Does koi fish fight with Murray cod?

It's highly unlikely that koi fish would fight with Murray cod. Here's why:

* Size Difference: Murray cod are apex predators in their environment. They are significantly larger than koi fish and can grow to over 1.5 meters long. Koi, on the other hand, are relatively small, typically reaching a maximum length of around 90cm.

* Diet: Murray cod are carnivorous and primarily feed on other fish, crustaceans, and insects. Koi are primarily herbivores and feed on plant matter and algae.

* Natural Behavior: Murray cod are ambush predators and are not known to actively seek out smaller fish like koi.

While there might be rare instances where a Murray cod could prey upon a koi, it's not a common occurrence. The size difference and dietary preferences make it highly unlikely for them to engage in a fight.

Important Note: This information assumes a natural environment. In an artificial setting, like a pond, the dynamics could be different.