Tuesday, 18 August 2015 00:00

The Electrical Catfish of Zambezi

Written by 
A Sri-Lankan Catfish A Sri-Lankan Catfish BY by Peter van der Sluijs, Wikimedia Commons

Kalene hills, Zambia - Thunder and beauty. These are the two words that come to mind when the Zambezi River begins its epic journey in the bosoms of Zambia’s Kalene hills. Although the thunder of Victoria Falls is still silent at the source of the river, the beauty is just as loud.

The river’s marathon expedition takes it into Angola, but the waters miss their country of origin so much that they flow back into Zambia. After that, the iconic river thunders on along the borders of Namibia, Botswana and Zimbabwe then gushes into Mozambique before surging into the Indian Ocean.

All through its journey, the gushing, hissing waters of Zambezi are accompanied by at least 239 species of fish.

Amongst these fish is the electric catfish. It prowls the silent deeps like Zambia’s friendly lions, hunting at night and hiding during the day. If it were not a fish, it might have been a lion or a cheetah, for it possesses a lethal secret weapon like these two cats. It may not have the speed of a cheetah or the regal ferocity of a lion, but its secret weapon is in a class of its own.

Its 3 - 5 kilos of body mass are no match to Vundu, Zambezi River’s largest fish. But don’t mess with the electric catfish on account of its smaller size because that secret weapon will deal with you painfully if you do. As it swims in the lower Zambezi, the electric catfish sometimes comes face to face with the Cornish jack, another fish that possesses a similar secret weapon.

When the catfish is hungry, it races through the dark waters in search of a meal. Any meal. It’s not a choosy diner and will eat whichever hapless fish that happens to cross into its path during its nocturnal prowl.

The secret weapon of this particular catfish is literally electric – it can emit up to 600 volts of electricity though other estimates place this lower. That’s why it is known as the electric catfish aka malapterurus electricus.

This jolt of electricity is its hunting and defense rifle. In this regard, in discharges naturally what Kariba hydroelectric dam, Cahora Bassa dam and several other dams in the river discharge artificially. These dams have a total capacity of nearly 5000 MW, almost five times as much as Kenya’s total installed hydroelectricity capacity. This makes Zambezi a truly electric river with truly electric fish!

The electricity of the catfish has already found its way into African universities. Hangnilo Robert and a team of researchers from a university in Benin were able to light up an LED bulb using electricity discharged by a very small electric catfish weighing only 19 grammes. This success made them to conclude that, ‘the feasibility of an energy farming centered on that catfish is quite conceivable.’

If the researchers’ conclusion proves accurate, then electric catfishes might just give Kariba and Cahora Bassa dams a run for their money! That may be a long way in the future but the seed of possibility is there.

Like a leopard, numerous dark spots dot the body of an electric catfish. Fishermen who have reached out to touch these spots have ended up with electric shocks that left them numb and perplexed. These fishermen span the length and breadth of Africa wherever the electric catfish occurs in the continent’s major river basins like Senegal, Niger and Zambezi. The unique catfish also electrifies Lakes Turkana, Chad, Albert, Kainji and Tanganyika. It is therefore fair to say that this catfish is a truly pan-African fish that would make Kwame Nkrumah proud!

It may not be critically endangered like the banded neolebias of the upper Zambezi, but it’s not exactly over-abundant either. We however shouldn’t wait until it is endangered to start racing to its rescue. Instead of reacting with such crisis management when it is already too late, now is the time to ensure that the electric catfish doesn’t slither onto the endangered list.

Incidentally, the banded neolebias which is just below one inch long, may be a dwarf in the fish world, but it is a giant in the overall world of biodiversity. It is only found in the Kataba stream and its tributary, the Sianda stream, in upper Zambezi. This tiny fish isn’t a massive beast like the mammoth whales that are found downstream in the Indian Ocean but it is dangerously close to extinction. If this sounds alarmist, it is because the alarm went off a long time ago.

The electric catfish seems oblivious or indifferent to its smaller cousin’s woes. A quick glance at its wide mouth leaves one with the impression that it is either grinning or sneering, as if wondering why the banded neolebias can’t just heed the divine call to multiply and fill the river.

Indeed, the electric catfish has a lot to grin and sneer about. For starters, this mammoth river in which it swims is Africa’s fourth longest river and meets the needs of at least thirty million people in the Zambezi River basin. Apart from feeding and enhancing the livelihoods of millions, this river has also given the world one of the seven natural wonders – Victoria Falls, known locally as Mosi-oa-Tunya meaning, ‘smoke that thunders.’ These falls are without doubt a divine smoke of dazzling beauty that has shocked even the electric catfish, the master of shocks.

The catfish also grins about the major wetlands and Ramsar sites in the river basin. They include Barotse floodplains in Zambia, Chobe swamps in Namibia, Linyanti swamp in Botswana and Busanga swamp in Zambia. The wetlands are golden chicken that lay golden eggs, contributing immensely to ecotourism, wildlife, fishing, grazing plus a host of other ecosystem products and services. Indeed, the basin’s natural capital is simply staggering, greatly supporting economic activities in agriculture, mining, forestry, tourism and manufacturing.  

The sneer of the catfish mostly has to do with human attitudes and activities that are harming the vast Zambezi river basin. It wonders silently, ‘how can you starve and harm the very chicken that is laying golden eggs for you?’

The wetlands are as fragile as they are priceless. Is this fragility being managed properly?

The hydroelectric dams are the biggest consumers of the rivers water. Is this ultimately sustainable?

Riverine communities have lived next to the river for centuries. Is their indigenous knowledge being fully tapped into?

The catfish has no answers to these questions. Together with all the other fish in the river, it is a fundamental part of the entire Zambezi River ecosystem. It is also unique amongst the fish. How many other fish can boast of the ability to electrically shock both prey and assailant?

Fishers are its primary assailants and from time to time, the catfish ends up entangled in a fishing net or biting a fishing hook. Because it can live up to ten years, many are the times that it evades fishers’ traps. But when its luck runs out, the catfish becomes a delicacy. It is a popular meal amongst many fishing communities.

In 1951, British zoologist Hans Lissmann described the electric catfish quite colorfully. He wrote that they have the ‘appearance of a rather rigid sausage propelled by somewhat ostraciform movements.’

 

Alas, the electric catfish is akin to a swimming sausage that discharges electricity. Not bad for a fish that is not particularly pretty. But like romantic love at its apex, its touch sends instant shockwaves.

DJ Bwakali

Words can inspire action and change the world

Login to post comments