Re: Breeding Zebra fish
#22
I thought I would update this post and my creation of a breeding process for my Zebra Danios. I ditched the polyacrylamide balls and the marbles, and instead used an inert mesh grid (approximately 5mm) intended for cooking, from a local 99p Store. Cut to size and raised above the tank floor, it provided a perfect sieve for falling eggs. I lowered the water level and provided a couple of woollen mops and the Danios were instantly obliging and within a couple of days produced hundreds of eggs, then fry.
Progress was normal, feeding infusoria and egg yolk in the usual way and doing regular water changes. The fry grew quickly but mortality has been high. I believe this to be due to poor swim bladder development. A high proportion of fry struggle to maintain buoyancy, wriggling frantically to gain an inch, then falling back to the tank floor, while others swim effortlessly, foraging for food.
A brief Google search shows the factors affecting swim bladder development are many - changes in pH, light, temperature, diet, chemical contamination and even water movement to name a few. But I suspect the main factor to be inbreeding. It might be better if I bred independent strains but I wonder where my local shops buy their stock and if it all comes from the same source. I know nothing about commercial breeding of Zebras but how many commercial breeders can there be?!
Even though mortality has been high I still have over 100 healthy fry. They are delightful to watch and are beginning to show body markings and to respond as a shoal.