''Copella'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of freshwater fish belonging to the family

Lebiasinidae The Lebiasinidae are a family (biology), family of freshwater fishes found in Costa Rica, Panama, and South America. They are usually small and are known as ornamental fishes in Aquarium, aquaria, including popular fishes such as the various penc ...

, native to South America, known colloquially to

aquarist An aquarist is a person who manages aquariums, either professionally or as a hobby. They typically care for aquatic animals, including fish and marine invertebrates. Some may care for aquatic mammals. Aquarists often work at public aquariums. They ...

s as splashing tetras or splash tetras, because of the unique reproductive method of the best-known representative of the genus, ''

Copella arnoldi ''Copella arnoldi'', commonly known as the splash tetra or the splashing tetra, is a species of tropical freshwater fish belonging to the family Lebiasinidae. It is native to South America, and has been introduced to the island of Trinidad. The ...

''. They are not as closely related to the

tetra Tetra is the common name of many small freshwater characiform fishes. Tetras come from Africa, Central America, and South America, belonging to the biological families Characidae, Alestidae (the "African tetras"), Lepidarchidae, Lebiasi ...

s proper in the

Characidae Characidae, the characids, is a family of freshwater subtropical and tropical fish belonging to the order Characiformes. They are found throughout much of Central and South America, including such major waterways as the Amazon and Orinoco Riv ...

as initially believed. ''Copella'' species are found in assorted slow-moving tributaries in the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

and

The Guianas The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British, Dutch, and French Guiana respectiv ...

Description

These fish are elongated in shape, with scales marked in such a way as to make visual differentiation of individual scales easy by simple naked-eye observation. The pectoral fins are positioned immediately behind the operculum or gill cover, while the pelvic fins are further back along the body, about midway between the head and the caudal peduncle. The dorsal fin is positioned above and slightly behind the pelvic fins, and midway between the pelvic fins and the tail fin is the anal fin. The tail fin is forked in shape. Males usually possess more elongated and ornate unpaired fins than females. In the case of ''C. arnoldi'', the tail fin of the male is somewhat asymmetrical, the upper lobe being larger than the lower lobe, and this modification of the more usual symmetrical tail fin shape (tail fin symmetry is a characteristic of the majority of fishes belonging to the Actinopterygii) is linked to the reproductive activity of the species.

Species

Originally, numerous species belonging to this genus were placed in the genus '' Copeina''. Taxonomic revisions taking place in 1994 and afterwards have moved all of these fishes into ''Copella''. The currently recognized species in this genus are: * ''

'' ( Regan, 1912) (splash tetra) * '' Copella carsevennensis'' (Regan, 1912) * '' Copella compta'' ( G. S. Myers, 1927) * '' Copella eigenmanni'' (Regan, 1912) * '' Copella meinkeni'' Zarske &

Géry Géry () is a commune in the Meuse department in Grand Est in north-eastern France. See also *Communes of the Meuse department The following is a list of the 499 Communes of France, communes of the Meuse (department), Meuse Departments of ...

, 2006 * '' Copella metae'' ( C. H. Eigenmann, 1914) * '' Copella nattereri'' (

Steindachner Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner descri ...

, 1876) (spotted tetra) * '' Copella nigrofasciata'' ( Meinken, 1952) * '' Copella vilmae''

, 1963 (rainbow copella)

Unusual breeding behaviour in ''C. arnoldi''

Though the majority of fishes of this genus spawn in a conventional fashion among fine-leaved aquatic plants, ''C. arnoldi'' (and any undescribed relatives) is unique among fishes in that it lays its eggs on plants out of water. The male displays to passing females beneath overhanging vegetation growing beside its native waters, and when a receptive female accepts the invitation to spawn, she positions herself directly alongside the male, and the pair leaps out of the water together, attaching themselves by fin suction to the underside of a leaf. The pair then produces and fertilises 6-8 eggs, before falling back into the water. This procedure is repeated until as many as 200 eggs are attached to the leaf. Once the egg mass is complete, the male positions himself among fine-leaved vegetation, watching the egg mass, and intermittently emerges from cover to splash the eggs with water using his asymmetrical tail fin to keep the eggs moist. Once the eggs hatch, the fry fall into the water from the leaf and swim for cover. As a consequence of this remarkable breeding behaviour, which is unique amongst the world's fishes, the members of the entire genus have come to be known colloquially as splashing tetras, though strictly speaking the only fish that deserves this epithet is ''C. arnoldi''.

References

External links

Splashing Tetra Fact Sheet
{{Taxonbar, from=Q868992 Lebiasinidae Tetras Taxa named by George S. Myers Fish of South America