The silver dollar is known to be a relatively peaceful species of tropical fish, but they are also known to have an aggressively dominant nature particularly towards smaller fish. These rounded fish are thought to be closely related to the infamous piranha, also found in the rivers of South America, and also not as ferocious, the silver dollar definitely shares some of the piranha's bullying instinct.
Silver dollar are generally quite sociable find, spending their lives amongst the weeds in the well-vegetated parts of the river where there is a good supply of food and protection from passing predators. Silver dollar gather together in groups known as shoals. which are able to work together to catch larger prey or to try and intimate hungry predators.
Although omnivorous animals, the silver dollar has a mainly vegetarian diet primarily eating grasses and other aquatic plants in the surrounding water. In the wild, silver dollar also supplement their diet with small invertebrates including insects, worms and spiders.
Despite their naturally aggressive nature, the small size of the silver dollar coupled with it's glimmering scales means that these fish are preyed upon by numerous species within their natural environment. Birds, large fish and reptiles are the most common predators of the silver dollar in South America.
The silver dollar is a peaceful schooling species that spends most of its time in the mid- to upper-level of the water and has a maximum lifespan that can be more than 10 years. The female adult silver dollar will spawn around 2,000 eggs. They tend to breed most commonly in soft, warm water in low light.
Silver dollar are one of the most popular tropical fish to be kept in the globally found fish tanks, however, it is advisable not to keep silver dollar with smaller fish. They are said to live quite happily though in tanks that contain larger fish species such as oscars and catfish.