Panda corydoras
Encyclopedia
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
, 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 H.R. 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.
. The fin
s of the fish match the body in ground colour, upon close inspection being seen to be hyaline or translucent with coloured fin rays, with the dorsal fin
being marked by a conspicuous black blotch that covers almost the entire fin area. The caudal peduncle is marked with a black band, this black band encircling the caudal peduncle from dorsal to ventral surface. The adipose fin, supported by a small fin spine, sometimes contains black pigmentation. The head is the same ground colour as the body, with a black mask surrounding the eyes, descending vertically from the fontanel, over each eye, and ending in a triangular wedge immediately before the ventral surface of the head. The pectoral fins are positioned immediately behind the operculum, and are usually oriented horizontally when the fish is at rest, extended in a manner similar to the wings of an aeroplane. The pelvic fins are positioned upon the ventral surface of the fish, located some way behind the pectoral fins. The first ray of the dorsal fin emanates from the body at approximately its point of greatest elevation, and a vertical line drawn downwards from this point meets the attachment point of the pelvic fins. The anal fin is located far to the rear of the ventral surface of the body, the attachment point of the first fin ray being somewhat forward of the black caudal peduncle marking described above.
In common with all other members of the Family Callichthyidae, the body surface is covered, not with scales
, but with bony plates known as scute
s. The lines of demarcation between individual scutes can be seen upon close examination of this and almost all other Callichthyid fishes, and in the case of some specimens of this species, are highlighted by additional black pigment.
The fish possesses, in common with almost all Corydoras species, three pairs of barbel
s - one pair of maxillary barbels and two pairs of rictal barbels.
A fully mature adult specimen of this species attains a standard length of 55 millimetres (2.1 inches): this is the length attained by mature females, which grow larger than mature males, and also possess more rounded body outlines.
mountain range, and the replenishment of those rivers with meltwaters from Andean snows at higher altitudes, has led the fish to be adaptable to cooler temperatures than the norm for 'tropical' fishes - the temperature range of the fish is 16°C to 28°C, though the fish exhibits a marked preference for the cooler regions of this temperature spectrum, particularly in captivity. Indeed, the fish can, for limited periods, survive temperatures as low as 12°C, though captive rearing at such low temperatures is ill-advised. The native waters of Corydoras panda are consequently mineral-deficient, with a neutral to slightly acid pH, and replication of such conditions in captivity are recommended for successful maintenance.
Like many other Corydoras species, the Panda Catfish is a highly gregarious fish, and in common with several other smaller Corydoras species such as C. habrosus and C. pygmaeus, manifests a distinct need for numerous companions of its own species in order to thrive, and can thus be described as being more avowedly social than some of the larger members of the genus. A minimum of eight individuals should be housed in the same aquarium, and if space permits, this number should be revised upwards, as the fish exhibits a very definite preference for grouping together with others of its species. They also associate themselves easily with the Clown loach
and school together in currents where sufficient numbers of their own species is lacking.
An aquarium for this species should be well furnished, ideally with a mixture of live aquatic plants, and solid furnishings providing caves, sheltered areas and hiding places to give the fish security. Floating plants to provide additional areas of shade are also welcomed by the fish.
Like all Corydoras species, the fish feeds primarily upon animal matter. The aquarist is advised, however, that the traditional use of Corydoras catfishes as putative 'scavengers' in an aquarium setting will be detrimental to the well-being of this species - it requires high quality foods for long-term maintenance, and a varied diet. Ideally, the fish should be given live foods at least intermittently, and will dine enthusiastically upon such items as Bloodworms (larvae of Chironomus midges), Daphnia
, cultivated Brine Shrimp
(Atermia salina), and Tubifex
worms. The latter, however, should be cultivated in order to minimise the risk of introducing pathogenic organisms to the aquarium, as Tubifex live in unsanitary conditions in the wild. Freeze dried
Tubifex may be preferable, as the risk of introduction of disease is eliminated. High quality flake foods
are also appreciated, particularly those containing shrimp
or other similar matter.
The lifespan of Corydoras panda in the aquarium has not been systematically determined, but given the longevity of other Corydoras species in the aquarium, it is reasonable to assume that well-cared for specimens will enjoy a lifespan in excess of 10 years, and frequently in excess of 15 years.
. However, while some Corydoras species require a temperature drop in the aquarium for spawning to be stimulated, in the case of Corydoras panda, the temperature drop appears to matter much less, as specimens have spawned in the aquarium without a temperature drop. The addition of new, clean, oxygenated water appears to be the primary stimulus for this species. In the wild, the appearance of new water courtesy of the rains is followed by an increase in the populations of assorted food organisms, and feeding upon these conditions the fishes for breeding.
Once conditioned fishes are stimulated into spawning, males begin chasing females energetically. Females begin developing eggs within their reproductive tracts, and when 'ripe' (laden with eggs), become receptive to the attentions of the males. Eventually, one male will succeed in courting a female, using his barbels to provide stimulation to the female, usually beginning with caresses of the female's caudal peduncle, followed by caresses of the fontanel and the front of the head. if the female is receptive, then the male positions himself before the female, so that the female's mouth is in close proximity with one of the male's pectoral fins. The male then clasps the female's barbels between the pectoral fin and the body, and this stimulates the female to press against the male's side. When seen from above, the fishes form a 'T' shape when conjoined thus, hence the term 'T position' has become conventional in aquarium circles when describing the breeding of Corydoras catfishes.
Once the male and female are in the 'T position', the pressing of the female against the male's body stimulates his release of sperm. Though the exact mechanism of fertilisation has yet to be scientifically documented, from the observations of aquarists who have been successful in breeding Corydoras catfishes, it seems likely that the female takes the male's sperm through her mouthparts, and directs them through the gills, in a current that carries the sperm to her pelvic fins. At this point, the female releases a single egg (occasionally two), and purses her pelvic fins in order to provide a receptacle for the freshly extruded egg, which is then fertilised.
One difference observed between the adoption of the 'T position' in Corydoras panda, when compared to other Corydoras species, is that the exercise is frequently more acrobatic in appearance, with the 'T position' being adopted in mid-water, some distance above the substrate, rather than resting upon the substrate as is the case with the majority of other Corydoras.
Once the female is carrying a fertilised egg within her pelvic fins, she then seeks an egg deposition site. The choice of such a site is frequently, though not always, a mass of fine leaved aquatic vegetation. In the aquarium, the plant known as Java Moss
, Vesicularia dubayana, is of considerable utility as an egg repository for Corydoras catfishes, even though the plant is not a South American native, and Panda Catfish females will choose large clumps of this plant readily as safe deposition sites for fertilised eggs. The female is frequently pursued by one or more males as she seeks the deposition site, each male presumably seeking to be the chosen mate to fertilise the next egg. Up to 25 eggs may be produced by a single female during a single spawning, which may take place over four to five hours.
Upon hatching, the fry are 4 millimetres long, translucent, but already possessing the basic ground colour of the species, and upon close examination, possess fully formed barbels. Even newly hatched fry possess at least some hint of the adult eye patches, and as the fry grow, these patches darken and become more prominent. Even so, at just 4 millimetres in length, the fry are practically invisible against typical aquarium gravel unless seen to move!
The fry take approximately 4 weeks to develop to the point where the finfold, a continuous undifferentiated membrane resembling that seen at the posterior of a tadpole
, has differentiated into the unpaired fins (dorsal, anal and caudal fins). During this time, size will have increased to approximately 8 or 9 millimetres, and the fish will begin to develop colour changes leading to that of the adult fish. From this point, the caudal peduncle patch and dorsal fin patch will begin to appear, but the body will also be seen to be covered in fine black 'pepper dots' between these black patches. Only after a period of 10 to 12 weeks, at which point the fish has assumed a size of 12 to 14 millimetres, will the fish attain the colouration of the adult, and be in all respects a perfect miniature of the parents.
Fry of this species are particularly sensitive to changes in water chemistry and to elevated temperatures. While adult fishes can withstand temperatures of 28°C, fry will die of heat stress if exposed to temperatures above 26°C, and their chances of survival are enhanced if the water temperature is kept at 22°C or below. Water changes made to a nursery aquarium during the first 21 days of life of the fry - the critical period during which they manifest the greatest sensitivity to their environment - must be gradual, and the incoming water conditioned to match that of the existing aquarium water where possible before the water change takes place. While the fry are likely to develop best if given infusoria
as part of their feeding régime, it is possible to raise fry to adulthood entirely upon prepared foods.
Catfish
Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
belonging to the genus Corydoras
Corydoras
Members of the South American Corydoras genus are freshwater temperate and tropical catfish in the armored catfish family , and are commonly referred to as corydorases, cories, or cory catfish.-Taxonomy:...
, of the Family Callichthyidae
Callichthyidae
Callichthyidae is a family of catfishes , called armored catfishes due to the two rows of bony plates running down the length of the body. This family contains some of the most popular freshwater aquarium fish, such as the Corydoras.-Taxonomy:The family derives its name from the Greek words kallis...
, and is a native member of the riverine fauna of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. It is found in Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, 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 H.R. Richards in 1968, and was named Corydoras panda by Nijssen
Han Nijssen
Han Nijssen is a Dutch ichthyologist. He is curator at Zoölogisch Museum in Amsterdam.Nijssen has worked extensively with fish from South America, and is the author of several species, e.g. Corydoras weitzmani and Corydoras xinguensis....
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
Giant Panda
The giant panda, or panda is a bear native to central-western and south western China. It is easily recognized by its large, distinctive black patches around the eyes, over the ears, and across its round body. Though it belongs to the order Carnivora, the panda's diet is 99% bamboo...
. Accordingly, the common names for this fish, which is a popular aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
species, are Panda Corydoras and Panda Catfish.
Physical description
Corydoras panda has an off-white to pinkish-orange ground colour, and when observed under certain lighting conditions, a faint greenish iridescence is present upon the flanks and 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....
. The fin
Fin
A fin is a surface used for stability and/or to produce lift and thrust or to steer while traveling in water, air, or other fluid media, . The first use of the word was for the limbs of fish, but has been extended to include other animal limbs and man-made devices...
s of the fish match the body in ground colour, upon close inspection being seen to be hyaline or translucent with coloured fin rays, with the dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
being marked by a conspicuous black blotch that covers almost the entire fin area. The caudal peduncle is marked with a black band, this black band encircling the caudal peduncle from dorsal to ventral surface. The adipose fin, supported by a small fin spine, sometimes contains black pigmentation. The head is the same ground colour as the body, with a black mask surrounding the eyes, descending vertically from the fontanel, over each eye, and ending in a triangular wedge immediately before the ventral surface of the head. The pectoral fins are positioned immediately behind the operculum, and are usually oriented horizontally when the fish is at rest, extended in a manner similar to the wings of an aeroplane. The pelvic fins are positioned upon the ventral surface of the fish, located some way behind the pectoral fins. The first ray of the dorsal fin emanates from the body at approximately its point of greatest elevation, and a vertical line drawn downwards from this point meets the attachment point of the pelvic fins. The anal fin is located far to the rear of the ventral surface of the body, the attachment point of the first fin ray being somewhat forward of the black caudal peduncle marking described above.
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
, but with bony plates known as scute
Scute
A scute or scutum is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.-Properties:...
s. The lines of demarcation between individual scutes can be seen upon close examination of this and almost all other Callichthyid fishes, and in the case of some specimens of this species, are highlighted by additional black pigment.
The fish possesses, in common with almost all Corydoras species, three pairs of barbel
Barbel (anatomy)
A barbel on a fish is a slender, whiskerlike tactile organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, sturgeon, the zebrafish and some species of shark...
s - one pair of maxillary barbels and two pairs of rictal barbels.
Habitat
Corydoras panda inhabits clear river waters that are relatively fast-flowing, well-oxygenated, and flowing over substrates that may comprise soft sand or fine gravel. These rivers are usually well vegetated with assorted species of aquatic plants. The proximity of the home rivers of the fish to the AndesAndes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
mountain range, and the replenishment of those rivers with meltwaters from Andean snows at higher altitudes, has led the fish to be adaptable to cooler temperatures than the norm for 'tropical' fishes - the temperature range of the fish is 16°C to 28°C, though the fish exhibits a marked preference for the cooler regions of this temperature spectrum, particularly in captivity. Indeed, the fish can, for limited periods, survive temperatures as low as 12°C, though captive rearing at such low temperatures is ill-advised. The native waters of Corydoras panda are consequently mineral-deficient, with a neutral to slightly acid pH, and replication of such conditions in captivity are recommended for successful maintenance.
Aquarium Maintenance
As has already been cited above, the species has a preference for cooler than normal waters when compared to many other popular tropical fish species, and consequently, if it is intended to maintain the fishes in a 'community' aquarium setting, companions should be chosen that share the fish's tolerance or preference for cooler temperatures, around 22°C (72°F) being a good choice of maintenance temperature for the species. Given the cleanliness of the fish's native waters, scrupulous attention to water quality in the aquarium is considerably more important for this fish than for the more domesticated Corydoras species such as C. paleatus or C. aeneus. Additionally, scrupulous attention to aquarium substrate cleanliness is a must, as the fishes are intolerant of poor aquarium maintenance in this area, and succumb to stress and disease rapidly if their aquaria are not kept to a high standard. Despite this, the species remains highly popular with aquarists, upon account of the appearance of the fish, and its lively, vivacious behaviour in a well-planned aquarium setting.Clown loach
The clown loach, Chromobotia macracanthus, is a tropical freshwater fish belonging to the Cobitidae family. It is the sole member of the Chromobotia genus. It originates in inland waters in Indonesia on the islands of Sumatra and Borneo...
and school together in currents where sufficient numbers of their own species is lacking.
An aquarium for this species should be well furnished, ideally with a mixture of live aquatic plants, and solid furnishings providing caves, sheltered areas and hiding places to give the fish security. Floating plants to provide additional areas of shade are also welcomed by the fish.
Like all Corydoras species, the fish feeds primarily upon animal matter. The aquarist is advised, however, that the traditional use of Corydoras catfishes as putative 'scavengers' in an aquarium setting will be detrimental to the well-being of this species - it requires high quality foods for long-term maintenance, and a varied diet. Ideally, the fish should be given live foods at least intermittently, and will dine enthusiastically upon such items as Bloodworms (larvae of Chironomus midges), Daphnia
Daphnia
Daphnia are small, planktonic crustaceans, between 0.2 and 5 mm in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because of their saltatory swimming style...
, cultivated Brine Shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
(Atermia salina), and Tubifex
Tubifex tubifex
Tubifex tubifex, also called the sludge worm, or sewage worm, is a species of tubificid segmented worm that inhabits the sediments of lakes and rivers on several continents...
worms. The latter, however, should be cultivated in order to minimise the risk of introducing pathogenic organisms to the aquarium, as Tubifex live in unsanitary conditions in the wild. Freeze dried
Freeze drying
Freeze-drying is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport...
Tubifex may be preferable, as the risk of introduction of disease is eliminated. High quality flake foods
Fish food
Aquarium fish feed is plant or animal material intended for consumption by pet fish kept in aquariums or ponds. Fish foods normally contain macro nutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately 80% of fishkeeping hobbyists feed their fish...
are also appreciated, particularly those containing shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
or other similar matter.
The lifespan of Corydoras panda in the aquarium has not been systematically determined, but given the longevity of other Corydoras species in the aquarium, it is reasonable to assume that well-cared for specimens will enjoy a lifespan in excess of 10 years, and frequently in excess of 15 years.
Reproduction
Corydoras panda follows, with a few minor deviations, the standard model for breeding for the genus. Stimulus for breeding consists of the influx of cooler, oxygenated waters into their habitat, usually corresponding in the wild with the onset of the rainy seasonWet season
The the wet season, or rainy season, is the time of year, covering one or more months, when most of the average annual rainfall in a region occurs. The term green season is also sometimes used as a euphemism by tourist authorities. Areas with wet seasons are dispersed across portions of the...
. However, while some Corydoras species require a temperature drop in the aquarium for spawning to be stimulated, in the case of Corydoras panda, the temperature drop appears to matter much less, as specimens have spawned in the aquarium without a temperature drop. The addition of new, clean, oxygenated water appears to be the primary stimulus for this species. In the wild, the appearance of new water courtesy of the rains is followed by an increase in the populations of assorted food organisms, and feeding upon these conditions the fishes for breeding.
Once the male and female are in the 'T position', the pressing of the female against the male's body stimulates his release of sperm. Though the exact mechanism of fertilisation has yet to be scientifically documented, from the observations of aquarists who have been successful in breeding Corydoras catfishes, it seems likely that the female takes the male's sperm through her mouthparts, and directs them through the gills, in a current that carries the sperm to her pelvic fins. At this point, the female releases a single egg (occasionally two), and purses her pelvic fins in order to provide a receptacle for the freshly extruded egg, which is then fertilised.
One difference observed between the adoption of the 'T position' in Corydoras panda, when compared to other Corydoras species, is that the exercise is frequently more acrobatic in appearance, with the 'T position' being adopted in mid-water, some distance above the substrate, rather than resting upon the substrate as is the case with the majority of other Corydoras.
Once the female is carrying a fertilised egg within her pelvic fins, she then seeks an egg deposition site. The choice of such a site is frequently, though not always, a mass of fine leaved aquatic vegetation. In the aquarium, the plant known as Java Moss
Java moss
Java Moss is a moss belonging to the Hypnaceae family. Native to Southeast Asia, it is commonly used in freshwater aquariums. It attaches to rocks, roots, and driftwood...
, Vesicularia dubayana, is of considerable utility as an egg repository for Corydoras catfishes, even though the plant is not a South American native, and Panda Catfish females will choose large clumps of this plant readily as safe deposition sites for fertilised eggs. The female is frequently pursued by one or more males as she seeks the deposition site, each male presumably seeking to be the chosen mate to fertilise the next egg. Up to 25 eggs may be produced by a single female during a single spawning, which may take place over four to five hours.
Development
Fertile Corydoras panda eggs require approximately 3-4 days development time before hatching, if kept at a temperature of 22°C. This development time will vary with temperature, taking longer in cooler water.Upon hatching, the fry are 4 millimetres long, translucent, but already possessing the basic ground colour of the species, and upon close examination, possess fully formed barbels. Even newly hatched fry possess at least some hint of the adult eye patches, and as the fry grow, these patches darken and become more prominent. Even so, at just 4 millimetres in length, the fry are practically invisible against typical aquarium gravel unless seen to move!
The fry take approximately 4 weeks to develop to the point where the finfold, a continuous undifferentiated membrane resembling that seen at the posterior of a tadpole
Tadpole
A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...
, has differentiated into the unpaired fins (dorsal, anal and caudal fins). During this time, size will have increased to approximately 8 or 9 millimetres, and the fish will begin to develop colour changes leading to that of the adult fish. From this point, the caudal peduncle patch and dorsal fin patch will begin to appear, but the body will also be seen to be covered in fine black 'pepper dots' between these black patches. Only after a period of 10 to 12 weeks, at which point the fish has assumed a size of 12 to 14 millimetres, will the fish attain the colouration of the adult, and be in all respects a perfect miniature of the parents.
Infusoria
Infusoria is a collective term for minute aquatic creatures like ciliates, euglenoids, protozoa, and unicellular algae that exist in freshwater ponds...
as part of their feeding régime, it is possible to raise fry to adulthood entirely upon prepared foods.