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The Greatest Show on EarthIndian Nations Council

Other insects like dragonflies, damselflies and mayflies also lay their eggs in the water. On hatching these become nymphs which have gills to absorb oxygen dissolved in the water.

Snails lay eggs all spring and summer. Frogs lay eggs only in early spring. You can find them close to the shore in big clumps with thousands of eggs in them. Each egg is coated with jelly. At first the eggs are round and black. Then they change in shape and look like commas. The commas twitch - they are tiny tadpoles. Within ten days, they will wiggle out of the jelly.

Use a strainer to scoop up some frog's eggs. Put them in a big jar with pond water and cover the jar. Then take it home and watch the eggs develop.

It takes two to three months for a tadpole to become a frog. Hind legs grow first, then front legs. As the tail gets shorter, the tadpole stops breathing under water like a fish. It starts breathing air, like a land animal and soon becomes a grown up frog.

Catch a frog, if you can, and watch it breathe. Its throat goes up and down while it takes in air through its nose.

When you have finished looking at the animals and bugs always return them to the pond by floating them on to a spoon. Do not pick them up with your fingers.

POND PLANTS can be just as fascinating as animals once you know what to look for. Living in water they have to cope with some rather special conditions.

The commonest pond plants are rushes and sedges. Clumps of these plants are always found in damp places. Rushes have round, spiky stems filled with white fluffy pith. They are smooth, with no leaves and bear bunches of brown flowers. Sedges have similar flower spikes and tough pointed leaves which grow out in three directions from a triangular stem. These plants form a dense band along the edge of the pond. Among them you may see the violet blue flag.

A STREAM is water on the move. As it rushes across the countryside it cuts or erodes a notch or valley for itself.  To see the effect of water erosion, look for a bend in the stream. The bank on the outside of the bend is being cut away. Debris is deposited on the inside bank creating a beach.

Find out how fast the water is flowing by marking a 5 yard length of the stream. Note the time taken for a small piece of wood to float this distance. Divide the time by five to give the rate of flow in seconds per yard.

Animals that live in streams have to be able to survive the current. They are either strong swimmers like freshwater shrimps and fish or clingers like leeches and flatworms.

Flowing water is better at taking oxygen from the air than still water. Animals must have oxygen to breathe and many stream creatures need lots of it.

The plants are firmly rooted in the stream bed or securely attached to stones. They have long stems and like water milfoil finely divided leaves which do not obstruct the water's flow. Some plants like broad-leaved pondweed have fine submerged leaves and broad floating leaves.

Fish like sticklebacks and young eels weave their way among the weeds. Mayfly and stonefly nymphs dart around while snails and flatworms glide over the stones.

Investigating Fish

Everyone who dips in a pond or stream hopes to catch a fish, but they are not always easy to find. Fish are sensitive to movement and vibrations. They can feel you walking along the bank and see your shadow if it falls on the water. Attract the fish by baiting with small pieces of bread or worms. Some fish always rise to take insects which land accidentally on the surface and become trapped. Insects struggling to escape attract these fish. This is imitated in fly-fishing. Other fish stay near the bottom of the pond, feeding on insects and snails.

Find a bridge over a clear fast-flowing stream. Watch how the fish swim against the current. They are well camouflaged to avoid predators and have more streamlined shapes than fish in ponds.

If you want to catch fish and then release them unharmed remove the barb on your hook as shown in picture.

Page XBugs, Bark, Birds, and Boys

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