Less than two inches when fully grown, this small rainbow is a truly beautiful fish that fits in well with other small shoaling fish in a well-planted community aquarium. Providing that this fish is transferred over to its new aquarium home slowly, they will adapt to a wide range of water conditions ranging from soft and slightly acidic water to hard and alkaline.
Origins and Distribution
Forktailed Rainbow Fish are native to Peria Creek,
Kwagira River, eastern Papua New Guinea, meaning that they are available in the
wild in only a very small geographic area in the Milne Bay province. They
occasionally travel into nearby rivers and tributaries, probably as a result of
drainage among the different waterways. These fish prefer slow-moving streams
lined with heavy vegetation; these environments make it easy for them to find
their favorite foods: zooplankton, phytoplankton, and invertebrates. Pseudomugil
furcatus usually mate within the shoal and lay their eggs
among feathery-leafed plants.
Today, very few Fork tailed Rainbow Fish are collected in
the wild. Because they are easy to breed, they are bred in captivity for the
Colors and Markings
The Forktailed Rainbow Fish or Pseudomugil furcatus is
a very attractive species with blue eyes, a silvery body, and bright
yellow stripes on the top and bottom of the body in the breeding season. Two
upturned almost wing-like pectoral fins, bright yellow in color along with
bright yellow dorsal fins in breeding season make this little gem a great
attrition to any Community Aquarium.
Forktailed Rainbow Fish are a shoaling species and should
be kept with between six and ten of their own kind. A generally peaceful fish,
they can live comfortably with smaller goby or catfish species, danios, tetras,
rasboras, dwarf cichlids, and other small rainbow fish. Do avoid keeping this
species in a tank with slower-moving fish or fish with long, trailing fins as
they do sometimes nip and can be a bit aggressive.
Forktailed Rainbow Fish Habitat and Care
When creating a habitat for your Forktailed Rainbow Fish,
remember that their native environment is slow-moving water with a great deal
of vegetation. To recreate a similar habitat, choose a 30 gallon or larger
aquarium and add a dark, fine, sandy or rocky substrate. Decorate with river
rocks, driftwoods, rooted plants, and floating feathery-leafed
plants. Floating plants and a dark substrate will not only bring out
their colors to best effect, but the fish will be more comfortable and calm,
with this touch of their natural environment added. Live plants are necessary
for this fish to thrive. Be sure the water is well oxygenated; to do this,
you'll need a good filtration system that doesn't create too much turbulence.
The Forktailed Rainbowfish is a very active fish, not
only fast but agile as well, swimming, twisting and turning in and out of
plants playfully all day. They are a middle zone fish and are in motion as
long as aquarium lights are on. It is best to keep 2 males and 4-6 females for
best and most active displays. Forktailed Rainbow Fish need plenty of time
to acclimatize to a new tank environment. Quick exposure to a different water
chemistry and temperature can shock their systems.
These fish are short-lived in nature, and because of this
they mature quickly, breed young and are over the hill by one year of
age. Males are prime at about 8 months, after 1 year to 15 months they
will develop a pigeon chest, at which time they are too old or mature to
breed. However many Forktailed Rainbow Fish live to be very old fish in a
community aquarium, just no longer prime for breeding.
Forktailed Rainbow Fish Diet
A great advantage of this kind of fish is their
feeding requirements: they have almost no special needs. Choose flake,
micropellets, and small frozen foods such as daphnia, baby brine shrimp (Artemia nauplii),
The males can be distinguished by their clearer colors
and the striking fin shape (curved and almost wing-like) which are bright
yellow. Females and juveniles have the same basic coloring as males, but the
colors are not as brilliant.
Breeding the Forktailed Rainbow Fish
Over the last 10 years, this remarkable member of the
Rainbow Fish family has faded almost completely from the Home Aquarium
scene. It is unfortunate, because not only is this remarkable fish one of
the easiest of the Rainbow Fish to keep in a community aquarium, it is also one
of the easiest of its kind to breed.
Pseudomugil furcatus is
easy to breed, beautifully colored and relatively hardy. They are not
fussy with regard to hardness or pH and seem to do well in a very wide range of
Best Breeding Procedure
Use 2 males and 6 females, each male will set up his own
“territory” in the well-planted breeding tank. One of the males will take
possession of a fine-leaved plant or breeding mop at a far end of the
tank. You will notice that the females will stay in the middle of the
aquarium during this mating ritual; the other male may take possession of
another plant of breeding mop at the other end of the tank.
You must get up at sunrise, or cause the lighting
system in the breeding tank to simulate dawn, for it is then that the males
will display for the females (worth getting up for, they become quite beautiful
in their dances). Occasionally the males may have a brief skirmish for
dominance, but they tend to ignore each other (this is why we suggest 6
Eventually, a female will follow one of the males back to
his chosen plant or breeding mop to spawn. You will know they are spawning
when they dip to the lower reaches of the tank and swim up into the plant or
mop close next to each other. As they reach close to the top of the plant,
they push into each other and release eggs and milt together.
The most difficult part about breeding this remarkable
fish is the wait for the eggs to hatch. It will take at least 14
days. There is a real chance of losing the eggs to fungus if left in the
breeding tank. Best results are had removing the eggs to a sterile water
tank, with fungus treatment.
Rearing the Fry
The fry (baby fish) are unusual among small egg layers in
that they are free swimming and self-sufficient at time of hatching. They
are large enough to accept live baby brine shrimp and powdered dry food.
Use a sponge filter in the fry rearing tank after 3
weeks, change 20% of the water each week, and feed small amounts of varying
foods 6 times a day. With luck and good attention to detail, the fish will
be sexable at 3 months and over an inch long.
By Thomas Reich