Cynolebias nigripinnis (Argentine pearl with black fins)

Nigrinnis cynolebias fish is a freshwater fish belonging to the rivulidae family. It is native to the shallow waters of the hydrographic basins in eastern South America, notably Brazil, Uruguay and Argentina. Nigrinnis cynolebias fish is a small fish, generally measuring between 2.5 and 4 centimeters long. Its color varies from dark gray to black, with white spots on the body and fins. Nigrinnis cynolebias fish has an elongated and slender shape, with a rounded head and prominent eyes. Its mouth is located in the ventral position and is equipped with small conical teeth.

Nigrinnis cynolebias fish is an omnivorous fish that feeds mainly on small invertebrates, such as insect larvae, crustaceans and worms. It can also consume microscopic plants and algae. Nigrinnis cynolebias fish is generally lonely and slowly moves in water while swimming with its pectoral fins. However, it can regroup with other individuals of its species to feed or reproduce.

The Nigrinnis cynolebias fish is an oviparous fish, that is to say that it lays eggs that hatch outside the female body. The female can lay up to 100 eggs at a time, which it deposits on solid surfaces or on submerged plants. The eggs hatch about a week later and the fry develop quickly. Nigripinnis cynolebias fish reached its sexual maturity at the age of two months and can live up to two years in its natural habitat.

Nigrinnis cynolebias fish is a common fish in its natural habitat, although it is threatened by the destruction of its habitat by humans. Nigrinnis cynolebias fish is also often used as aquarium fish, where it is appreciated for its color and small size. Due to its popularity in aquarophilia, Nigrinnis cynolebias fish is often high in captivity and is therefore not threatened with extinction.