you can take it as far as you want. Just the process of finding, and then keeping, the right 'food' is an interest in itself - like watching a Cyclops (tiny 'crab') making its way across a jar of water.
Your Own 'Pond'
You can quite easily create your own inside pond for investigating pond life, providing you have the space to put a fish tank. Aquariums for freshwater pond life can be quite small - 20cm by perhaps as little as 15cm. But of course you can only keep the smaller water creatures in these. Sticklebacks, dragonflies - there is suddenly so much more to choose from than is available in pet shops. What's more, it's free! And you can put them back, any time.
For a successful freshwater pond-type tank, you will need some mud (preferably from the pond your specimens came from); then some weed - of which several types are suitable. But perhaps the most efficient in terms of oxygen generation is Canadian pond weed, Elodea cadensis - otherwise known as bottle-brush weed. Make sure one end of the plant is buried in the mud properly, or it will simply float to the surface - rather than drifting lazily in the water.
Tap water can be used to fill the tank, but it's not a great substance to use because of the chlorine added to it. While the chemical has no great effect on the larger creatures, it does tend to kill off the smaller ones. There are ways of neutralising the effects of tap water by obtaining other chemicals - thereby keeping your creatures happier, and alive.
It is wise to remember that larger creatures produce quite a lot of waste products which will poison a system. For this, a regular aquarium-type system with filters may be necessary - if you plan to keep eels and such like. However, stickleback and most of the insects are quite happy without. If the system you have created still appears to be under stress, an oxygen pump with a diffuser stone will probably help; more often than not, this is unnecessary.
Sunlight can make the algal population in your 'pond' bloom. Often this clears up and the water becomes clear again - an integral part of actually being able to see your creatures! But be a little clever with your plants. The higher (larger) plants use nitrogen waste products and produce oxygen (one of the reasons why so many canals become low in oxygen in summer is because they are removed). If you have the right balance you won't get much of a bloom, because the higher plants won't allow the smaller plants to become a nuisance (algae can actually remove oxygen from the water).
Some of the easiest creatures to start investigating are larvae, in particular mosquito or dragonfly. Dragonfly larvae are amazing things - again, live food is a must for them - but pretty strange 1. They'll sit on the bottom of the tank for hours. Just a little movement here and there - then suddenly something small comes a bit close and the jaws shoot out!
Of course the bonus is that they change into adults. For this you need a stick of some kind - preferably something a little coarse which they can use to climb out of the water. Some adult dragonflies, such as the large Libellulids, live as larvae for about three years. The fascinating thing, though, is that if they are disturbed they let go of the stick, fall back into the water and drown. A banging door, another climbing over the top, a heavy gust of wind - all can cause disaster. If successful, though, you have this wonderful dash of colour to greet you as you come home. However, you should have respect for this fierce hunter. Either let it go, or if you wish you can preserve the insect for a collection.
To preserve dragonflies, they must first, unfortunately, be killed2. The best substance used to be carbon tetrachloride, before it was banned. Now dried cherry-laurel leaves crunched up and placed in the bottom of a jar will have the same effect. ?
Once dead, the abdomen must be cleaned, as its contents will make it collapse in on itself. Then the dragonfly must be stuffed. The standard method is to use cotton on a needle. The larger insects will perhaps require a knot to be passed through the abdomen, pulling out the gut - then a straw or something similar is inserted. This sounds pretty gross, but it is a good way of keeping a record of your specimen - one you have perhaps personally raised, perhaps one of many; the others you let go?
Raising the smaller damselflies or caddisflies is also very easy. In fact, it's quite fun. Just make sure there's a good supply of weed in the tank, and that it has a good food content. Their prey is usually the smaller water creatures such as Cyclopsv - maybe Daphnia too if they are smaller. With a good sized tank, prey will reproduce itself too, making for a nice little eco-system you can watch without too much intervention.
Other Interesting Creatures
Snails also make fun subjects. The nice thing about them is that they will live with pretty much anything else quite happily. Do watch out for the larger ones, though, as they will eat anything that is too slow to run away from them when they are hungry. In fact many molluscs, and crustaceans, are great to look after, although some crayfish are cannibals and will again - like large snails - eat practically anything that is not quick enough to get away from them.
The common eel, Anguilla, is another creature that is very easy to keep, but not so aggressive. They are graceful creatures, and intelligent; if they are fed at regular intervals they will soon learn when it's feeding time. Interestingly enough, they will reach a size comparable with that of the container in which they live, and no more, unless moved to a larger habitat. In Leonard Bertin's Eels - A Biological Study, he mentions one particular eel that lived in a granite trough in a farmer's yard for over 20 years and stayed exactly the same size.
These creatures are unbelievable, and their life-cycle is a fantastic story. In the wild, their eggs are laid in the Sargasso Sea, in the north Atlantic Ocean near Bermuda. Here they float at great depths. The first metamorphosis is into a Leptocephalus, which is a leaf-like creature. They then migrate towards their native coast. The next stage is the Glass Elver - completely transparent and about 7cm long. They then become a yellow or green eel for up to seven years, unless something happens. After that they are ready to go back to the deep sea. On the final journey of some 3,000 miles, they do not feed, and then change into a silver eel for the last part of their lives.
Frogs, toads and newts - they don't do much, to be honest. The 'mysterious' one is the newt, because it doesn't have as high a profile as its frog and toad cousins. In the UK there are three species: the palmate, the smooth and the crested. They produce eggs singly - wrapped in water plant leaves; have 'tadpoles' for young; and a relatively interesting mating ritual. They need to leave the water in winter due to the cold, and are protected species in the UK (as are other native amphibians), so collecting them is illegal. Look, but don't touch.
If you want to look after fish, having a small pike in an aquarium is quite something to see. The awesome silver of its flank makes for a splendid sight. However, like many river and lakeside fish, they are susceptible to a number of diseases, so be wary of looking after them. Minnows, beautiful creatures and very trout-like, keep well in an aquarium, but will eat anything they can. Young tench, barbell and the like will all live soundly in a home fish tank. And of course, if necessary, you can be put them back in the wild with ease.
How to Catch your 'Aquaria'
There are a number of problems with catching creatures, the aquaria, for your inside 'pond'. The principal one is how to catch something as fast-moving as dragonfly larvae. The best way is to buy a net. Most of those available from fishing tackle shops will do the job, although you can have one made up for you if you want something a bit stronger. The net needs to be strong because, to be effective, you have to push it through water plants, along muddy bottoms - even gravelly rivers. The last thing you want is for it to bend!
Another type of net is quite easily made: a throw net. Obtain some muslin, make a wire frame and weigh it down with roofing lead. All you need to do then is stand on the side of a pond and throw the thing in; when it sinks, pull it back. You won't get many of the fast-moving creatures, but for Daphnia, Cyclops and the like it's fine. If you're lucky, you'll even get a few Chaoborus - these are incredible to keep; a real science fiction creature if ever there was one.
Of course the last option is the easiest. Remove some water-weed and a bit of mud from a pond beforehand, and put it in a plastic bag. Then simply scoop water by hand - just put it in and grab! Drop your catch into the plastic bag, then, once home, pop it all in your tank. You'll soon see what you've plucked from the pond.
The best places to go are usually those away from human habitation. But every kind of water is good - right from flood overflow ponds3 through to farmers' ditches. Or you could simply just wait a few days after it has rained and hunt about in plain muddy puddles in fields; these are often full of Daphnia, Cyclops, and more.
There are probably many more books on the subject of pond life, but the incredibly detailed work Freshwater Life by John Clegg is a major source and a joy to read4. AD Imm's General Textbook of Entomology will never be surpassed. And for information on dragonflies and their larvae, Cynthia Longfield's The Dragonflies of the British Isles can't be forgotten. The pocket-sized books of Dr Thomas T Macan (such as A Guide to Freshwater Invertebrate Animals and A Key to British Fresh and Brackish Water Gastropods) also come highly recommended for dipping in and out of. The latter are not only handy to take with you on exploratory trips but easy to read.
Away from reading, one of the most interesting organisations involved in the subject of pond life is the Freshwater Biological Association, on Lake Windemere, Cumbria. It actively promotes freshwater biology wherever possible. A registered charity, the organisation encourages amateurs in any way it can. At the time of writing, there are organised annual lectures - where it is often possible to meet many other people engaged in the field. The association's website offers a wide range of reading material, and you can also contact it about any queries you might have. Aside from this organisation, there are many other groups to be found with an interest in the exploration of pond life.
So, why not start now? Go on, go out and find yourself a muddy puddle!