This specific term designates a variant of the Metynnis hypsauchen, more commonly known as the Silver Dollar fish, characterized by distinct blue markings around the hook-like portion of its anal fin. These markings often intensify with age and maturity. It’s a freshwater fish popular in the aquarium hobby due to its generally peaceful nature and shimmering, silver-colored body. For instance, a mature specimen might exhibit a prominent sapphire hue bordering the fin’s leading edge, setting it apart from its counterparts.
The recognition of this characteristic is vital for aquarists seeking to differentiate between standard Silver Dollars and this unique variation. This distinguishing trait can influence purchasing decisions and aquarium setup considerations, particularly concerning tank size and suitable tankmates. Historically, identification keys for Metynnis hypsauchen primarily focused on body shape and general coloration; however, the emphasis on this specific fin marking allows for more refined species identification and a better understanding of morphological variations within the species.
