The reef isn't big enough for both of us. That's the reaction of the male Clarion angelfish when he encounters other males invading his spawning territory. After aggressively chasing interlopers, he welcomes a single female to his domain. This striking fish has always been in high demand for collections, but this demand is now largely being met with captive-bred fish. However, climate change and related El Nino-Southern oscillation (ENSO) events remain a serious threat to its life on the reef