Goldfish - The Most Popular Pond Fish!
The Goldfish (Carassius
auratus auratus) was one of the earliest
fish to be
domesticated, and is still one of the most commonly kept aquarium
fish. A relatively small member of the carp family (which also
includes the Koi carp and the crucian carp), the goldfish is a
domesticated version of a dark-gray/olive/brown carp native to east
Asia (first domesticated in China that was introduced to Europe in
the late 17th century. The mutation that gave rise to the goldfish
is also known from other cyprinid species, such as common carp and
During the Tang
Dynasty, it was popular in China to raise carp in
ponds. As the result of a dominant genetic mutation,
one of these carp displayed "gold" (actually
yellowish orange) rather than silver coloration.
People began to breed the gold variety instead of
the silver variety, and began to display them in
small containers. The fish were not kept in the
containers permanently, but would be kept in a
larger body of water, such as a pond, and only for
special occasions at which guests were expected
would they be moved to the smaller container.
In 1162, the empress of
the Song Dynasty ordered the building of a pond to
collect the red and gold variety of those carp. By
this time, people outside the royal family were
forbidden to keep goldfish of the gold (yellow)
variety, yellow being the royal color. This probably
is the reason why there are more orange goldfish
than yellow goldfish, even though the latter are
genetically easier to breed.
As time passed, more
mutations occurred, producing new color variations,
and fancier varieties of goldfish were developed.
The occurrence of other colors was first recorded in
1276. The first occurrence of fancy tailed goldfish
was recorded in the Ming dynasty. In 1502, goldfish
were introduced to Japan, where the Ryukin and
Tosakin varieties were developed.
In 1611, goldfish were
introduced to Portugal and from there to other parts
of Europe. Goldfish were first introduced to North
America in 1874 and quickly became popular in the
Goldfish may grow to a
maximum length of 23 inches (59 cm) and a maximum weight of
9.9 pounds (4.5 kg), although this is rare; most individual goldfish
grow to under half this size. In optimal conditions, goldfish may
live more than 20 years (the world record is 49 years); however,
most household goldfish generally only live six to eight years.
Despite the illustrious
honor of being a carnival prize or swallowed on a dare, Goldfish (Carassius
auratus) are the most popular choice of fish for a water
garden. These fish are well suited for almost any pond size. The
unfortunate reputation that follows goldfish is that of the fish in
a bowl that dies in 2 days. Even in a small bowl (although not
recommended because of limited surface area) goldfish, if cared for,
can live many years.
Goldfish can be found in a
number of varieties and colors. Through selective breeding over the
centuries there are now many classified varieties of goldfish. The
list can extend into hundreds of individual varieties, below are
some of the most common...
Comet - The comet is generally the most common of
pond goldfish. It has a long slender body. This is often the typical
orange colored goldfish but can also be all white or white and red
(known as sarassa).
Shubunkin - The Shubunkin has an identical body
shape to the Comet. The difference is in the coloration. Shubunkins
should have a base color of light blue, which is covered with
patterns of darker blue, red, brown, white, or black.
Fantail - Another common pond fish is the Fantail.
Fantails are shorter and more plump than comets. Their caudal fin
(tail) is split giving them the fantail name. Basic Fantails can be
found in any goldfish colors (calico, sarassa, etc.).
Black Moor - The Black Moor has the body of a
fantail. As the name would imply this fish is solid black in color.
Its most distinguishing characteristic is the bulging of the eyes.
Ryukin - Ryukins are very similar to the basic
fantail. The primary difference is in the slope of the back. The
Ryukin has a sharp slope between the head and the dorsal fin.
Oranda - Orandas are also of fantail shape. Their
distinguishing feature is the headgrowth. The headgrowth is known as
the hood and has the appearance of being covered with warts.
Lionhead - The Lionhead is similar to the oranda in
that it has both the fantail shape and headgrowth. The difference in
this fish is that it completely lacks a dorsal fin.
Ranchu - Often confused with the lionhead the
difference lies only where the body meets the caudal fins. The
lionhead body extends straight out toward the caudal fin, while the
Ranchu body drops off sharply from the top of the back to the caudal
Bubble-Eye - The bubble-eye also has a shape
similar to a fantail. The distinguishing factor of this interesting
fish are the liquid-filled sacs that balloon out from below the eye
sockets. The eyes of the bubble-eye are also pointed upward.
Pearlscale - The Pearlscale is also shaped like the
common fantail. This fish gets its name from the dome-shaped scales
that cover the body. The raised parts of the scale are brighter and
have a pearly appearance.
Goldfish In Ponds
Goldfish are popular pond fish, since
they are small, inexpensive, colourful, and very hardy. In a pond,
they may even survive if brief periods of ice form on the surface,
as long as there is enough oxygen remaining in the water and the
pond does not freeze solid.
Common goldfish, London and Bristol
shubunkins, Jikin, Wakin, comet and sometimes fantail can be kept in
a pond all year round in temperate and subtropical climates. Moor,
veiltail, oranda and lionhead are only safe in the summer.
Small to large ponds are fine though
the depth should be at least 80 cm (30 in) to avoid freezing. During
winter, goldfish will become sluggish, stop eating, and often stay
on the bottom of the tank. This is completely normal; they will
become active again in the spring. A filter is important to clear
waste and keep the pond clean. Plants are essential as they act as
part of the filtration system, as well as a food source for the
fish. Plants are furthermore beneficial since they raise oxygen
levels in the water.
Compatible fish include rudd, tench,
orfe and koi, but the latter will require specialized care. Ramshorn
snails are helpful by eating any algae that grows in the pond. It is
of great importance to introduce fish that will consume excess
goldfish eggs in the pond, such as orfe. Without some form of
population control, goldfish ponds can easily become overstocked.
Koi may also interbreed to produce a sterile new fish.
Common flake fish food -
Like most fish, goldfish are opportunistic feeders and do not stop
eating of their own accord. When an excess of food is offered, they
will produce more waste and feces, partly due to incomplete
digestion of protein. Overfed fish can sometimes be recognized by
feces trailing from their cloaca. Goldfish need only be fed as much
food as they can consume in three to four minutes, and no more than
twice a day. Extreme overfeeding can be fatal, typically by bursting
of the intestines.
Special goldfish food has a
lower protein and higher carbohydrate content. It is sold in two
consistencies - flakes that float at the top of the aquarium, and
pellets that sink slowly to the bottom.
Goldfish enthusiasts will
supplement this diet with shelled peas (with outer skins removed),
blanched green leafy vegetables, and bloodworms. Young goldfish also
benefit from the addition of brine shrimp to their diet.
Behavior can vary widely
both because goldfish are housed in a variety of environments, and
because their behavior can be conditioned by their owners. A common
misconception that goldfish only have a three second memory is
completely false. Scientific studies done on the matter have shown
that goldfish have strong associative learning abilities, as well as
social learning skills. In addition, their strong visual acuity
allows them to distinguish between different humans. It is quite
possible that owners will notice the fish react favorably to them
(swimming to the front of the glass, swimming rapidly around the
tank, and going to the surface mouthing for food) while hiding when
other people approach the tank. Over time, goldfish should learn to
associate their owners and other humans with food, often "begging"
for food whenever their owners approach.
Goldfish also display a
range of social behaviors. When new fish are introduced to the tank,
aggressive social behaviors may sometimes be seen, such as chasing
the new fish, or fin nipping. These usually stop within a few days.
Fish that have been living together are often seen displaying
schooling behavior, as well as displaying the same types of feeding
Goldfish that have constant
visual contact with humans also seem to stop associating them as a
threat. After being kept in a tank for several weeks, it becomes
possible to "pet" a goldfish on the head, feed it by hand, or even
cup a hand around it without it reacting in a frightened manner.
Some goldfish have been trained to swim through mazes, push a ball
through a hoop, or even swim in a synchronized routine by their
Goldfish have behaviors,
both as groups and as individuals that stem from native carp
behavior. They are a generalist species with varied feeding,
breeding, and predators avoidance behaviors that contribute to their
success in the environment. As fish they can be described as
"friendly" towards each other, very rarely will a goldfish harm
another goldfish, nor do the males harm the females during breeding.
The only real threat that goldfish present to each other is in food
competition. Commons, comets, and other faster varieties can easily
eat all the food during a feeding before fancy varieties can reach
it. This can be a problem that leads to stunted growth or possible
starvation of fancier varieties when they are kept in a bond with
their single-tailed brethren.
Goldfish natively live in
ponds, and other slow or still moving bodies of water in depths up
to 20 m (65 ft). Their native climate is subtropical to tropical and
they live in freshwater with a pH of 6.0–8.0, a water hardness of
5.0–19.0 dGH, and a temperature range of 40 to 106 °F (4 to 41 °C)
although they will not survive long at the higher temperatures. They
are considered ill-suited even to live in a heated tropical fish
tank, as they are used to the greater amount of oxygen in unheated
tanks, and some believe that the heat burns them. However, goldfish
have been observed living for centuries in outdoor ponds in which
the temperature often spikes above 86 °F (30 °C). When found in
nature, the goldfish are actually an olive green color, and will
revert to this color if domesticated and then released. In the
wild, the diet consists of crustaceans, insects, and various plant
While it is true that
goldfish can survive in a fairly wide temperature range, the optimal
range for indoor fish is 68 to 75 °F (20 to 23 °C). Pet goldfish, as
with many other fish, will usually eat more food than it needs if
given, which can lead to fatal intestinal blockage. They are
omnivorous and do best with a wide variety of fresh vegetables and
fruit to supplement a flake or pellet diet staple.
Sudden changes in water
temperature can be fatal to any fish, including the goldfish. When
transferring a store-bought goldfish to a pond or a tank, the
temperature in the storage container should be equalized by leaving
it in the destination container for at least 20 minutes before
releasing the goldfish. In addition, some temperature changes might
simply be too great for even the hardy goldfish to adjust to. For
example, buying a goldfish in a store, where the water might be 70
°F (approximately 21 °C), and hoping to release it into your garden
pond at 40 °F (4 °C) will probably result in the death of the
goldfish, even if you use the slow immersion method just described.
A goldfish will need a lot more time, perhaps days or weeks, to
adjust to such a different temperature.
Because goldfish like to
eat live plants, their presence in an aquarium can be quite a
problem. Only a few of the aquarium plant species can survive in a
tank with goldfish, for example Cryptocoryne and Anubias
species, but they require special attention so that they are not
uprooted. Fake plants are often more durable, but the plant branches
can often irritate or harm a fish if it comes in contact with them.
Goldfish, like all
cyprinids, lay eggs. They produce adhesive eggs that attach to
aquatic vegetation. The eggs hatch within 48 to 72 hours, releasing
fry large enough to be described as appearing like "an eyelash with
two eyeballs". Within a week or so, the fry begin to look more like
a goldfish in shape, although it can take as much as a year before
they develop a mature goldfish color; until then they are a metallic
brown like their wild ancestors. In their first weeks of existence,
the fry grow remarkably fast - an adaptation born of the high risk
of getting devoured by the adult goldfish (or other fish and
insects) in their environment.
Goldfish can only grow to
sexual maturity if given enough water and the right nutrition.
However if kept well, they may breed indoors. Breeding usually
happens after a significant change in temperature, often in spring.
Eggs should then be separated into another tank, as the parents will
likely eat any of their young that they happen upon. Dense plants
such as Cabomba or Elodea or a spawning mop are used
to catch the eggs.
Most goldfish can and will
breed if left to themselves, particularly in pond settings. Males
chase the females around, bumping and nudging them in order to
prompt the females to release her eggs, which the males then
fertilize. Due to the strange shapes of some extreme modern bred
goldfish, certain types can no longer breed among themselves. In
these cases, a method of artificial breeding is used called "hand
stripping". This method keeps the breed going, but can be dangerous
and harmful to the fish if not done correctly.
Like some other popular
aquarium fish, such as the guppy, goldfish and other carp are
frequently added to stagnant bodies of water in order to reduce the
mosquito populations in some parts of the world, especially to
prevent the spread of West Nile Virus, which relies on mosquitoes to
migrate. However, the introduction of goldfish has often had
negative consequences for local ecosystems.
Edibility and Cruelty
Although edible, goldfish
are rarely eaten. A fad among American college students for many
years was swallowing goldfish as a stunt and as an initiation
process for fraternities. The first recorded instance was in 1939 at
Harvard University. The practice gradually fell out of
popularity over the course of several decades and is no longer
In many countries, the
operators of carnivals and fairs commonly give goldfish away in
plastic bags as prizes for winning games. In the United Kingdom, the
government proposed banning this practice as part of its Animal
Welfare Bill, though this has since been amended to only prevent
goldfish being given as prizes to unaccompanied minors.
However, in Rome, Italy, the city passed a law in late 2005, which
banned the use of goldfish or other animals as carnival prizes. Rome
has also banned the keeping of goldfish in "goldfish bowls", on the
premise that it's cruel to the fish to live in such a small,
Killing fish humanely for
human consumption or benign purposes (such as putting down an ill
fish) is still legal in most countries (provided that the fish is
not a protected fish caught in the wild, a fish in protected
reserves or in water where the person concerned has no right to
collect the fish). In the United Kingdom, it is illegal to sell live
fish (including goldfish) as "feeder fish" for consumption by other