Piranha as Prey

Piranha as Prey

Many piranhas fall victim to predators looking for an easy meal. Despite their fierce reputation piranhas are relatively skittish and nervous. One moment of carelessness may mean the end of your life. In the wild they are part of the diet of many predators, like jaguars, caimans, boto's (freshwater dolphins) and other, larger predatory fish, which live there in abundance.

Piranhas are even preyed upon by their own relatives, especially among the young and during the dry season. This is when the amount of food is increasingly limited and the fish are frequently trapped in increasingly small puddles. Juvenile piranha's have to face even more natural predators, and are even targeted by large insects and crustaceans.

A group of Pygocentrus piranha's lives in a state of constant fear and mutual mistrust, even when all seems calm: the animals are all capable of severely wounding or even killing each other. To survive, the fish must always know where the others are, in what their states of mind they are, and how they might act the next moment. Letting your guard down may turn out fatal.

Cannibalism amongst piranhas is not unusual during the dry period, especially among the young. And perhaps also during the mating season, when aggression levels are at their highest. By weeding out the weaker animals, piranha's have the same task as the vultures or hyena's of the savannah. They are the health police of their habitat.

Piranha Fish Aquarium

The Pygocentrus and Serrasalmus genera contain the species that most piranha owners keep. Most captive piranhas are less skittish and shy when they live in a tank with enough places to hide and dimmed lights. It makes them feel more at ease and secure, which will be reflected in their behavior. The fish will be more active, swim around more freely, and behaving in a more 'natural' way.

Pygocentrus species live in large schools in the wild and this situation is impossible to imitate in captivity. But even in a tank they will show some traits of their wild behavior, provided they are kept under proper conditions. In most cases, the alpha-animal will be the largest, most aggressive and bold specimen. It will be first at feeding sessions. It will own and guard the best spots in the tank, like the spot with the best view and the best place during feeding time, or in the current from a powerhead. Any unwilling 'servants' will be corrected instantly by aggressive behavior, chasing or even inflicting wounds.

Piranha's from the genus Serrasalmus are solitary fish, with the exception of a few species like the Gold Piranha or Gold Spilopleura Serrasalmus spilopleura, Ruby Red Piranha Serrasalmus maculatus, and Violet Line Piranha
Serrasalmus geryi. In general, they will not tolerate other fish in their tank, and are very aggressive and territorial.

Piranha Sexual differences

Determining the gender of piranhas is considered almost or all together impossible by most piranha experts. There are no visible differences between the genders, in other words piranhas are not sexually dimorphic.

The general consensus is that the only more or less foolproof method to sex piranha's is to observe them during spawning. It is true that adult female specimens tend to be thicker due to the eggs they carry. Nonetheless that is an unreliable method to tell both genders apart, as well-fed males are often just as thick.

The only known exceptions to this sexual dimorphism are possibly the Five-Cusped Piranha Pygopristis denticulate, and the Wimpel Piranha Catoprion mento. For the Wimpel Piranha, males and females are easy to tell apart.