Corydoras

Corydoras is a genus of freshwater catfish in the family Callichthyidae and subfamily Corydoradinae. The species usually have more restricted areas of endemism than other callichthyids, but the area of distribution of the entire genus almost equals the area of distribution of the family, except for Panama where Corydoras is not present.[1] Corydoras species are distributed in South America where found east of the Andes to the Atlantic coast, from Trinidad to the Río de la Plata drainage in northern Argentina.[2] Species assigned to Corydoras display a broad diversity of body shapes and coloration.[3] Corydoras are small fish, ranging from 2.5 to 12 cm (1.0 to 4.7 in) in SL.[2]

Corydoras
Temporal range: 58.5–0 Ma
Late Paleocene - Recent
Corydoras melanotaenia
Corydoras melanotaenia
Corydoras Sterbai
Corydoras sterbai
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Callichthyidae
Tribe: Corydoradini
Hoedeman, 1952
Genus: Corydoras
Lacépède, 1803
Type species
Corydoras geoffroy
Lacépède, 1803
Synonyms
  • Brochis Cope, 1871
  • Chaenothorax Cope, 1878
  • Cordorinus Rafinesque, 1815
  • Gastrodermus Cope, 1878
  • Hoplisoma Swainson, 1838
  • Microcorydoras Myers, 1953
  • Osteogaster Cope, 1894

Taxonomy

The name Corydoras is derived from the Greek kory (helmet) and doras (skin).[4] Corydoras is by far the largest genus of Neotropical fishes with more than 160 species.[4] It is the sole genus in the tribe Corydoradini.[5] C. difluviatilis is recognized as the basalmost species of Corydoradini, exhibiting several plesiomorphic features compared to the other species of Corydoras.[5][3] The type species for this genus is Corydoras geoffroy.[4] Several hundred species are not yet classified, but kept by aquarists. These species are given 'C-numbers', originally devised by Hans-Georg Evers for the German fishkeeping magazine DATZ in 1993. In 2006, 153 C-numbers had been assigned, of which 32 had been assigned appropriate scientific names.[6]

The species C. barbatus, C. macropterus and C. prionotos have been reclassified into the genus Scleromystax.[5] Brochis had been differentiated from Corydoras due to the higher number of dorsal fin rays; however, Brochis has recently been suggested to be a synonym of Corydoras.[5] This is contested and has not been universally accepted. The sixray corydoras belongs in Aspidoras.[7]

Ecology

Corydoras are generally found in smaller-sized streams, along the margins of larger rivers, in marshes, and in ponds.[2] They are native to slow-moving and almost still (but seldom stagnant) streams and small rivers of South America, where the water is shallow and very clear. Most species are bottom-dwellers, foraging in sand, gravel or detritus.[2] The banks and sides of the streams are covered with a dense growth of plants and this is where the corys are found. They inhabit a wide variety of water types but tend toward soft, neutral to slightly acidic or slightly alkaline pH and 5-10 degrees of hardness. They can tolerate only a small amount of salt (some species tolerate none at all) and do not inhabit environments with tidal influences. They are often seen in shoals.[2] Most species prefer being in groups and many species are found in schools or aggregations of hundreds or even thousands of individuals, usually of a single species, but occasionally with other species mixed in. Unlike most catfishes, which are nocturnal, these species are active during the daytime.[2]

Their main food is bottom-dwelling insects and insect larvae and various worms, as well as some vegetable matter. Although no corys are piscivorous, they will eat flesh from dead fishes. Their feeding method is to search the bottom with their sensory barbels and suck up food items with their mouth, often burying their snout up to their eyes.

In several species of Corydoras, it has been observed that the fishes, after initial evasive reaction to threat, lie still; this is suggested to be a form of cryptic behavior. However, it is also argued that most species do not have cryptic coloration nor freezing behavior and continue to exist.[2] A few species of Otocinclus: (O. affinis, O. flexilis, O. mimulus and O. xakriaba) are considered to be Batesian mimics of certain Corydoras species (C. diphyes, C. garbei, C. nattereri and C. paleatus, respectively). These species have bony plates of armor and strong spines as defenses, making them less palatable; by mimicking these species in size and coloration, Otocinclus avoid predation.[2]

A unique form of insemination has been described in Corydoras aeneus. When these fish reproduce, the male will present his abdomen to the female. The female will attach her mouth to the male's genital opening, creating the well-known "T-position" many Corydoras exhibit during courtship. The female will then drink the sperm. The sperm rapidly moves through her intestines and is discharged together with her eggs into a pouch formed by her pelvic fins. The female can then swim away and deposit the pouch somewhere else alone. Because the T-position is exhibited in other species than just C. aeneus, it is likely that this behavior is common in the genus.[8]

In the aquarium

The genus is well known among aquarists for its many ornamental species.[9] They are well suited to tropical freshwater community aquariums, as they get along well with other species and are not at all aggressive. Corydoras are quite timid and are recommended to be kept in shoals of three upwards. Corys are mostly bottom feeders, so they should be offered sinking pellets as well as supplements of live and frozen foods. If flake foods are used, care should be taken to prevent all food from being eaten by faster moving fish at the higher levels of the tank.

Most corys prefer soft, acidic water. They can, however, tolerate a wide range of water conditions, including temperatures that are cooler than tropical. They do not do well in fish tanks with high nitrate levels. This ion leads to the infection of the barbels, which will shorten and become useless. The barbels may also be affected by constant contact with a sharp substrate. They are more likely to thrive if there is an open area of substrate on the bottom of the tank where they can obtain submerged food. It is a myth that salt cannot be used on this species of fish as a means of parasite medication. Salt can be added to the water of the Corydoras catfish in order to rid the fish of ich. These fish are fairly easy to keep, being peaceful, hardy, active and entertaining. Occasionally they will dart to the surface, sticking their snout above the water for an instant to take a "breath" of air. This behavior is perfectly normal and is not an indication that anything is wrong with the fish. However, if this is done in excess, it can indicate poor water conditions.

Where investigated Corydoras sp. have been shown to be diurnal and crepuscular rather than nocturnal and activity can even peak at twilight.[10] Corydoras are very good choices for a community aquarium and are widely kept throughout the world. Their longevity in the aquarium is noteworthy; C. aeneus is said to have lived 27 years in captivity and 20 years is not too uncommon.

Species

There are currently 161 recognized species in this genus:

See also

References

  1. ^ Reis, R.E. (1996). "Corydoras". Tree of Life Web Project.CS1 maint: Uses authors parameter (link)
  2. ^ a b c d e f g h Axenrot, T.E. & Kullander, S.O. (2003): Corydoras diphyes (Siluriformes: Callichthyidae) and Otocinclus mimulus (Siluriformes: Loricariidae), two new species of catfishes from Paraguay, a case of mimetic association. Archived 2009-02-05 at the Wayback Machine Ichthyological Exploration of Freshwaters, 14 (3): 249–272.
  3. ^ a b Britto, M.R. & Castro, R.M.C. (2002): New Corydoradine Catfish (Siluriformes: Callichthyidae) from the Upper Paraná and São Francisco: The Sister Group of Brochis and Most of Corydoras Species. Copeia, 2002 (4):1006-1015.
  4. ^ a b c Froese, Rainer, and Daniel Pauly, eds. (2016). Species of Corydoras in FishBase. January 2016 version.
  5. ^ a b c d Britto, M.R. (2003): Phylogeny of the subfamily Corydoradinae Hoedeman, 1952 (Siluriformes: Callichthyidae), with a definition of its genera. Archived September 28, 2007, at the Wayback Machine Proceedings of the Academy of Natural Sciences of Philadelphia, 153 (1): 119-154.
  6. ^ Evers, H.-G. (2006). "A system called "C-Numbers"". Archived from the original on 2006-06-19.CS1 maint: Uses authors parameter (link)
  7. ^ Froese, Rainer and Pauly, Daniel, eds. (2016). "Aspidoras pauciradiatus" in FishBase. January 2016 version.
  8. ^ Kohda, M., Tanimura, M., Kikue-Nakamura, M. & Yamagishi, S. (1995): Sperm drinking by female catfishes: a novel mode of insemination. Environmental Biology of Fishes, 42 (1): 1–6.
  9. ^ Huysentruyt, F. & Adriaens, D. (2005): Descriptive osteology of Corydoras aeneus (Siluriformes: Callichthyidae). Cybium, 29 (3): 261–273.
  10. ^ Paxton, C.G.M. (1997): Shoaling and activity levels in Corydoras. Journal of Fish Biology, 51 (3): 496–502.
  11. ^ Espíndola, V.C., Spencer, M.R.S., Rocha, L.R. & Britto, M.R. (2014): A new species of Corydoras Lacépède (Siluriformes: Callichtyidae) from the rio Tapajós basin and its phylogenetic implications. Papéis Avulsos de Zoologia, 54 (3): 25-32.
  12. ^ a b c Tencatt, L.F.C. & Britto, M.R. (2016): A new Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Araguaia basin, Brazil, with comments about Corydoras araguaiaensis Sands, 1990. Neotropical Ichthyology, 14 (1): e150062.
  13. ^ a b Tencatt, L.F.C. & Ohara, W.M. (2016): Two new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Madeira basin, Brazil. Neotropical Ichthyology, 14 (1): e150063.
  14. ^ a b Tencatt, L.F.C. & Ohara, W.M. (2016): A new long-snouted species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Madeira basin. Zootaxa, 4144 (3): 430–442.
  15. ^ Ottoni, F.P., Barbosa, M.A. & Katz, A.M. (2016): A new Corydoras from floodplain swamps of the São Francisco river basin, northeastern Brazil. Spixiana, 39 (1): 131-140.
  16. ^ a b Tencatt, L.F.C., Britto, M.R.d. & Pavanelli, C.S. (2016): Revisionary study of the armored catfish Corydoras paleatus (Jenyns, 1842) (Siluriformes: Callichthyidae) over 180 years after its discovery by Darwin, with description of a new species. Neotropical Ichthyology, 14 (1): e150089.
  17. ^ Tencatt, L.F.C., Britto, M.R. & Pavanelli, C.S. (2014): A new long-finned Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the lower rio Paraná basin, Brazil. Neotropical Ichthyology, 12 (1): 71-79.
  18. ^ Tencatt, L.F.C. & Pavanelli, C.S. (2015): Redescription of Corydoras guapore Knaack, 1961 (Siluriformes: Callichthyidae), a midwater Corydoradinae species from the rio Guaporé basin. Neotropical Ichthyology, 13 (2): 287–296.
  19. ^ Ohara, W.M., Tencatt, L.F.C. & Britto, M.R. (2016): Wrapped in flames: Corydoras hephaestus, a new remarkably colored species from the Rio Madeira basin (Teleostei: Callichthyidae). Zootaxa, 4170 (3): 539–552.
  20. ^ Tencatt, L.F.C. & Evers, H.-G. (2016): A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the río Madre de Dios basin, Peru. Neotropical Ichthyology, 14 (1): e150019.
  21. ^ Tencatt, L.F.C., Britto, M.R. & Pavanelli, C.S. (2014): A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the upper rio Paraná basin, Brazil. Neotropical Ichthyology, 12 (1): 89–96.
  22. ^ Tencatt, L.F.C., Vera-Alcaraz, H.S., Britto, M.R. & Pavanelli, C.S. (2013): A new Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio São Francisco basin, Brazil. Neotropical Ichthyology, 11 (2): 257–264.
Banded corydoras

The banded corydoras or bearded catfish (Scleromystax barbatus) is a subtropical freshwater fish belonging to the Corydoradinae sub-family of the Callichthyidae family. It originates in coastal drainages in South America from Rio de Janeiro to Santa Catarina, Brazil.

Blue corydoras

The blue corydoras or Natterer's catfish (Corydoras nattereri) is a tropical freshwater fish belonging to the Corydoradinae sub-family of the Callichthyidae family. It originates in coastal rivers in South America, and is found in the Brazil from Espírito Santo to Paraná. It is named for Johann Natterer, its discoverer.

The fish has clear fins with no pattern. The ventrals are light, opaque yellow. Highlights seen about the gill plates are green. The belly is yellowish. It has a pronounced dark stripe along the length of the body. General color of the body is light, tending towards yellow. Its eyes are gold. It will grow in length up to 5.4 centimetres (2.1 inches).

It lives in a tropical climate in water with a 6.0 – 8.0 pH, a water hardness of 2 – 25 dGH, and a temperature range of 20–23 °C (68–73 °F). It feeds on worms, benthic crustaceans, insects, and plant matter. It lays eggs in dense vegetation and adults do not guard the eggs.

The blue corydoras is of commercial importance in the aquarium trade industry.

Bluespotted corydoras

The bluespotted corydoras, blacksail corydoras, blackspotted corydoras, dotted corydoras, Guiana cat or Guiana corydoras (Corydoras melanistius) is a tropical freshwater fish belonging to the Corydoradinae sub-family of the family Callichthyidae. It originates in inland waters in South America, and is found in the coastal rivers of French Guiana, Guyana, and Suriname. The specific epithet melanistius means black sail, referring to the dorsal fin.

The fish will grow in length up to 5.1 centimetres (2.0 inches). It lives in a tropical climate in water with a 6.0 - 8.0 pH, a water hardness of 2 - 25 dGH, and a temperature range of 22–26 °C (72–79 °F). It feeds on worms, benthic crustaceans, insects, and plant matter. It lays eggs in dense vegetation and adults do not guard the eggs. The female holds 2-4 eggs between her pelvic fins, where the male fertilizes them for about 30 seconds. Only then does the female swim to a suitable spot, where she attaches the very sticky eggs. The pair repeats this process until about 100 eggs have been fertilized and attached.

The bluespotted corydoras is of commercial importance in the aquarium trade industry.

Bronze corydoras

The bronze corydoras (Corydoras aeneus), green corydoras, bronze catfish, lightspot corydoras or wavy catfish is a tropical freshwater fish in the "armored catfish" family, Callichthyidae, often kept in captivity by fish keepers. It is widely distributed in South America on the eastern side of the Andes, from Colombia and Trinidad to the Río de la Plata basin. It was originally described as Hoplosoma aeneum by Theodore Gill in 1858 and has also been referred to as Callichthys aeneus.

Callichthyidae

Callichthyidae is a family of catfishes (order Siluriformes), called armored catfishes due to the two rows of bony plates (or scutes) along the lengths of their bodies. It contains some of the most popular freshwater aquarium fish, such as many species in the genus Corydoras.

Corydoras julii

Corydoras julii (also known as the julii cory or leopard catfish) is a small freshwater catfish native to eastern Brazil. It is a popular aquarium fish.

Corydoras paleatus

Corydoras paleatus is a species of catfish (order Siluriformes) of the family Callichthyidae. Its common names include blue leopard corydoras, mottled corydoras and peppered catfish. It originates from the lower Paraná River basin and coastal rivers in Uruguay and Brazil.

Corydoras panda

Corydoras panda is a species of catfish belonging to the genus Corydoras, of the family Callichthyidae, and is a native member of the riverine fauna of South America. It is found in Peru and Ecuador, most notably in the Huanaco region, where it inhabits the Rio Aquas, the Rio Amarillae, a tributary of the Rio Pachitea, and the Rio Ucayali river system. The species was first collected by Randolph H. Richards in 1968, and was named Corydoras panda by Nijssen and Isbrücker in 1971. The specific name is an allusion to the appearance of the fish, which possesses large black patches surrounding the eyes, reminiscent of those found on the giant panda. Accordingly, the common names for this fish, which is a popular aquarium species, are panda corydoras and panda catfish.

Dwarf corydoras

The dwarf corydoras (Corydoras hastatus), dwarf catfish, tail spot pygmy catfish, or micro catfish is a tropical freshwater fish belonging to the Corydoradinae sub-family of the Callichthyidae family. It originates in inland waters in South America, and is found in the Amazon River and Paraguay River basins in Argentina, Bolivia, and Brazil. The specific epithet hastatus means with a spear, in reference to the spearhead-like spot on the tail root.

Emerald catfish

The emerald catfish (Corydoras splendens) is a tropical freshwater fish belonging to the Corydoradinae sub-family of the family Callichthyidae native to the Amazon Basin in South America. It has traditionally been known as Brochis splendens. The fish has appeared on a stamp in Brazil.

Han Nijssen

Han Nijssen (1935– 2013) was a Dutch ichthyologist.Nijssen was born in Amsterdam and obtained his PhD at the University of Amsterdam in May 1970 with the dissertation Revision of the Surinam catfishes of the genus Corydoras. Later he was a curator at Zoölogisch Museum in Amsterdam.

Nijssen worked extensively with fish from South America, and was the author of several species, e.g. Corydoras weitzmani and Corydoras xinguensis.

Collaborating with Isaäc Isbrücker he described, among others, the group Hypancistrus and the species Hypancistrus zebra and Corydoras panda.

He also collaborated with Sven O. Kullander.

The species Corydoras nijsseni and Apistogramma nijsseni are named after him.

List of Corydoras species

This is an alphabetically ordered list of Corydoras species.

Each entry includes: binomial scientific name, describer and year of publication.

Some entries are indicated with existing (common name) and synonyms.

List of aquarium fish by scientific name

This page lists all fish commonly kept in aquariums and ponds.

List of freshwater aquarium fish species

A vast number of aquatic species have successfully adapted to live in the freshwater aquarium. This list gives some examples of the most common species found in home aquariums.

Masked corydoras

The masked corydoras, bandit catfish, bandit corydoras, or Meta River corydoras, Corydoras metae, is a tropical freshwater fish belonging to the Corydoradinae sub-family of the family Callichthyidae. It originates in inland waters of South America, and is found in the Meta River basin in Colombia.

The masked corydoras can grow up to 1.8 in (4.8 cm) in length. It lives in a tropical climate in water with a 6.0 - 8.0 pH, a water hardness of 2 - 25 dGH, and a temperature range of 72 - 79°F (22 - 26°C). It feeds on worms, benthic crustaceans, insects, and plant matter. The female holds 2-4 eggs between her pelvic fins, where the male fertilizes them for about 30 seconds. After fertilization the female swims to a suitable spot, where she attaches the very sticky eggs. The masked corydoras lays eggs in dense vegetation without adult protection. The pair repeats this process until about 100 eggs have been fertilized and attached.

The masked corydoras is of commercial importance in the aquarium trade industry.

Sailfin corydoras

The sailfin corydoras (Scleromystax macropterus), bigfin corydoras, or largefin corydoras is a subtropical freshwater fish belonging to the Corydoradinae sub-family of the family Callichthyidae. It originates in coastal rivers in South America, and is found from São Paulo to Santa Catarina, Brazil and some upper Paraná River tributaries. It was originally described, under the name Corydoras macropterus, by C. Tate Regan in 1913.

The fish will grow in length up to 3.4 inches (8.7 centimeters). It lives in a subtropical climate in water with a 6.0 – 8.0 pH, a water hardness of 2 – 25 dGH, and a temperature range of 64 – 70 °F (18 – 21 °C). It feeds on worms, benthic crustaceans, insects, and plant matter. It lays eggs in dense vegetation and adults do not guard the eggs.

The sailfin corydoras is of commercial importance in the aquarium trade industry.

Sterba's corydoras

Sterba's corydoras (Corydoras sterbai) is a member of the South American Corydoras genus of freshwater aquarium catfish and one of the most popular species of Corydoras due to its attractive markings. The fish is native to the Guaporé River region between Bolivia and Brazil.Sterba's cory is distinguishable from other Corydoras species as it has white spots on a black background on its head. It is occasionally confused with Corydoras haraldschultzi; the difference is that the latter has a pattern of black dots on a white background on the head. C. sterbai has recently become available in an albino form and a black form.

Like many Corydoras species, Sterba's corydoras is a shoaling catfish, and thus should ideally be kept in groups of 5 or more. In the wild it can be found in Brazil and thus, wild caught fish prefer soft, acidic water. However, Sterba's corydoras is a hardy fish and tank bred specimens have adapted to a wider range of water conditions. However, like almost all fish it will not tolerate high levels of nitrates.

Unlike some other catfish they are not good algae eaters, but are good at "cleaning up" leftover food and detritus from the substrate.

Corydoras sterbai are relatively small for catfish, growing to a maximum size of only 2–2.6 inches (5.1–6.6 cm).

Sychr's catfish

Sychr's catfish (Corydoras sychri) is a tropical freshwater fish belonging to the Corydoradinae sub-family of the family Callichthyidae. It originates in inland waters in South America, and is found in the Nanay River basin in Loreto, Peru.

The fish grows up to 1.7 inches (4.3 cm). It lives in a tropical climate in water with a 6–8 pH, a water hardness of 2–25 dGH, and a temperature range of 72–79 °F (22–26 °C). It feeds on worms, benthic crustaceans, insects, and plant matter. It lays eggs in dense vegetation and adults do not guard the eggs. The female holds 2–4 eggs between her pelvic fins, where the male fertilizes them for about 30 seconds. Only then does the female swim to a suitable spot, where she attaches the very sticky eggs. The pair repeats this process until about 100 eggs have been fertilized and attached.

Threestripe corydoras

The three stripe corydoras (Corydoras trilineatus), leopard catfish, false julii corydoras, or three line catfish is a tropical freshwater fish belonging to the Corydoradinae sub-family of the Callichthyidae family. It originates in inland waters in South America, and is found in the central Amazon River basin in Brazil and Colombia, Peruvian Amazon and coastal rivers in Suriname.

The fish will grow in length up to 2.5 inches (6.1 centimeters). It lives in a tropical climate in water with a 6.0–8.0 pH, a water hardness of 5–19 dGH, and a temperature range of 72–79 °F (22–26 °C). It feeds on worms, benthic crustaceans, insects, and plant matter. It lays eggs in dense vegetation and adults do not guard the eggs. The female holds 2-4 eggs between her pelvic fins, where the male fertilizes them for about 30 seconds. Only then does the female swim to a suitable spot, where she attaches the very sticky eggs. The pair repeats this process until about 100 eggs have been fertilized and attached.

The threestripe corydoras is of commercial importance in the aquarium trade industry. It is often mistakenly sold as Corydoras julii since C. julii also has a horizontal strip running along the sides of its body. The distinct difference between C. trilineatus and C. julii is in their markings. The hardier and more adaptable C. trilineatus has reticulations, while C. julii is distinguished by its "leopard" spots, although there is also a spotted form of C. trilineatus. They are best differentiated by the stripes on the side. In C. trilineatus, the stripes are much more pronounced and solid than in C. julii.

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