Costello
Tetra Fact Sheet
The Costello Tetra, Hemigrammus hyanuary, is native to the Amazon River basin
and occurs in Brazil and Peru. Another very common name for this fish is the
January Tetra.
The Costello Tetra has some
similarity in appearance to the Head and Tail Light Tetra. The most obvious difference is that the Head
and Tail Light Tetra is a much deep bodied fish.
Origin
The Costello Tetra is native
to Lake Hyanuary
in Brazil
as well as to other areas. The specific
name of hyanuary was taken from this
lake. The common name, “January Tetra”,
is apparently from the same source on the basis that the English translation of
Hyanuary is January. It certainly looks
as if it should be, but I am not convinced that it is. The language of Brazil
is Portuguese, and the word for January is “Janeiro”, as in Rio de Janeiro.
Size
The Costello Tetra can grow to
5 cm (2 inches), long but is usually less than this. It is an elongated fish, so it is a fairly
small one.
Water Conditions
The water the Costello Tetra
comes from in the wild is soft and acidic.
This fish can be acclimatised to harder water, up to about 12 degrees of
general hardness, and water with a pH of as high as 7.5. However, it is more sensitive to water
chemistry than the Head and Tail Light Tetra and many of its other relatives; I
suggest slightly acidic to neutral water, as soft as is practicable. The water needs to be kept clean. Avoid rapid changes in the water conditions.
A temperature of between 23
and 27 degrees C (between 73 and 81 degrees F) is suitable.
Food
The Costello Tetra is an
omnivore with a preference for animal food.
In an aquarium it will eat a high protein fish flake readily, but needs
some live food like Mosquito larvae or Daphnia if possible. When live food is not available, frozen food
like blood worms or brine shrimp can be used to add variety to your fish’s
diet.
Companions
The Costello Tetra is a very
peaceful schooling fish and a school of 6 or more of these attractive fish
makes a good addition to a community tank with other small peaceful fish liking
neutral water at about 24 degrees C.
Sexing
The female is a little plumper than the male. This difference is greater when she is in
breeding condition and is loaded with eggs.
The male has a slightly hooked anal fin.
Breeding
For breeding, the Costello tetra needs very soft, slightly acidic water of
about 25 degrees C (77 degrees F). They
lay their eggs over plants. Unlike many
fish, they are more likely to lay their eggs in the evening after the light
fades than the morning. They are eggs
scatterers and lay over plants.
Raising the
Fry
The eggs normally hatch in about 24 hours and the
babies should be free swimming in another 3 days. They are small and need infusoria at
first. The water quality in important
and will need regular partial water changes with water of the same temperature,
acidity and hardness.
Conservation
Status
In the UICN Red list the Costello Tetra is a species
of least concern with a stable population.
Other Common
Names
In France
the “Costello Tetra” is called “Néon vert” or “Tétra
Costello”. In Germany it is called “Grüner Neon”,
in Denmark, “Costellotetra”
or “Grøn neon”; in Poland, “Zwinnik”
or “zielony”; in Peru, “Mojarita”
or “Enero tetra”; in Sweden,
“Costellotetra”; and in Chinese it is called “豚形半線脂鯉”, “豚形半线脂鲤” or “金线黑灯、一月灯”.
In English the three common names used are “Costello
Tetra”, “January Tetra” and “Green Neon”.
The name Green Neon is quite misleading because this is the common name
of “Paracheirodon simulans” which is
quite different in appearance from “Hemigrammus Hyanuary”.
The common names in several of
the other languages also mean “Green Neon” Some of them are clear equivalents
of Costello Tetra. Only Peru and China uses a translation of January
in one of their names for this fish.
Sources
Fishbase: "http://www.fishbase.org/Summary/SpeciesSummary.php?ID=12367&AT=January+tetra">http://www.fishbase.org/Summary/SpeciesSummary.php?ID=12367&AT=January+tetra
UICN Red list : "http://www.iucnredlist.org/apps/redlist/search">http://www.iucnredlist.org/apps/redlist/search
"http://www.fish3000.com/viewthread.php?tid=723878">http://www.fish3000.com/viewthread.php?tid=723878
