Rasboras or Rasbora
heteromorpha are members of
the family Cyprinidae.
Rasboras are native to Malaysia, Singapore, Sumatra, and
southern Thailand. There are several species in the genus Rasbora. We
will focus our attention on R. Heteromorpha. The Greek translation of
Heteromorpha literally means differently shaped.
referred to as harlequin fish or harlequin
rasboras. This reference alludes to the
black triangular patch on the
back half of their bodies which is reminiscent to the patterns found on
the costume of a harlequin.
temperament. They make a good choice for a
community tank provided their tank-mates are equally peace loving and
not large enough to view them as a source of nutrition. Rasboras are
shoaling fish. Shoaling fish are highly social creatures that function
best as a community. They don’t adapt well to a solitary
is recommended that you have at least four of these upper to mid tank
swimmers in an aquarium.
Rasbora is a
They only grow to an adult size of
1.5-1.75 inches. They thrive it soft, slightly acid water with a pH 0f
6.8 and a water temperature ranging between 74-78 °F. Under
conditions you can expect them to live up to 10 years of age.
They will survive just fine on a diet of common tropical fish flakes.
rasbora is relatively easy. The male bodies
are thinner. Females are more full bodied especially when carrying
eggs. The distinct triangular marking on the rear of their bodies
differs between sexes. The males have more defined angular markings
that extend further back on the lower abdomen than the females.
they inhabit streams that are littered
with jungle decay. As a result peat grows abundantly in the streams
releasing humic acid into the water. These same conditions can be
simulated by filtering the breeding tank’s water through peat
a thin layer of peat to the substrate. This will naturally increase the
acid levels in the water. Make certain the peat contains no chemical
additives or fertilizers.
A high protein
brine shrimp, tubifex or bloodworms will
help induce the spawning cycle. Provide plenty of plant life to
replicate their natural spawning grounds.
The male will
chasing the male as a manner of courtship. Once
the courtship phase is over the pair will spawn amid the foliage. Their
eggs will be deposited on the underside of a broad leaf. Remove the
adult from the breeding tank.
you will want to darken the tank. The fry are susceptible to fungal
Surround the with paper or tin foil until the fry hatch and are free
swimming. Eggs will hatch in about a day. After they hatch check the
tank once a day. When you see the fry are free swimming it is time to
start feeding them. This should take no longer than 3 days or so.
fry can be
fed liquid fry food formulated for egg
layers or newly hatched brine shrimp. An economical and readily
available alternative is powdered eggs. Make sure not to put too much
in the water to avoid clouding it up.
For Future Reference.