tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...
Upper Amazon
The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile.
The headwaters of th ...
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...
. It was first described by the Dutch ichthyologists
Isaäc J. H. Isbrücker
Isaäc Jan Hendrik Isbrücker (born 1944) is a retired Dutch ichthyologist who specialised in the scientific classification of South American catfish (Loricarioidea).
Life and work
Between 1960 and 1985 Isbrücker was a keeper of the aquarium in ...
in 1983, and is frequently seen in the
aquarium trade
Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture.
Origins of fishkeeping
Fish hav ...
.
Naming and etymology
Its generic name, ''Corydoras'', is derived from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
''kory'' (helmet) and ''doras'' (skin). Its
specific name Specific name may refer to:
* in Database management systems, a system-assigned name that is unique within a particular database
In taxonomy, either of these two meanings, each with its own set of rules:
* Specific name (botany), the two-part (bino ...
, ''imitator'', alludes to its visual similarity to other members of its genus.
In other languages
In
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national id ...
: imitator armored catfish).
In
Mandarin Chinese
Mandarin (; ) is a group of Chinese (Sinitic) dialects that are natively spoken across most of northern and southwestern China. The group includes the Beijing dialect, the basis of the phonology of Standard Chinese, the official language ...
Simplified Chinese
Simplification, Simplify, or Simplified may refer to:
Mathematics
Simplification is the process of replacing a mathematical expression by an equivalent one, that is simpler (usually shorter), for example
* Simplification of algebraic expressions ...
: 仿兵鲇;
pinyin
Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally written in Chinese fo ...
: fǎng bīng nián;
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national id ...
: imitation soldier catfish).
Morphology and physiology
Description
''Corydoras imitator'' is a small species of
catfish
Catfish (or catfishes; order Siluriformes or Nematognathi) 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 three largest species alive, ...
, with adults typically growing to a length of to . It is
sexually dimorphic
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
, with sexually mature females tending to grow larger, broader, and deeper-bodied than males. As with all members of the genus ''Corydoras'', ''C. imitator'' is completely scaleless, and is instead covered with bony plates known as
scutes
A scute or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior po ...
.
Coloration
Corydoras imitator is white in coloration, with an oblique dark band running across the dorsal surface of its body. It bears a similar coloration pattern to several other members of its genus that inhabit the Rio Negro region (hence its name), including C. adolfoi, C. burgessi, C. davidsandsi, C. duplicareus, C. melini, and C. serratus. These catfish oftentimes form large mixed schools amongst each other, and may even interbreed.
Venom
Like several other ''Corydoras'' species, such as '' C. adolfoi'' and '' C. panda'', ''Corydoras imitator'' secretes a mild
venom
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a ...
glands
In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland).
Structure
De ...
at the base of each pectoral-fin spine in order to protect itself from predators. When stiffened, these spines are capable of penetrating human skin and causing significant pain in conjunction with the venom.
Distribution and habitat
''Corydoras imitator'' is native to the upper Rio Negro basin in
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...
in
Amazonas, Brazil
Amazonas () is a state of Brazil, located in the North Region in the northwestern corner of the country. It is the largest Brazilian state by area and the 9th largest country subdivision in the world, and the largest in South America, being g ...
, northern Brazil, and
Amazonas, Venezuela
)
, anthem = '' Himno del Estado Amazonas''
, image_map = Amazonas in Venezuela.svg
, map_alt =
, map_caption = Location within Venezuela
, pushpin_map =
, pushpin_map ...
. It is found in a pH range of 6.0 to 8.0, in depths between and , and in
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
temperatures of to . It primarily inhabits blackwater rivers with low hardness, low conductivity, and relatively high acidity. It shares its habitat with small characids, pencil fishes, and dwarf cichlids from the genus
Apistogramma
''Apistogramma'' is a large genus of freshwater fish in the family Cichlidae found in South America, but also commonly kept in aquariums. They are dwarf cichlids that mostly feed on tiny animals and have breeding behaviors that vary depending o ...
. The type locality is
Ecology
Behavior
''Corydoras imitator'' is a peaceful and
gregarious
Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies.
Sociality is a survival response to evolutionary pressures. For example, when a mother w ...
fish, and well-suited to a
community aquarium
Community aquaria are tanks that are designed to contain more than one species of fish. Most commonly they include a variety of species that do not normally occur together in nature, for example angelfish from Brazil, swordtails from Mexico, and ...
. Care should be taken not to house them with aggressive fish, as they may get harmed by ''C. imitators venomous spines if they try to nip them.
An unusual behavior that ''Corydoras imitator'' exhibits is occasionally rising to surface of the water and taking in gulps of air before submerging. This is not necessarily indicative of oxygen deprivation, but rather because ''C. imitator'' and other members of the ''Corydoras'' genus are
facultative
{{wiktionary, facultative
Facultative means "optional" or "discretionary" (antonym '' obligate''), used mainly in biology in phrases such as:
* Facultative (FAC), facultative wetland (FACW), or facultative upland (FACU): wetland indicator statuses ...
air-breathers, similar to
Siamese fighting fish
The Siamese fighting fish (''Betta splendens''), commonly known as the betta, is a freshwater fish native to Southeast Asia, namely Cambodia, Laos, Myanmar, Malaysia, Indonesia, Thailand, and Vietnam. It is one of 73 species of the genus '' B ...
and
tarpon
Tarpons are fish of the genus ''Megalops''. They are the only members of the family Megalopidae. Of the two species, one (''M. atlanticus'') is native to the Atlantic, and the other (''M. cyprinoides'') to the Indo-Pacific Oceans.
Species an ...
. They possess a heavily modified
intestine
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...
, which allows them to take in atmospheric oxygen and survive in low-oxygen environments.
Diet
''Corydoras imitator'' is a
foraging
Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...
omnivore
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...
, and primarily feeds on
zoobenthos
Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commu ...
and plant matter. In the aquarium, it will readily accept most sinking dry foods, as well as live or frozen
brine shrimp
''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia L ...
Tubifex
''Tubifex'' is a cosmopolitan genus of tubificid annelids that inhabits the sediments of lakes, rivers and occasionally sewer lines. At least 13 species of ''Tubifex'' have been identified, with the exact number not certain, as the species a ...
'' worms.
Reproduction
In the aquarium, ''Corydoras imitator'' breeds similarly to other ''Corydoras'' species, such as '' C. aeneus''. In order to facilitate breeding, a
sex ratio
The sex ratio (or gender ratio) is usually defined as the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. Many species de ...
of two males to one female is recommended. When females are visibly
gravid
In biology and human medicine, gravidity and parity are the number of times a woman is or has been pregnant (gravidity) and carried the pregnancies to a viable gestational age (parity). These terms are usually coupled, sometimes with additional t ...
, a large water change (50-70%) with cooler water should be performed daily until the eggs hatch, and oxygenation and flow should be increased. ''C. imitator'' eggs are often deposited on aquarium glass and among fine-leaved vegetation. It is recommended to place a spawning mop in the aquarium in order to facilitate the easy removal of eggs, as C. imitator will also readily deposit its eggs on them too.
Once spawning is complete, all eggs should be moved to a separate tank in order to avoid predation. This tank should have the same water as the tank the eggs were spawned in, and should have similar levels of
oxygenation
Oxygenation may refer to:
* Oxygenation (environmental), a measurement of dissolved oxygen concentration in soil or water
* Oxygen saturation (medicine), the process by which concentrations of oxygen increase within a tissue
* Water oxygenation, t ...
as well. Incubation takes place for 3-4 days, after which the eggs will hatch. When the fry fully absorb their yolk sacs, it is recommended to feed them small live food such as
brine shrimp
''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia L ...
and
microworms
The free-living nematode ''Panagrellus redivivus'' (sour paste nematode, or beer mat nematode from its occurrence in constantly moist felt beer mats), is known to many aquarium enthusiasts and fish keepers as the microworm. It is a tiny roundwo ...
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
; it is, however, frequently seen in the
aquarium trade
Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture.
Origins of fishkeeping
Fish hav ...
.
In the aquarium
Like other ''Corydoras'' species, ''C. imitator'' is a common sight within the aquarium trade. A minimum tank size of 90 x 30 cm is recommended, as they should ideally be kept in
shoals
In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material and rises from the bed of a body of water to near the surface. It ...
of at least four to six individuals. The ideal water conditions are a
temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer.
Thermometers are calibrated in various temperature scales that historically have relied on ...
hardness
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion (mechanical), abrasion. In general, different materials differ in their hardn ...
of 18 to 90 ppm. The ideal substrate is fine
sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a soil texture, textur ...
, but rounded gravel is an acceptable alternative, provided that it is regularly cleaned. Cover, such as driftwood branches and dried leaf litter, should be provided to give ''C. imitator'' a sense of security.