Who Gives A Fish Forums

I've recently returned from an expedition to west/central Africa, where I spent several weeks tracking down aquarium fish under 12 cm in size. We focused on the really small ones, usually half that size or even smaller.

So, what did I observe?

Small fish, it seems, have a fondness for small streams that larger predators find hard to navigate. They thrive in shallow water, often seeking refuge in the shadows of overhanging vegetation. This was a common theme among the characins, tetras, small catfish, dwarf Cichlids, African gouramis, and killies we caught. Conversely, still or stagnant water was largely devoid of fish life. Instead, they seemed to prefer the tranquil areas near rapidly flowing water, and the pools that formed at the end of whitewater riffles. Notably, the water in these areas was consistently well-oxygenated.

I was particularly struck by the abundance of silvery, torpedo-shaped barbs, tetras, and lampeye killies in strongly flowing water. The sheer movement of the water was remarkable.

My previous experiences fishing for aquarium species in southern North America and Central America revealed similar patterns.

Unless you're keeping fish from swamps, you may want to consider the importance of oxygen levels, cover, and water movement in your aquariums. I'm taking the cue and increasing the filter flow in all my tanks.

Fascinating account, graye. What an adventure you've had.

I've always had a hunch that good water movement was key for river species, nice to see that confirmed by your experiences.

It's not just river species, lakes have movement too, even if it's just a gentle flow. I recall catching a beautiful killifish in a tiny puddle, no more than a metre by half a metre in size, and only 15cm deep. I had to scoop out leaves and carefully net the fish, but what struck me was that even this small puddle was fed by a nearby waterfall.

We also sampled a stagnant pond, about 10 metres in diameter and a metre or two deep. The few Epiplatys singa we found were in terrible shape, reminiscent of fish from a tank with neglected water changes. I couldn't help but think of the dry season we're in now, and how the recent rain in nearby Cameroon might bring some relief to these fish trapped in stagnant water. The dry stream beds surrounding the pond told a story of a different time, when the water flowed freely and the fish thrived.

Many fish were surviving in these pools and ponds, but their health was clearly poor compared to those in the shallow streams. It was as if they were stuck in a state of limbo, waiting for the rains to come and set them free. When the rains do come, these trickles will become rivers, and the fish will have a chance to escape and flourish.

I think about the theories we hear about not needing water changes, and how they're often what we want to hear. But when you see the natural habitats of our aquarium fish, you realize that large areas of water are often home to just a few small fish, and the water is always on the move. The water tests from these small, moving streams always came back pristine, a testament to the importance of water movement and quality.

I didn't take many pics, but a few of the guys did - I'll see if I can get them to share.

I'm with barnicle on this one, love to see some photos from your trip, would be awesome to get a glimpse into the environments of these fish.