Mylossoma sp. Silver Dollar

If you like the look of Pacus, but want something manageable that is pretty and schools, this might be your fish!

These arrived here as Mylossoma duriventre, which is a less commonly encountered “Silver Dollar” type of serrasalmid also known as a Silver Mylossoma, and various names including “Pacu”. Other indentifications have been placed on these fish, including Mylossoma aureum, which is very similar to M. diriventre. These fishes were exported from Colombia, which suggests they are in fact M. aureum based on the most recent research. Depending on the species, they can reach lengths of 20-25 cm (8 to 10 inches). Our current group is averaging a body diameter roughly the size of a quarter. A single fish would likely be uncomfortable, and as such, I am only selling these in group-lots at this time.

While the species ID is up in the air for me, it’s suggested that this is a whitewater species, which generally suggests a tolerance of middle-of-the-road water parameters in terms of pH and hardness. Overall, I’ve found these to be nippy amongst themselves, but heavy feeding really curbed that tendency and produced robust fish with minimal fin nips. They are omnivores and will require plant matter in their diet. These “Silver Dollars” will become very round at maturity and will make a great shoal for a very large tank. As the fish mature, their body will become even deeper. They will lose the eyespot/ocelli on the flank, and will likely develop a black spot on the middle/margin of the operculum/gill cover. They may develop striking red margins on the caudal and anal fin, and will be predominantly silver.

Here’s a quick photo from Flickr user larsjuh (CC BY 2.0) that shows a mature Mylossoma duriventre, so you have an idea what these fish will turn out like over time!