x-ray tetra or Pristella
is a wide bodied fish that
is popular among aquarium owners because of is translucent body. X-rays
have an iridescent sheen to them under aquarium lighting. They are a
smaller variety fish reaching only 1.5 to 2 inches in length. Males
tend to slimmer than females.
Since this is the last article on tetras, we will review them as a
family. Tetras are members of the family Characidae
more commonly known
as characids. They are endemic to the Americas. They inhabit the
freshwaters of southwest Texas through Central all the way down to
South America. Many are native to the Amazon River. Characids have a
life span of approximately five years.
Tetras are a peaceful, hardy fish. They make a good choice for
novice aquarists. They make suitable
community fish but have a tendency
to be fin nippers. This behavior is more prominent in larger groupings.
Avoid mixing large finned species such as angelfish, bettas and fancy
guppies with tetras.
Tetras are extremely social. They are shoaling fish. Shoaling fish
function best in a group. They may survive in an aquarium without other
members of their species but it is not recommended. You will want to
keep at least four tetras. Six or more is ideal.
Tetras come in several varieties. Some are slender bodied like cardinals
have wide bodies. Black skirt
are among the wide bodied variety along with x-ray tetras.
There are three translucent tetras commonly sold in fish stores. Theses
are the red phantoms, the black phantoms, and of course the x-ray
tetra. There is even a species commonly referred to as a cave tetra.
These fish have dwelt in a light-less environment for so long that they
are blind. Tetras have been selectively bred by the aquarium trade
industry. The golden neon tetra is a very popular result of this
Tetras thrive in soft, slightly acidic water common the rivers of
South America. The ideal pH level is around 6.8. They prefer water
temperatures between 72-77 °F but will easily tolerate
from 70-80 °F.
Tetras are omnivorous. They can be fed a diet consisting entirely
of common variety tropical fish flakes. But a diet high in protein will
help them maintain their vigor and body color. A diet high in protein
will also help to initiate their spawning cycle. They will readily eat
brine shrimp, tubifex, bloodworms, frozen and freeze-dried foods. Small
amounts of powdered eggs are a good alternative to store bought protein
based foods. Do not over feed them if you choose powdered eggs. You
foul up your water.
are a prolific
species. It is not uncommon for their
population to double in just over a year in the wild. With the
exception of the bleeding heart tetra, tetras are rather easy to breed
Tetras can be induced to spawn when provided with a suitable
environment. They will require soft water, slightly acidic water. Water
softness can be achieved by filling the breeding tank with bottled of
reverse osmosis filtered water. Water acidity should be around pH 6.5.
Ph levels can be altered chemically. A natural solution is to filter
the water through peat. Or you can add a thin layer to the breeding
tank substrate. Peat releases humic acid into the water raising acidity
levels. Make certain the peat contains no fertilizers or chemical
Subdued lighting is essential for two reasons. Tetras are less apt
to spawn under bright lighting. Tetra eggs are vulnerable to fungal
growth. Intense lighting promotes fungal growth.
Tetras are egg layers who scatter their eggs. Characids do not
demonstrate the parental instinct found in fish such as cichlids.
Cichlids will guard their eggs whereas tetras will eat them. A good
trick to insuring a maximum survival rate is by adding a layer of
marbles to the bottom of the aquarium. Their eggs sink. They will slip
down in between the marbles and out of the reach of adults. Adult
tetras should be removed from the breeding tank immediately after
typically 24 hours. Fry will become free swimming
in 2-3 days. Fry can be fed newly hatched brine shrimp or liquid fry
food formulated for egg layers.
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