Corydoras are one of the most popular aquarium fish in the world and they are often one of the first egglayers fishkeepers actually see breeding. It is a truly remarkable sight watching a group of these catfish indulge in an orgy!
PHOTOGRAPHS: AREND VAN DEN NIEUWENHUIZEN

Breeding Corydoras

For many of us the wonder of watching these fish breed is enough but for the more scientific enthusiast the question of how they fertilise their eggs has always hung in the air like a question mark hovering over the hobby as a whole. Just how they spawn has been photographed frequently (although rarely as explicitly as with these photographs of Arend’s ) but how sperm and egg get together has never been answered. Finally, A&P can explain all, thanks to four Japanese biologists who found a very simple and easy way to watch what happens. First though, we should explain how to breed Corydoras.

• The Breeding Set-up
• Sexing  
• Conditioning  
• The Spawning  
• The Bizarre Truth  
• Hatching and Rearing

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