Читать книгу Extreme Nature - Mark Carwardine - Страница 35

NAME	electric eel Electrophorus electricus
LOCATION	South American rivers
ABILITY	stunning prey with electrical discharges

© Andrea Florence/ardea.com

Think of it as a living battery. The electric eel can grow to be more than 2m (6ft 5in) long, but its organs are packed just behind its head, leaving 80 per cent of its body to electricity generation. It’s stacked with up to 6,000 specially adapted muscle cells, or electrocytes, aligned like cells in a battery. Each electrocyte emits low-voltage impulses that together can add up to 600 volts – enough to render a human unconscious. The positive pole is behind the eel’s head, and the negative pole is at the tip of its tail. It tends to remain straight when swimming, using its long ventral fin for propulsion, and so keeps a uniform electric field around itself.

Electricity affects almost every bit of the eel’s behaviour. As well as stunning or killing with high-voltage pulses, it communicates with other eels electrically and uses electrolocation (a sort of electrical bounce-back system) to detect objects and other creatures in the water. Fish and frogs are its staple prey, and it can detect the minute electric currents these and other living things produce. The eel can’t see well, but this doesn’t matter much, since it is mainly nocturnal and tends to live in murky water.

There are other electrified fish, including the related knifefishes, which generate a weak electric field around themselves that they use to sense objects and fish prey and to communicate. The only other shockers are the torpedo ray and the electric catfish, but neither is as shocking as the electric eel.