Wednesday, August 11, 2010

Where Do Babies Come From?

About a month ago we were admiring our school of Shiner Perch when we noticed that about seven of them were looking a little larger in the mid-region. Pigged –out on krill? Doubtful. The more likely possibility was that they were pregnant!

Shiner Perch have a complex mating system where the males perform a courtship dance for attractive females. If their moves are good enough the female might let the males mate with them. Sound familiar? Five to six months later anywhere from three to 40 babies are born.

After a few weeks our Shiners looked about ready to explode with their little babies. In preparation for the mass birthing, we relocated any potential baby eaters such as black rockfish, predators capable of turning the miracle of life into an all you can eat buffet!

On August 10th the aquarium crew arrived to the work in the morning to find that our Shiner Perch had collectively given birth to around 40 babies, and a couple more were still birthing little ones; tail first…ouch!

The babies, 1 ¼” miniature version of their parents, are born so well developed that they practically swim out of their mothers. The males are also born reproductively mature with females maturing only a few weeks later.

This isn’t the first time this season that some of our fish have given birth. Last month our Tiger Rockfish gave birth only hours before she was supposed to go the rockfish breeding facility at the Vancouver Aquarium. Spawning is almost a weekly event in the aquarium with various species releasing mass amounts of sperm and eggs into the surrounding water. Visit the aquarium for answers about where babies come from!

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