What is my mandrian doing?

I introduced a female into my 90 gallon tank over the weekend. I got her pretty cheap because she was being bullied in a friends tank.



2 days after adding her she found the male and they were swimming together until later that night the male started doing this which looks like he was sucking her blood like a vampire. Why is this?? What is this??



http://ift.tt/1NZ9K5J



I couldnt figure out how to embed a video from photobucket any mod that wants to tell me the code string to do that i will fix my post.