This is a little trickier than you might think. Do you QT your fish? Are you attached to the male Clownfish? From the moment that the female is removed or dies, you have as little as 9 days before the male begins to turn into a female. When that happens, if you add another clown that is female, one will kill the other. So you have a few options.
1. You can wait a few months for your current male to turn into a female and then purchase a male clownfish.
2. You can purchase a female and try and get them to pair up, but this has to be done before the male begins to turn into a female.
3. You can buy another male and allow them to figure out which is dominant, at which time the dominant clowfish will become the female.
4. You can sell / give away your male and purchase an already bonded pair.
5. Do nothing and end up with one female clownfish.
I lost my female to an unexplained death and went through this a few months ago. In the end, my clownfish became best friends with my Bristletooth tang and now they follow each other around all day. Clyde (my clownfish) thinks he is a Tang and mimics my Tangs constant picking at the glass and rocks. He has also become a fan of the seaweed sheets I put in the tank recently. It's actually very amusing watching a clownfish try and eat algae off the glass.
I keep saying 'He', but Clyde is now a girl.
Anyway, that's just my experience. Good luck!
