TROPICAL
I was reading recently that blind cave fish are born with eyes, and it made me think that perhaps they'd make a really interesting breeding project. Do you have any tips on how to go about this in terms of tank set-up and rearing the fry please?
JUDITH EDWARDS
NEALE SAYS: Yes, oddly enough, the fry of these fish are born with eyes, but they soon degenerate, resulting in the blind fish we are familiar with.
As it happens, the blind cave tetra is actually quite a simple fish to breed. Like most tetras, it’s an egg-scatterer, and all it really takes is putting a well-fed and sexually mature pair in a tank and letting nature takes it course. But like so many other egg-scatterers, the parents are quite likely to eat the eggs given the chance, so a mesh or a layer of glass marbles at the bottom of the tank is useful to create a barrier of some sort. Alternatively, you can use bushy plants like Java moss, and the simply remove the eggs as quickly as you can. Either way, females will produce hundreds of eggs at a time, and when ‘ripe’ and ready to spawn will look distinctly plump.
Water chemistry isn’t a critical factor, though slightly alkaline water is optimal, and not too warm either, somewhere around 20°C being ideal. Lighting, of course, isn’t necessary.
After hatching, the fry will be reliant on their remaining yolk reserves for a couple of days, but after that will need infusoria. There are various ways to raise these, but all boil down to essentially creating an indoor ‘pond’ with a bruised lettuce or similar within a glass jar of water taken from the aquarium and waiting for algae and other microscopic organisms to bloom therein. Very quickly, the fry will graduate onto brine shrimp nauplii, and being fa
