The disc-shaped body of bleeding heart tetras is strongly compressed and relatively deep in males and females. Male body length ranges from 29.1 to 60.6 mm (n=6), female body length ranges from 29.0 to 53.3 mm (n=7). Males and females also differ somewhat in color and fin characteristics.
Dorsally, bleeding heart tetras are a delicate shade of grey-green to brown but with a light red bloom. A reddish silver color shades the bottom half of the body while the throat and belly region are orange. They bear a vivid red mark resembling a heart behind their gill cover, giving them their common name. Males are known for having more color and elaborate fins. Dorsal fins of males are sickle-shaped, longer, and more pointed whereas dorsal fins of females are shorter with a rounded tip. Dorsal fins in both males and females are black, pink, purple, and white. Males have a longer anal fin that is white in color. The anal fins of females are shorter and not as white. Other fins are pink to grey in color. As bleeding heart tetras age they develop a more pronounced arch to their spine.
Range length: 29 to 60.6 mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful