Serrasalmus rhombeus are commonly called black rhoms, redeye piranhas or black piranhas in the aquarium hobby. Out of all the piranha species, they are the pnes that grow the larges. Some specimens have reached 55 cm.

BELOW: Video of a adult Serrasalmus rhombeus in an aquarium.

BELOW: Image of a adult Serrasalmus rhombeus.
Picture taken 01/17/2011 with a Sony A55 (flash off) Lens: Sony Macro 100mm. f2.8 1/80 ISO 200

BELOW:  A large Serrasalmus rhombeus. The coin on it is a little over an inch in diameter (2.8 cm.)
Picture taken 06/19/2008 with a Sony DSC-H1 (flash on) f4 1/100 ISO 64

BELOW:  A local buys a couple of Serrasalmus rhombeus from the fishermen. The Black Rhom piranha is eaten regularly in this area.
Picture taken 06/19/2008 with a Sony DSC-H1 (flash on) f4 1/200 ISO 64

BELOW:  We found a yellow eyed, and yellow bodied Serrasalmus rhombeus. As we have visited the river in different seasons and they still maintain the yellow coloration, it seems not to be a reproductive color pattern; it seems to be caused by the water composition or parameters. This specimen was caught by George Fear.
Picture taken 05/17/2006 with a Sony DSC-H1 (flash off) f4 1/500 ISO 64

BELOW:  Image of a Serrasalmus rhombeus that has been through the process of diaphanisation (clearing and
staining).
Picture taken 05/13/2010 with a Sony DSC-H50 (flash off) f4 1/160 ISO 100