Hey Guys,
There is so much false information out there about sexing and breeding behaviour for SD's, so i thought i'd share what i learnt from first hand experience a few years ago when i had a breeding colony of SD's.
I posted this info recently in another thread to help a fellow member and thought it may help more ppl if i put it here...
To sex silver dollars, look at the anal fin... Females anal fin is straight, males anal fin has a "bump" 3/4 the way down.
(Attached below is a dodgy 2 second paint edit to show the difference between male and female anal fins)
When they're getting ready to spawn you will notice some of the following changes in the fish - 2 black blotches behind the gills(mainly in the males), black/red fin edges and overall more colourful bodies (Red/Black).
The males will chase the females, swim up next to them then wrap their anal fin under the female. Female releases around 20+ eggs, the male fertilizes them, they shake then seperate quickly scattering eggs. They will continue doing this for hours at a time until the female has released all her eggs, which can be thousands!
The eggs are clear and TINY (From memory - 1-1.5mm diameter), if you don't look hard enough you won't see them. If there are any other fish in the tank they will sometimes follow the silver dollars waiting for the eggs to be released.
I used to wait until the silver dollars are finished then vacume area's of the tank where the eggs would accumulate from water flow, chuck them in an egg tumbler and see how they go.
I've heard of people spawning SD's over marbles/egg crate/wool etc so the eggs fall between the gaps, to prevent them from being eaten. I honestly can't remember if the parents tried to eat the eggs, i have a feeling they didn't...
Feel free to post your experiences, questions etc.
Hope that helps
