Page 101 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

CHARACOIDS/TETRAS 99

Hyphessobrycon bifasciatus Paracheirodon axelrodi
TETRA BIOLOGY
Yellow Tetra Cardinal Tetra
Tetras are lively, active fish that instinctively
stay close together as a shoal. A torpedolike ORIGINS South America, specifically the southeastern ORIGINS Tributaries of the Rio Negro and Orinoco in the
body shape makes them suitable for the middle region of Brazil, in the vicinity of Rio de Janeiro. northwestern region of South America.
and upper layers of the tank. Their streamlining SIZE 2 ⁄2 in (6.5 cm). SIZE Up to 2 in (4.5 cm).
1
enables them to swim fast, which is important DIET Prepared foods and small live foods. DIET Prepared foods, such as flake, and small live foods.
in the wild because their small size leaves WATER Temperature 68–77°F (20–25°C); hard WATER Temperature 73–79°F (23–26°C); soft
them vulnerable to attack. They have good (100–150 mg/l) and neutral (pH 7.0). (0–50 mg/l) and acidic (pH 5.8).
eyesight, however, which makes it difficult TEMPERAMENT Social and placid. TEMPERAMENT Social; should be kept in shoals.
for predators to approach a shoal without
being detected. Tetras can also hear Not to be confused with the Lemon Tetra (H.
underwater sounds, thanks to a connection pulchripinnis), the Yellow Tetra has two dark bands
between their swim bladder and inner ear. just behind the gills. These are most apparent in
males, which are more brightly colored overall.
The males also have a more concave anal fin than
the females. Successful spawning is not difficult to
achieve if the fish are in good condition. Fry foods
intended for egg-laying species can be used for the
young tetras once they are free-swimming.

Yellow coloration One of the most beautiful of all freshwater fish,
along upper body the Cardinal Tetra can have its coloration enhanced
by good water conditions. It is not an easy
species to breed, but the use of blackwater
extract may help to encourage reproductive
behavior. Cardinal Tetras need to be transferred
to a separate tank for spawning purposes. The
eggs hatch in about a day, with the fry becoming
free-swimming about five days later.

Paracheirodon innesi
Neon Tetra

ORIGINS Occurs only in Rio Putumayo in eastern Peru,
South America.
SIZE 1 ⁄2 in (4 cm).
1
DIET Prepared foods and small live foods.
WATER Temperature 68–79°F (20–26°C); soft
(50–100 mg/l) and acidic (pH 6.0).
TEMPERAMENT Highly social.
These tetras are so beautiful that when they first
became available to aquarists in the 1930s, they
sold for the equivalent of more than a month’s
wages. Today, they are likely to be found in
almost every tropical fish store, being widely bred
commercially. There are now even variants—
including a yellow strain, christened “Mon Cheri,”
and a long-finned strain—although none rivals the
natural form in popularity. Neons can
be easily distinguished at a glance
from Cardinal Tetras (see top right),
because the red stripe on their bodies
is restricted to the tail region, rather than
extending all along the lower body. Females tend
to have plumper bodies than males, sometimes
causing their stripes to look more curved. As with
most other tetras, they are shoaling fish and will
thrive in groups, tending to occupy the midwater
region of the aquarium.

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