Small Scaled Pacu

Piaractus mesopotamicus 

Habitat & Distribution : Paraguay River, South America 

Diet : Seeds, nuts, crustaceans

Size: 62 cm 

Lifespan : 15 years

Description

A robust fish, with ovoid shape, flattened laterally. Its colour is dark grey to silver, with a white belly and a yellow breast. Uniquely, their teeth are flat, squared, and molar shaped like a human's, this is due to their frugivorous diet, to crush hard nuts and fruits 

Behavior

Pacu are predominantly frugivores as adults, actively feeding on falling fruit and seeds. This behavior makes them vital for forest regeneration, as they often defecate viable seeds, helping to spread plant life across the floodplain. 

Reproduction

They reproduce through external fertilization, spawning annually during the wet season when water temperatures reach around . Females scatter up to 1,000,000 adhesive eggs, which are fertilized by males and abandoned. 

Communication & Perception

Pacu communicate primarily through a combination of chemical signaling, lateral line vibrations, and acoustic signals, which are particularly important for maintaining social structure in their schools. 

Predator(s)

Large birds, caiman, larger predatory fish