Zebrafish Sex

I learned about the birds & the bees (and the zebrafish) at work yesterday.

The "fish house"--the room in our research building where the zebrafish is stored--is impressively organized and packed with small aquariums containing a few to several swimming zebrafish. Although it's a spacious room, it pales in comparison with the amount of space (and generally unpleasant smell) of mouse facilities, another common organism for research.

I was pretty surprised at how efficient zebrafish mating is. In the afternoon, one male and two females are placed in the same tank--but they are separated by a "mating divider", which is simply a piece of plastic. They have a chance to meet and get to know one another. Then, the next morning, after a good night's sleep (with the lights out), the divider is removed and the fish are able to go at it. Usually within 10 minutes, they will have successfully mated, which I find amazing. The female will spew up to 300 eggs onto the bottom of the aquarium, where they can be collected by passing through a simple strainer. Each one of these eggs has the potential to develop into a happy adult zebrafish.