Re: think my Oto's have been breeding!
#4
Both are egg layers and don't become pregnant. The females swell up a bit when full of eggs and then spawning behaviour varies from species to species.
Female Otos are broader than males to start with though so it can be hard to tell if they are egg-laden.Their breeding behaviour is very similar to that of Corys - 2 or more males chase a female usually up and down the tank glass. A male and female then assume a "T" position as the eggs are laid and fertilised and the female catches them in her pectoral fins and places them in a pre-cleaned spot in the tank, often on the underside of a leaf. For the young to survive after hatching they need huge amounts of algae and green water to feed on.
With Cherry Barbs, when the female is ready to release eggs they are scattered generally about the tank and the males follow on and fertilise them. The fry are slightly larger than Oto fry when first hatched and need infusoria for the first few days after which any small pieces of food will sustain them. They are transparent at first, and when they gain colour, the black appears before the red, with fins staying transparent for some time (females have lighter coloured fins than males even when adult).