Introducing second clown? Or another fish?

[Masoch]

Hi folks,

 

One of my recently mated pair of clowns (probably Clark, maybe Sebae -- but doesn't look quite like either and sold as perc) decided that life in the aquarium wasn't worth living ... and took a header out of her home. Which leaves one very lonely, male / juvenile clown in my tank.

 

My question is ... can I add another, smaller Clark? My remaining Clark is still relatively small at 2 inches (smaller than my female when I picked them up together a few weeks ago, but larger than he originally was), so is there a chance that he could become the female of a mated pair? I've poked around the web and can't quite find anything on topic. I could add a larger clown, but that seems like a crapshoot.

 

I've also thought about other fish, but chromis in general seem to have a taste for peppermint shrimp (I have 2), and I'm not sure a small goby could put up with an established clown and an established royal gramma. Otherwise, I'm pretty much stumped about what else I could add without upsetting the delicate balance in my 20 gallon.

 

Thanks for any advice!