In my opinion, killing anything is not ethical. this goes against any rights even though a lion fish is not human
The answer that sounds the best is (Any change in gravity sends a message through space)
The three observations that could help an individual in distinguising whether the organism is a fish or not is that it should live under water as fish can't survive without water, another thing is that it should laid eggs when it comes to giving birth because when it does not lay eggs but produces a living organism normally without an egg, it is considered to be a mammal and lastly, the appearance it possess such as having gils or fins.
They would he a heterozygous, a hybrid, organism.