Interesting... I hope this is not the case. But I bought the 3 fish from 2 different vendors. Can you say which country your fish came from?
The issue they are describing is the collection of fish in some regions with cyanide. That does not apply in this case as cyanide causes chronic health issues that sometimes result in death, where this is a sudden onset (acute) issue from which the fish recovers...two very different scenarios.
If you are interested in sourcing fish from better regions, I recently posted this article here:
Sourcing Marine Fishes and Invertebrates
Sourcing Marine Fishes and Invertebrates Experienced aquarists are aware that fishes from different regions of the world can have different levels of sustainability when acquired for their aquariums. The reasons for these differences may include...
www.reef2reef.com
Jay