Aggressive Clowns???

So, my 12 gal tank has had several generations of fish. However, I have two "Nemo" Clowns that have been with me from the beginning. When we got them, we also got a tang, a goby and a six-lined wrasse. Through some very interesting history, the other fish have all gone, been replaced, and then died of one reason or the other (like the killer purple lobster that joined us by accident), the wrasse being the last to die. The two clowns have remained. I recently bought a 4-lined wrasse to add back into the tank. He wasn't very big. Total, his length brought the tank up to 4"-5" of fish. The wrasse didn't last 24 hours. Is it possible that my clowns are killing new fish? The bigger clown is slightly aggressive toward the smaller one, but I've never seen them go after another species. Any thoughts?

Wondering in So. Cal.

 

It's possible, but I would check your salinity, ammonia, nitrite, and nitrates first.
your tank is way to small to support a tang.

the aggression between the two clowns is normal, the big one is the female.

 

Clowns are like dalmation dogs, cool looking but dumb as rocks! They will also be more tolerant of tank params being off.