Predatory fish are awesome in their own right, but are obviously not well-suited for a community tank setup. Here are several distinguishing features that predatory have. None of these features alone would identify a predator, but a combination of them is a worrying sign 😉
Size: Fish that are two or three times bigger than other tank mates might view others as food.
Torpedo body: Long arrow-shaped bodies are designed for sudden bursts of speed to catch prey. Pike and gars are good examples.
Teeth: This may sound obvious, but fish with long obvious teeth designed for grabbing and holding are bound to eat anything that fits in its mouth.
Whiskers: Species of catfish have long elongated whiskers for detecting prey in dark deep waters. Expect them to munch on any type of fish that gets detected with these whiskers.
Camouflage and hiding: Although some peaceful species use camouflage to avoid predation, some use it to hunt! Fish that burry themselves or blend in well with leaves prepare themselves for a surprising attack.
Eye position: Fish with forward facing eyes give them overlapping vision and in-depth perception for ambushing prey.
Pike (Esox lucius)