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The recent wet spell in Kruger had (debatable) beneficial consequences for some... the rising water level causes a spawning urge in the African sharptooth catfish Clarias Gariepinus to start migrating upstream (normally) immediately after the first heavy showers of the rainy season... they love shallow water and vegetation to spawn in.

Such was the case at the causeway below the Pioneer hide near Mopani, Friday 20 November. However, “upstream” is restricted due to the dam wall, so, downstream became a viable second option. The catfish somehow sensed that their pond was overflowing, offering suitable spawning habitat on the downstream side of the causeway. They gathered there in numbers to cross over in the very shallow overflow. Soon the Nile crocodile realised there was one of its favourite food items on offer...


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Somehow the catfish detected the presence of the crocodile as well as that the best places to run the gauntlet being the shallowest part of the causeway.


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There couldn't have been more than 2 cm of water, but it was enough for the catfish to power across the causeway and into the safer portion of the stream where it would eventually participate in a spawning frenzy.


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The croc would react to the splashing, arriving at the catfish's departure point too late to be effective, while behind the crocodile, another catfish would sneak across. Eventually the croc gave up the effort and retreated, leaving the causeway to the catfish.


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Obviously we were rooting for the croc... I mean, the shots of a crocodile catch would have been much more exciting that those of sneaky catfish outmaneuvering the mighty Nile crocodile!

Read more about the effects the rain had on Kruger's animals.

Great episode of Kruger live action
(catfish have more brains then crocs)

super frequency croc/ catfish

Thanks johan van rensburg great pics

No wonder the croc has such a long face
Lovely story and photos Johan!!

Great tale, JvR!! Who knew that fish could strategise

I must say you were clever to work out what was going on JvR ... and no one must tell me fish can only remember for 20 secs (or something like that) as those fish are darn smart!!

Thanks for sharing JvR! Just shows that there is always something interesting going on in nature

I agree with DB on this…I would have sat there and told myself that the poor catfish are desperate to get out of the pond because there is a crocodile in it!

What a fascinating thing to see and you captured it is perfect detail…thank you for sharing this!!

Whaaahahahaaa...

Jeez... maybe YOU are right, Jumbo... Who am I to say they were more bent on proliferation than survival?

Jumbo, bert, Micetta, oddesy, Bennievis, arks and DinkyBird, thanks for the comments and kind compliments.

What a special sighting! thanks for sharing Johan I'm so glad they got away! I'm always sad when I see the poor fish struggle in the muddy shallow puddles during the dry months.

Hi JvR, Excellent description, backed up by photos, of the sequence of events!

Bennievis, you remark re the long face croc...

DB, they have in fact well developed memories, even goldfish!

http://books.google.co.za/books?id=__wt ... ng&f=false

Seems as if water currents are a major environmental factor acting as an orienting influence on spawning migrations.

In 1994, a public experiment at the Palais de la Découverte science museum showed that goldfish could be trained to recognize and to react to light signals of different colors by using positive reinforcement. More recent research by the School of Psychology at the University of Plymouth in 2003[citation needed] demonstrated that goldfish have a memory-span of at least three months and can distinguish between different shapes, colours and sounds. They were trained to push a lever to earn a food reward; when the lever was fixed to work only for an hour a day, the fish soon learned to activate it at the correct time. The Discovery Channel's show Mythbusters tested the contemporary legend that goldfish only had a memory span of 3 seconds and were able to prove that goldfish had a longer memory span than commonly believed. The experiment involved training the fish to navigate a maze. It was evident that they were able to remember the correct path of the maze after more than a month. A study at the start of the 2000s showed that fish do actually respond to certain colours, this is most evident when it comes to feeding as fish are also aware of feeding times provided they are fed at around the same time everyday.

http://en.wikipedia.org/wiki/Goldfish

SC, I am with you on that one. It is not a pretty sight. Even more so when they are picked off one by one by hungry predators.

The African lungfish has survival techniques up its sleeve.

When a drought occurs, the lungfish digs deep into the mud and buries itself. Then the catfish goes into a stupor, stops feeding and becomes inactive. The cocoon of mud keeps the fish from de-hydrating and their inactivity slows their metabolism. Although they may appear to be in great peril, their chances of survival are good because they are prepared to deal with the harsh conditions. They are in a state that allows them to survive with little food or water. After the drought lifts, the water returns and the lungfish becomes active.

http://en.wikipedia.org/wiki/Lungfish

It seems the catfish not so much...

African and Asian clariid catfishes have long been reputed to survive habitat desiccation by remaining dormant under dry mud or sand, in the manner of the lungfish Protopterus. A literature review of aestivation in Clarias species reveals that many of the early accounts are based on hearsay, native superstition or confusion with the lungfish. Recent evidence indicates that clariids may survive whilst buried in moist sand, or in burrows with water-air interface, but that survival is unlikely in dried mud or sand.

http://www.springerlink.com/content/j272206880nrv512/

Super post, Elzet.

Wonderful elaboration on the theme!

Thanks, JvR, except that it seems my elaboration brought this thread to an untimely death.

Just thought I'll let you know that this thread urged me to start a quiz on fish - except that there was one in existence, which was revived by Imberbe - Aquatic Quiz. Why don't you join us over there?

Nope, Elzet. Don't blame yourself for the slow action on this thread. The "Reptile, Amphibians and Fish" corner is closest thing on the forum you'll get to the doldrums... getting ANY action here is to be considered lively Much of what you see here were in any case elicited with a PM to a friend.

The subject matter kinda forced my hand regarding the choice of where to post... Some innovative linking didn't help much either...