Discus | The discus is a species of tropical cichlid, found in the Amazon basin of South America. There are three recognised sub-species of the discus which are the green discus, the blue discus and the brown discus.
The discus was first described by Dr. Heckel in 1840 and despite
variations in colour, all are similar in appearance but are found in
different geographic locations. There is however some disagreement over
the scientific names for each species, but many agree that most captive
bred discus are thought to have originated from these three sub-species.
The discus is a medium sized fish, with a round, flattened body and large extended fins which also add to it's disk-like shape (from which it get it's name). Discus have small mouths and small bright red eyes, and vary in colour depending on the species (either green, blue or brown in the wild, but there are many new variations found in aquariums around the world today such as red). The round body of the discus also has nine dark, vertical stripes which are thought to be used both for camouflage (along with it's colour and flattened body) and to communicate within the school.
The discus is a medium sized fish, with a round, flattened body and large extended fins which also add to it's disk-like shape (from which it get it's name). Discus have small mouths and small bright red eyes, and vary in colour depending on the species (either green, blue or brown in the wild, but there are many new variations found in aquariums around the world today such as red). The round body of the discus also has nine dark, vertical stripes which are thought to be used both for camouflage (along with it's colour and flattened body) and to communicate within the school.
The discus is one of only a few cichlid
species found outside of Africa. They are found inhabiting sections of
deep, calm, well-wooded waters in the Amazon Basin and it's tributaries.
These slow-moving rivers and backwaters of the Amazon river system that
stretch through Brazil, Columbia and Peru, provide the perfect habitat
for these large fish, which generally shelter amongst the submerged
roots and branches. Discus are known to be fussy about the water
conditions in artificial habitats and are not for the inexperienced
keeper. In their natural environment, discus inhabit soft, acidic, and
very warm waters, where there is less competition from other fish.
Discus form pair bonds when they are about 75% of their adult size and
these pairs tend to remain together for life. They choose a nearly
vertical spawning site, which is then cleaned in preparation for the
female to lay between 80 and 400 eggs. The male then fertilises them and
both parents help to guard their eggs until they hatch. Like other
cichlids, discus parents care for their young well and even secrete a
slimy substance through their scales for their fry to feed off for the
first couple of weeks. Discus can live until they are between 10 and 15
years old but it is not uncommon for those kept in well-run artificial
habitats, to reach even older ages.
Like many other fish, discus will eat almost anything
that will fit in their mouths. Despite this, they have a predominately
meat-based diet that is high in protein. They mainly feed on small fish
and fry, along with larvae and other aquatic insects, and invertebrates such
as worms. They tend to eat relatively slowly, grazing through the
surrounding waters for tasty morsels. Those kept in captivity are also
commonly fed brine shrimp and bloodworm which are both protein-rich,
along with standard fish flakes (although this needs to be monitored to
avoid over feeding). Discus inhabit areas where there is plenty of
underwater debris for them to hide amongst. Their unique shape, colours
and markings also provide them with camouflage from approaching
predators in the Amazon river system. Larger species of fish, turtles
and other water-dwelling animals are the most common predators of the discus,
along with other predators such as bats and birds that hunt the discus
from the sky above. Discus populations across South America are also
threatened by habitat destruction, caused both by deforestation and
pollution of the surrounding water.
The discus today is an incredibly popular aquarium species and
it is thought to be one of the most written about tropical fish, over a
period of just 50 years. Although fish today are all thought to have
come from the green, brown and blue discus in the wild, others colours
are much more common in tanks including yellow, black and red. Today
there is a major industry behind the captive breeding of discus, which
primarily occurs in fish farms in a number of countries in Asia. They
are relatively peaceful fish, co-inhabiting their surroundings with
other, generally smaller fish that provide no competition for food.
Today, the discus is listed as a Threatened species in it's natural
habitat meaning that if the situation progresses unchanged, the discus
will be at threat from extinction in the wild in the near future.
Although many variations of discus occur in tanks around the world,
population numbers of the original discus species in the wild are
declining, primarily due to the decreasing quality of the surrounding
water.
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