|
|
|
Colney Nature Watch |
A series of articles on the wild life in London Colney |
Pike |
Fishermen have many nicknames for the pike: pond devil, water wolf and fresh water shark are some! But does it deserve its fearsome repuation? We know pike eat baby ducks, and have taken small dogs. We know they have a hearty appetite and like eating fish, which makes them unpopular with water bailiffs. The pike certainly looks a killer with its long, slim body and many pointed teeth. It has large eyes, and the largest pike caught in Britain was over a meter and a half in length. The heaviest pike caught by rod weighed 21.5 kg, and was caught in Llandegfedd Reservoir, Wales. Pike most of all like eating fish, and the easiest ones to catch are ones that are sick or dying. But they will eat any suitable sized animal they can find, which includes amphibians, crayfish, small mammals and ducklings. Pike can live in fast flowing rivers, but best of all, they like rivers that are slow flowing and deep, where they can lurk amongst water weed - almost invisible. Pike have variable body patterns, but most have a pattern of spots or stripes, which are roughly vertical, which make them difficult to see amongst the water weed. The long, slim body has a powerful tail, and you notice the fins are towards the rear of the body. The pike’s method of hunting is to lurk in a place with lots of water weed, but near a patch of open water. As soon as their prey appears in the open water, they lunge forwards - and with their sharp teeth, as long as the prey is not too large to be overcome, its fate is certain. Pike extend in range from the west of Ireland, all the way across Europe and Asia, to the Chinese east coast. Pike are largely solitary, rarely interacting with other pike. But come the breeding season, males and females get together and take part in a nuptial dance, with the females shedding their eggs into the water, and the males spraying their semen over them. This has been filmed several times, but naturalists are finding it increasingly difficult to film pikes' mating ritual, as global warming is making it impossible to predict when mating will take place. Owners of fishing waters think their problems would all be solved it the pike were eliminated, but this is not possible. You could drain a lake, remove and destroy every pike, and restock the water, and the next day, a water bird with fertile pike eggs on its feet could land in the water, to release a new generation of pike. Baby pike eat trout and salmon hatchlings. However pike are cannibals. If large pike are removed - then there will be more baby pike, who will devastate the fish population you are nurturing. Better to keep the large pike, who will go for the larger fish, particularly the ones that are sick or injured. If the pike take the larger fish, there will be more food available for the fish you want. By removing ailing fish, you are removing the weaker fish, who will be unable to put their genes into the fish population. So, for a healthy water, that fishermen will wish to patronise, it would be best to tolerate a few pike. Pike are possibly not the largest fish to be found in British waters. Many Britsh waters provide a home for the wels - the European catfish. It is not a native British species. They tend to lurk on the bottom and can grow to a couple of meters in length in a large lake with a good food supply. I have kept catfish as pets, and they can be trained to come to the surface for food. None of mine grew longer than a few centimeters. Many years ago I visited de Hooge Veluwe, a wild life park in Eastern Holland, and in the lake I saw children feeding catfish with bread. They were all over a meter in length, with eight whiskers round their mouths, and they swam on the surface, with their mouths wide open. So although many claim that pike are our biggest freshwater fish, no one can prove there isn't a larger catfish lurking at the bottom!
Robin Cooper |
|
|
|