Copella (genus)
Encyclopedia
Copella is a genus
of freshwater fish belonging to the Family Lebiasinidae
, native to South America, known colloquially to aquarists as Splashing Tetras or Splash Tetras, because of the unique reproductive method of the best-known representative of the genus, Copella arnoldi. They are not as closely related to the tetra
s proper in the Characidae
as initially believed.
Copella species are found in assorted slow-moving feeder tributaries of the Amazon and other large South American rivers, particularly in the north of the continent in countries such as Guyana and Venezuela.
or gill cover, while the pelvic fins are further back along the body, approximately 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 elongate and ornate unpaired fins than females. In the case of Copella 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.
Nine species
were accepted as valid members of the genus Copella as of 2007. In addition, there appear to be several undescribed species or subspecies
:
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 Copella arnoldi itself.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of freshwater fish belonging to the Family Lebiasinidae
Lebiasinidae
The Lebiasinidae , are a family of freshwater fishes found in Costa Rica, Panama, and South America. They are usually small and are known as ornamental fishes in aquaria, including popular fishes such as the pencil fish and splashing tetra.Lebiasinids are small, cylindrical fish, ranging from to ...
, native to South America, known colloquially to aquarists as Splashing Tetras or Splash Tetras, because of the unique reproductive method of the best-known representative of the genus, Copella arnoldi. They are not as closely related to the tetra
Tetra
thumb|right|250px|Pristella tetra — [[Pristella maxillaris]].thumb|right|250px|Golden Pristella tetra, a [[morph |morph]] of [[Pristella maxillaris]].thumb|right|250px|[[Silvertip tetra]] — Hasemania nana....
s proper in the Characidae
Characidae
The Characidae, characids or characins are a family of freshwater subtropical and tropical fish, belonging to the order Characiformes. The name "characins" is the historical one, but scientists today tend to prefer "characids" to reflect their status as a by and large monophyletic group at family...
as initially believed.
Copella species are found in assorted slow-moving feeder tributaries of the Amazon and other large South American rivers, particularly in the north of the continent in countries such as Guyana and Venezuela.
Description
These fish are elongate in shape, with scales that are 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 operculumOperculum (fish)
The operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body....
or gill cover, while the pelvic fins are further back along the body, approximately 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 elongate and ornate unpaired fins than females. In the case of Copella 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.Nine species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
were accepted as valid members of the genus Copella as of 2007. In addition, there appear to be several undescribed species or subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
:
- Copella arnoldi
- Copella carsevennensis
- Copella compta
- Copella eigenmanni
- Copella meinkeni
- Copella metae
- Copella nattereri - includes C. callolepis
- Copella nigrofasciata - doubtfully distinct from C. nattereri
- Copella vilmae
- Copella cf. meinkeni "Pinter 1993"
- Copella cf. arnoldi "Upper Maroni"
Unusual breeding behaviour in Copella arnoldi
Though the majority of fishes of this genus spawn in a conventional fashion among fine-leaved aquatic plants, Copella arnoldi (and any undescribed relatives) is unique among fishes in that it lays its eggs 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 leap out of the water together, attaching themselves by fin suction to the underside of a leaf. The pair then produce and fertilise approximately 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 in order 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 Copella arnoldi itself.