Page 30 - Discover Botswana 24th Edition 2024

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O KAVA N G O
Yet still you would be missing out on an essential and unique element
of the Okavango Delta ecosystem. There exists a mysterious underwater
world seldom seen by more than a few local fishermen and a handful of
adventurous conservationists, ecologists and storytellers who delve deeper
into the waters. A world of predatory plants, fish that crawl on land and
daddy bugs that carry their young on their backs.
Of the 1300 plants in the region, about 200 of them are aquatic including
a fascinating group of bladderworts – ferocious carnivores that use
trapdoors triggered by tiny hairs to snatch up and digest water fleas and
water mites and other small creatures that live in the delta waters. The
ability to catch prey like this gives these carnivorous plants an edge in an
otherwise nutrient poor system.
Only about 80 species of fish are to be found – nothing compared to the
great lakes of east Africa where Lake Malawi alone has more than 1000
species – but where the Okavango comes into its own is in its diversity of
families and genera. 15 families comprising nearly 40 genera include the
weird-looking snout-fish who sense the world around them by emitting
small electrical pulses. There is a plethora of brightly coloured barbs and
top-minnows that grow no longer than your little finger. There are mouth
brooders that keep their young in their mouths for safekeeping, and you
might never even see the labyrinth fish which have air breathing organs in
their gills and spines on their gill-covers that allow them to inch across dry
land on their sides in search of new water.
One could not talk about the diversity of the Okavango delta without
mentioning the aquatic invertebrates. Far less is known about this diverse
group which includes mayfly, dragonfly, caddisfly and fly larvae, crabs,