Neon tetra
Encyclopedia
The neon tetra is a freshwater
fish
of the characin family
(family Characidae
) of order
Characiformes
. The type species
of its genus, it is native to blackwater or clearwater streams in southeastern Colombia
, eastern Peru
, and western Brazil
, including the tributaries of the Solimões
where the water is between 20–26 °C (68–78.8 F). It is not found in the whitewater
rivers of Andean
origin. Its bright colouring makes the fish visible to conspecifics
in the dark blackwater streams, and is also the main reason for its popularity among tropical fish hobbyists
.
. The fish is characterized by an iridescent blue horizontal stripe along each side of the fish from its nose to the base of the adipose fin, and an iridescent red stripe that begins at the middle of the body and extends posteriorly to the base of the caudal fin. Most, if not all, will develop an olive green sheen lining their backs. The fish is completely transparent (including fins) except for these markings. During the night, the blue and red become silver as the fish rests—it reactivates once it becomes active in the morning. It grows to approximately 3 cm (1.2 in) in overall length. Sexual dimorphism
is slight, the female having a slightly larger belly, and a bent iridescent stripe rather than the male's straight stripe.
and was described by renowned ichthyologist Dr. George S. Myers
in 1936, and named after Dr. William T. Innes
. P. innesi is one of the most popular aquarium
fish, having been bred in tremendous numbers for the trade. Most neon tetras available in the United States are imported from Hong Kong
, Singapore
, and Thailand
, where they are farm raised, or to a lesser extent (<5%) from Colombia
, Peru
, and Brazil
, where they are collected from the wild. During a single month, an average of 1.8 million neon tetras with an estimated value of $175,000 are imported into the United States for the aquarium trade. With the exception of home aquarists and a few commercial farms that breed neon tetras experimentally, captive breeding on a commercial scale is nonexistent in the United States.
Neon tetras are considered easy to keep in a community aquarium that is at least 60 cm (24 inches), with a pH of 6.0–7.8 and KH of 1.0–2.0. However, they will die if traumatized by dramatic changes to their environment. They tend to be timid and, because of their small size, should not be kept with large or aggressive fish who may bully or simply eat them. Fish that mix well in an aquarium are guppies
, other types of tetras, such as the rummy-nose tetra
, cardinal tetra
, and glowlight tetra, and other community fish that live well in an ideal tetra water condition. Mid-level feeders, they are best kept in schools of six or more, for the shoaling
effect when they move around the tank. They shoal naturally in the wild and are thus happier, more brightly colored, and more active when kept as a shoal as opposed to singly. Their colour and the iridescent stripe may become dim at night, and can be virtually invisible after a period of darkness. The color may also fade during a period of stress, such as human intervention into the tank. Neons are best kept in a densely planted tank with subdued light and an ideal temperature of 21–27 °C (69.8–80.6 F) to resemble their native Amazon environment.
s and will accept most flake foods, if sufficiently small, but should also have some small foods such as brine shrimp
, daphnia
, freeze-dried bloodworms, tubifex
, which can be stuck to the side of the aquarium, and micro pellet food to supplement their diet. A tropical sinking pellet is ideal as most brands of these include natural color enhancers that bring out the color in neon tetras. Some frozen foods including frozen blood worms add variety to their diet.
To breed Neon Tetras, place a pair of the species in a breeding tank without any light, and gradually increase the lighting until spawning
occurs. Other inducers include mosquito larvae and a hardness of less than 4 degrees. Some also recommend letting the level of nitrates rise, then do at least 50% water change to simulate the fresh rain the tetras get in their natural habitat, the Amazon. It is recommended that everything you place in the aquarium be sterilized, as well as the aquarium top. Because the adults will often eat newly-hatched fry
, it is best to remove them as soon as the eggs have been laid. The eggs are especially sensitive to light. Eggs will hatch
within 24 hours of the laying. Fry
can be fed infusoria
, especially rotifers and egg yolk
for 1 to 4 weeks, followed by nauplii of brine shrimp, shaved cattle liver, and formulated diets. Fry will achieve their adult coloration at approximately one month of age. Adults can spawn every two weeks.
The disease cycle begins when microsporidian parasite spores enter the fish after it consumes infected material such as the bodies of a dead fish, or live food
such as tubifex
, which may serve as intermediate host
s. The disease is most likely to be passed on from newly acquired fish, which have not been quarantined.
Symptoms:
Note that there is a so-called "false neon disease", which is bacterial, and shows very similar symptoms. It is impossible for the home aquarist to determine for certain the difference between NTD and false NTD on the basis of visible symptoms alone, without laboratory backup. This disease has also been confused with Columnaris
(mouth rot, mouth fungus, 'flex').
To date, there is no known cure: the only 'treatment' is the immediate removal of diseased fish to preserve the remaining fish, but no way to save the diseased fish. The use of a diatom filter, which can reduce the number of free parasites in the water, may help.
(P. simulans) and black neon tetra
(Hyphessobrycon herbertaxelrodi) are distinct species—the latter belong to an altogether different genus
—and not color varieties. The cardinal tetra
(P. axelrodi)—also sometimes called the red neon—is a very similar species, and is often confused with the true neon tetra. In a domestic aquarium, the two species will school together, especially if there are insufficient of one of the species to form a school. The neon tetra will also school with P. simulans if there are only a few of each. The cardinal tetra's larger size and greater extent of red coloring distinguishes it from the neon tetra. The term Hyphessobrycon innesi does not denote a species, it is an obsolete synonym for P. innesi, the neon tetra itself.
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
of the characin family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
(family 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...
) of order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Characiformes
Characiformes
The Characiformes are an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, there are a few thousand different species, including the well-known piranha and tetras.-Taxonomy:...
. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of its genus, it is native to blackwater or clearwater streams in southeastern Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, eastern 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....
, and western Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, including the tributaries of the Solimões
Solimões
Solimões is the name often given to early stretches of the Amazon River from the border of Brazil and Peru to its confluence with the Rio Negro.Further upstream from the border, the name of the river seems to depend on the speaker...
where the water is between 20–26 °C (68–78.8 F). It is not found in the whitewater
Whitewater
Whitewater is formed in a rapid, when a river's gradient increases enough to disturb its laminar flow and create turbulence, i.e. form a bubbly, or aerated and unstable current; the frothy water appears white...
rivers of Andean
Andes
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...
origin. Its bright colouring makes the fish visible to conspecifics
Conspecificity
Conspecificity is a concept in biology. Two or more individual organisms, populations, or taxa are conspecific if they belong to the same species....
in the dark blackwater streams, and is also the main reason for its popularity among tropical fish hobbyists
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...
.
Description
The neon tetra has a light-blue back over a silver-white abdomenAbdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
. The fish is characterized by an iridescent blue horizontal stripe along each side of the fish from its nose to the base of the adipose fin, and an iridescent red stripe that begins at the middle of the body and extends posteriorly to the base of the caudal fin. Most, if not all, will develop an olive green sheen lining their backs. The fish is completely transparent (including fins) except for these markings. During the night, the blue and red become silver as the fish rests—it reactivates once it becomes active in the morning. It grows to approximately 3 cm (1.2 in) in overall length. Sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
is slight, the female having a slightly larger belly, and a bent iridescent stripe rather than the male's straight stripe.
Economics
The neon tetra was first imported from South AmericaSouth 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...
and was described by renowned ichthyologist Dr. George S. Myers
George S. Myers
Dr. George Sprague Myers spent most of his career at Stanford University, where he was one of the leading American ichthyologists of the twentieth century. He served as the editor of Stanford Ichthyological Bulletin as well as president of the American Society of Ichthyologists and Herpetologists...
in 1936, and named after Dr. William T. Innes
William T. Innes
William Thornton Innes III, L.H.D. was an American aquarist, author, photographer, printer and publisher. Innes was the author of numerous influential books and hundreds of articles about aquarium fish, aquatic plants and aquarium maintenance during the formative years of the aquarium hobby in...
. P. innesi is one of the most 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...
fish, having been bred in tremendous numbers for the trade. Most neon tetras available in the United States are imported from Hong Kong
Hong Kong
Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...
, Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
, and Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, where they are farm raised, or to a lesser extent (<5%) from Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, 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....
, and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, where they are collected from the wild. During a single month, an average of 1.8 million neon tetras with an estimated value of $175,000 are imported into the United States for the aquarium trade. With the exception of home aquarists and a few commercial farms that breed neon tetras experimentally, captive breeding on a commercial scale is nonexistent in the United States.
In the aquarium
While commercially bred neon tetras have adapted well to a wide range of water conditions, in the wild they inhabit very soft, acidic waters that are usually cooler than the 25 °C (77 °F) most tropical aquaria are maintained at. They can have a lifespan of up to ten years, normally about five in an aquarium.Neon tetras are considered easy to keep in a community aquarium that is at least 60 cm (24 inches), with a pH of 6.0–7.8 and KH of 1.0–2.0. However, they will die if traumatized by dramatic changes to their environment. They tend to be timid and, because of their small size, should not be kept with large or aggressive fish who may bully or simply eat them. Fish that mix well in an aquarium are guppies
Guppy
The guppy , also known as the millionfish, is one of the most popular freshwater aquarium fish species in the world. It is a small member of the Poeciliidae family [females long, males long] and like all other members of the family, is live-bearing....
, other types of tetras, such as the rummy-nose tetra
Rummy-nose tetra
The rummy-nose tetra, Hemigrammus rhodostomus, is a species of tropical freshwater characin fish originating from South America, popular among fishkeepers as an aquarium fish. One of many small tetras belonging to the same Genus, it is a 5 cm long fish when fully grown, and is a long...
, cardinal tetra
Cardinal tetra
The cardinal tetra, Paracheirodon axelrodi, is a freshwater fish of the characin family of order Characiformes. It is native to the upper Orinoco and Negro Rivers in South America....
, and glowlight tetra, and other community fish that live well in an ideal tetra water condition. Mid-level feeders, they are best kept in schools of six or more, for the shoaling
Shoaling and schooling
In biology, any group of fish that stay together for social reasons are said to be shoaling , and if, in addition, the group is swimming in the same direction in a coordinated manner, they are said to be schooling . In common usage, the terms are sometimes used rather loosely...
effect when they move around the tank. They shoal naturally in the wild and are thus happier, more brightly colored, and more active when kept as a shoal as opposed to singly. Their colour and the iridescent stripe may become dim at night, and can be virtually invisible after a period of darkness. The color may also fade during a period of stress, such as human intervention into the tank. Neons are best kept in a densely planted tank with subdued light and an ideal temperature of 21–27 °C (69.8–80.6 F) to resemble their native Amazon environment.
Nutrition
Neon tetras are omnivoreOmnivore
Omnivores are species that eat both plants and animals as their primary food source...
s and will accept most flake foods, if sufficiently small, but should also have some small foods such as 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...
, 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...
, freeze-dried bloodworms, tubifex
Tubifex
Tubifex is a cosmopolitan genus of tubificid Annelids that inhabit the sediments of lakes, rivers and occasionally sewer lines. There are over ten known species of Tubifex, but the number is not certain, as the species are not easily distinguishable from each other.-Food and feeding:Tubifex worms...
, which can be stuck to the side of the aquarium, and micro pellet food to supplement their diet. A tropical sinking pellet is ideal as most brands of these include natural color enhancers that bring out the color in neon tetras. Some frozen foods including frozen blood worms add variety to their diet.
Breeding
The male is slender, and the blue line is straighter. The female is rounder, producing a bent blue line. Some say that the females look plumper when viewed from above but this is disputed. However, the 'straightness' of the line and the plumpness of the female might occasionally be due to the eggs she is carrying.To breed Neon Tetras, place a pair of the species in a breeding tank without any light, and gradually increase the lighting until spawning
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
occurs. Other inducers include mosquito larvae and a hardness of less than 4 degrees. Some also recommend letting the level of nitrates rise, then do at least 50% water change to simulate the fresh rain the tetras get in their natural habitat, the Amazon. It is recommended that everything you place in the aquarium be sterilized, as well as the aquarium top. Because the adults will often eat newly-hatched fry
Fry
-Food and cooking:* Frying, the act of cooking food in oil or fat** Pan frying, frying food in a flat pan** Stir frying, frying food in a wok and stirring it while it cooks* Full breakfast, a traditional cooked meal, also called a fry-up or Ulster fry...
, it is best to remove them as soon as the eggs have been laid. The eggs are especially sensitive to light. Eggs will hatch
Hatch
Hatch may refer to:* Hatching, also called "cross-hatching", an artistic technique used to create tonal or shading effects using closely spaced parallel lines* Hatching, the emergence of a young animal from an egg...
within 24 hours of the laying. Fry
Fry
-Food and cooking:* Frying, the act of cooking food in oil or fat** Pan frying, frying food in a flat pan** Stir frying, frying food in a wok and stirring it while it cooks* Full breakfast, a traditional cooked meal, also called a fry-up or Ulster fry...
can be fed infusoria
Infusoria
Infusoria is a collective term for minute aquatic creatures like ciliates, euglenoids, protozoa, and unicellular algae that exist in freshwater ponds...
, especially rotifers and egg yolk
Egg yolk
An egg yolk is a part of an egg which feeds the developing embryo. The egg yolk is suspended in the egg white by one or two spiral bands of tissue called the chalazae...
for 1 to 4 weeks, followed by nauplii of brine shrimp, shaved cattle liver, and formulated diets. Fry will achieve their adult coloration at approximately one month of age. Adults can spawn every two weeks.
Disease
Unfortunately, neon tetras are occasionally afflicted by the so-called "Neon Tetra Disease" (NTD) or Pleistophora, a sporozoan disease caused by Pleistophora hyphessobryconis. Despite being a well-known condition, it is currently incurable and often fatal to the fish.The disease cycle begins when microsporidian parasite spores enter the fish after it consumes infected material such as the bodies of a dead fish, or live food
Live food
Live food is living food for carnivorous or omnivorous animals kept in captivity; in other words, small animals such as insects or mice fed to larger carnivorous or omnivorous species kept in either in a zoo or as pet....
such as tubifex
Tubifex
Tubifex is a cosmopolitan genus of tubificid Annelids that inhabit the sediments of lakes, rivers and occasionally sewer lines. There are over ten known species of Tubifex, but the number is not certain, as the species are not easily distinguishable from each other.-Food and feeding:Tubifex worms...
, which may serve as intermediate host
Intermediate host
A secondary host or intermediate host is a host that harbors the parasite only for a short transition period, during which some developmental stage is completed. For trypanosomes, the cause of sleeping sickness, humans are the primary host, while the tsetse fly is the secondary host...
s. The disease is most likely to be passed on from newly acquired fish, which have not been quarantined.
Symptoms:
- Restlessness.
- Fish begins to lose coloration.
- As cysts develop, the body may become lumpy.
- Fish has difficulty swimming.
- In advanced cases the spine may become curved.
- Secondary infections such as fin rot and bloating.
Note that there is a so-called "false neon disease", which is bacterial, and shows very similar symptoms. It is impossible for the home aquarist to determine for certain the difference between NTD and false NTD on the basis of visible symptoms alone, without laboratory backup. This disease has also been confused with Columnaris
Columnaris
Columnaris is a symptom of disease in fish which results from an infection caused by the gram negative, aerobic, rod shaped bacterium Flavobacterium columnare. It was previously known by the names of bacillus columnaris, chondrococcus columnaris, cytophaga columnaris and flexibacter columnaris...
(mouth rot, mouth fungus, 'flex').
To date, there is no known cure: the only 'treatment' is the immediate removal of diseased fish to preserve the remaining fish, but no way to save the diseased fish. The use of a diatom filter, which can reduce the number of free parasites in the water, may help.
Related species and other "neon tetras"
The green neon tetraGreen neon tetra
The green neon tetra is a freshwaterfish of the characin family of order Characiformes. It is native to the upper Orinoco and Negro Rivers in South America....
(P. simulans) and black neon tetra
Black neon tetra
The black neon tetra is a freshwater fish of the characinfamily oforder Characiformes. It is native to theParaguay basin of southern Brazil....
(Hyphessobrycon herbertaxelrodi) are distinct species—the latter belong to an altogether different genus
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...
—and not color varieties. The cardinal tetra
Cardinal tetra
The cardinal tetra, Paracheirodon axelrodi, is a freshwater fish of the characin family of order Characiformes. It is native to the upper Orinoco and Negro Rivers in South America....
(P. axelrodi)—also sometimes called the red neon—is a very similar species, and is often confused with the true neon tetra. In a domestic aquarium, the two species will school together, especially if there are insufficient of one of the species to form a school. The neon tetra will also school with P. simulans if there are only a few of each. The cardinal tetra's larger size and greater extent of red coloring distinguishes it from the neon tetra. The term Hyphessobrycon innesi does not denote a species, it is an obsolete synonym for P. innesi, the neon tetra itself.