Canary Blenny Could Kill Firefish?



Hi everyone, I wanted to know something. Can a canary blenny kill firefish gobies or purple firefish gobies? I wanted to know because I bought one and after like a week, my three firefish gobies and my purple gobie died, I don't know why it did. Can it be that the canary blenny bite them and kill them. Because I just notice right now that it has some stuff on the mouth just like a snake, the things that have poison. And one of them I think is broke because I don't see it and it has red on it. I notice it because I put live brine shrimp and he opens his mouth and you could see that thing like what the snake has, he bites the live shrimp and throws it and eats it back. Another thing, if it bites it and throws it back, and my clown eats it, would the clown die?