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Saturday 4 April 2015

FRESHWATER FISH & FISH TANKS


                                                         
                                                                                    .....its all about freshwater fish
                                                                                                                            & fish tanks.


Goldfish
The goldfish (Carassius auratus auratus) is a freshwater fish in the family Cyprinidae of order Cypriniformes. It was one of the earliestfish to be domesticated, and is 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 less-colorful carp (Carassius auratus) native to east Asia. It was first domesticated in China more than a thousand years ago, and several distinct breeds have since been developed. Goldfish breeds vary greatly in size, body shape, fin configuration and coloration (various combinations of white, yellow, orange, red, brown, and black are known).

History and evolution


Three goldfish from Fish Swimming Amid Falling Flowers, a Song dynastypainting by Liu Cai (c.1080–1120)

History

Starting in ancient China, various species of carp (collectively known as Asian carps) have been domesticated and reared as food fish for thousands of years. Some of these normally gray or silver species have a tendency to produce red, orange or yellow color mutations; this was first recorded during the Jin dynasty (265–420).[3][4]

An orange colored wild-caughtPrussian carp with goldfish-like coloration.
During the Tang dynasty (618–907), it was popular to raise carp in ornamental ponds andwatergardens. A natural genetic mutation produced gold (actually yellowish orange) rather than silver coloration. People began to breed the gold variety instead of the silver variety, keeping them in ponds or other bodies of water. On special occasions at which guests were expected they would be moved to a much smaller container for display.[5][6]
By the Song dynasty (960–1279), the domestication of goldfish was firmly established.[7] In 1162, the empress of the Song Dynastyordered the construction of a pond to collect the red and gold variety. By this time, people outside the imperial family were forbidden to keep goldfish of the gold (yellow) variety, yellow being the imperial color. This is probably the reason why there are more orange goldfish than yellow goldfish, even though the latter are genetically easier to breed.[8] The occurrence of other colors (apart from red and gold) was first recorded in 1276.
Add  A western aquarium of the 1850s of the type that contained
goldfish among other 
coldwater caption
During the  Mingdynasty (1368-1644), goldfish also began to be raised indoors, which led to thespeciesselection for mutations that would not be able to survive in ponds. The first occurrence of fancy-tailed goldfish was recorded in the Ming Dynasty. In 1603, goldfish were introduced to Japan. In 1611, goldfish were introduced to Portugal and from there to other parts of Europe.
During the 1620s, goldfish were highly regarded in southern Europe because of their metallic scales, and symbolized good luck and fortune. It became tradition for married men to give their wives a goldfish on their one-year anniversary, as a symbol for the prosperous years to come. This tradition quickly died, as goldfish became more available, losing their status. Goldfish were first introduced to North America around 1850 and quickly became popular in the United States.

Biology

Size

As of April 2008, the largest goldfish in the world was believed by the BBC to measure 19 inches (48 cm), and be living in the Netherlands.[13] At the time, a goldfish named "Goldie", kept as a pet in a tank in Folkestone, England, was measured as 15 inches (38 cm) and over 2 pounds (0.91 kg), and named as the second largest in the world behind the Netherlands fish.[13] The secretary of the Federation of British Aquatic Societies (FBAS) stated of Goldie's size that "I would think there are probably a few bigger goldfish that people don't think of as record holders, perhaps in ornamental lakes".[13] In July 2010, a goldfish measuring 16 inches (41 cm) and 5 pounds (2.3 kg) was caught in a pond inPoole, England, thought to have been abandoned there after outgrowing a tank.

Feeding

Dried food for Goldfish

In the wild, the diet of goldfish consists of crustaceansinsects, and various plant matter. Like most fish, they are opportunistic feeders and do not stop eating on their own accord. Overfeeding can be deleterious to their health, typically by blocking the intestines. This happens most often with selectively bred goldfish, which have a convoluted intestinal tract. When excess food is available, they produce more waste and faeces, partly due to incomplete protein digestion. Overfeeding can sometimes be diagnosed by observing faeces trailing from the fish's cloaca.

Goldfish-specific food has less protein and more carbohydrate than conventional fish food. Enthusiasts may supplement this diet with shelled peas (with outer skins removed), blanched green leafy vegetables, and bloodworms. Young goldfish benefit from the addition ofbrine shrimp to their diet. As with all animals, goldfish preferences vary.

Vision



Goldfish for sale in an aquarium

Goldfish vision is among the most studied of all vision in fishes.[15] Goldfish have four kinds of cone cells, which are respectively sensitive to different colors: red, green, blue and ultraviolet. The ability to distinguish between four different primary colors classifies them astetrachromats.[16]

Varieties of domesticated goldfish


Selective breeding over centuries has produced several color variations, some of them far removed from the "golden" color of the originally domesticated fish. There are also different body shapes, fin and eye configurations. Some extreme versions of the goldfish live only in aquariums—they are much less hardy than varieties closer to the "wild" original. However, some variations are hardier, such as the Shubunkin. Currently, there are about 300 breeds recognized in China.[4] The vast majority of goldfish breeds today originated from China.

Reproduction


Goldfish fry just hatched (Ryukin)
Goldfish may only grow to sexual maturity with enough water and the right nutrition. Most goldfish breed in captivity, particularly in pond settings. Breeding usually happens after a significant temperature change, often in spring. Males chase gravid female goldfish (females carrying eggs), and prompt them to release their eggs by bumping and nudging them.

Goldfish, like all cyprinids, are egg-layers. Their eggs are adhesive and attach to aquatic vegetation, typically dense plants such as Cabomba or Elodea or a spawning mop. The eggs hatch within 48 to 72 hours.

Goldfish eggs showing cell division
Within a week or so, the fry begins to assume its final shape, although a year may pass before they develop a mature goldfish color; until then they are a metallic brown like their wild ancestors. In their first weeks of life, the fry grow quickly—an adaptation born of the high risk of getting devoured by the adult goldfish (or other fish and insects) in their environment.[24]

Some highly bred goldfish can no longer breed naturally due to their altered shape. The artificial breeding method called "hand stripping" can assist nature, but can harm the fish if not done correctly. In captivity, adults mafiy also eat young that they encounter.

Anglefish

Freshwater angelfish belong to the Cichlidae family, and come in a variety of color forms, and fin lengths. Through selective breeding programs, both standard fin varieties as well as veil fin varieties are available in many different color forms.



Species


The currently recognized species in this genus are
:


Angelfish in the fishkeeping hobby

A group of Pterophyllum altum
Angelfish are one of the most commonly kept freshwater aquarium fish, as well as the most commonly kept cichlid. They are prized for their unique shape, color and behavior. It was not until the late 1920s to early 1930s that the angelfish was bred in captivity in the United States.

Species

The most commonly kept species in the aquarium is Pterophyllum scalare. Most of the individuals in the aquarium trade are captive-bred. Sometimes, captive-bred Pterophyllum altum is available. Pterophyllum leopoldi is the hardest to find in the trade.

Care

Angelfish are kept in a warm aquarium, ideally around 80°F (27°C). Though angelfish are members of the cichlid family, they are generally peaceful when not mating; however, the general rule "big fish eat little fish" applies.

Breeding

Pterophyllum couple spawning



P. scalare is relatively easy to breed in the aquarium, although one of the results of generations of inbreeding is that many breeds have almost completely lost their rearing instincts, resulting in the [citation needed] In addition, it is very difficult to accurately identify the gender of any individual until it is nearly ready to breed.
tendency of the parents to eat their young.


Angelfish pairs form long-term relationships where each individual will protect the other from threats and potential suitors. Upon the death or removal of one of the mated pair, breeders have experienced both the total refusal of the remaining mate to pair up with any other angelfish and successful breeding with subsequent mates.


Compatibility with other fish



In pet stores, the freshwater angelfish is typically placed in the semiaggressive category. Some tetras and barbs are compatible with angelfish, but ones small enough to fit in the mouth of the angelfish may be eaten. Generous portions of food should be available so the angelfish do not get hungry and turn on their tank mates.


Aquarium varieties



Most strains of angelfish available in the fishkeeping hobby are the result of many decades of selective breeding. For the most part, the original crosses of wild angelfish were not recorded and confusion between the various species of Pterophyllum, especially P. scalare and P. leopoldi, is common. This makes the origins of "domestic angelfish" unclear. Domestic strains are most likely a collection of genes resulting from more than one species of wild angelfish combined with the selection of mutations in domesticated lines over the last 60 or more years. The result of this is a domestic angelfish that is a true hybrid with little more than a superficial resemblance to wild Pterophyllum species. Much of the research into the known genetics of P. scalare is the result of the research of Dr. Joanne Norton, who published a series of 18 articles in Freshwater and Marine Aquarium Magazine


An adolescent silver angelfish


  • Silver (+/+): The silver angelfish most commonly resembles the wild form of angelfish, and is also referred to as "wild-type". It is not, however, caught in the wild and is considered domestic. The fish has a silver body with red eyes, and three vertical black stripes that can fade or darken depending on the mood of the fish.

  • Gold (g/g): The genetic trait for the gold angelfish is recessive, and causes a light golden body with a darker yellow or orange color on the crown of the fish. It does not have the vertical black stripes or the red eye seen in the wild angelfish.

  • Zebra (Z/+ or Z/Z): The zebra phenotype results in four to six vertical stripes on the fish that in other ways resembles a silver angelfish. It is a dominant mutation that exists at the same locus as the stripeless gene.

  • Black lace (D/+) or zebra lace (D/+ - Z/+): A silver or zebra with one copy of the dark gene results in very attractive lacing in the fins, considered by some to the most attractive of all angelfish varieties.

  • Smokey (Sm/+): A variety with a dark brownish grey back half and dark dorsal and anal fins

  • Chocolate (Sm/Sm): Homozygous for smokey with more of the dark pattern, sometimes only the head is silver

Halfblack veil angelfish - P. scalare

  • Halfblack (h/h): Silver with a black rear portion, halfblack can express along with some other color genes, but not all. The pattern may not develop or express if the fish are in stressful conditions.


Sunset blushing veil angelfish - P. scalare

  • Sunset blushing (g/g S/S): The sunset blushing has two genes of gold and two genes of stripeless. The upper half of the fish exhibits orange on the best specimens. The body is mostly white in color, and the fins are clear. The amount of orange showing on the fish can vary. On some, the body is a pinkish or tangerine color. The term blushing comes from the clear gill plates found on juveniles, with pinkish gills underneath.

Koi angelfish - P. scalare

  • Koi (Gm/Gm S/S) or (Gm/g S/S): The koi has a double or single gene of gold marble with a double gene of stripeless. Their expression of orange varies with stress levels. The black marbling varies from 5%-40% coverage.

  • Leopard (Sm/Sm Z/Z) or (Sm/Sm Z/+): Leopards are very popular fish when young, having spots over most of their bodies. Most of these spots grow closer together as adults, so they look like chocolates with dots.

  • Blue blushing (S/S): This wild-type angelfish has two stripeless genes. The body is actually grey with a bluish tint under the right light spectrum. An iridescent pigment develops as they age. This iridescence usually appears blue under most lighting.

  • Silver gold marble (Gm/+): A silver angel with a single gold marble gene, this is a co-dominant expression.
  • Ghost (S/+): Heterozygous for stripeless results in a mostly silver fish with just a stripe through the eye and tail. Sometimes, portions of the body stripes will express.
  • Gold marble (Gm/g or Gm/Gm)
Depending on whether the Gold Marble is single or double dose, the marbling will range from 5% to 40% coverage.
Marble angelfish 
  • Marble (M/+ or M/M or M/g or M/Gm): Marble expresses with much more black pattern than gold marble. The marbling varies from 50% to 95%.
  • Black hybrid (D/g or D/Gm): A cross of black with a gold, the result is black hybrids, a very vigorous black that may look brassy when young. This cross does not breed true.
Gold pearlscale angelfish 
  • Pearlscale (p/p): Pearlscale is a scale mutation, also called the "diamond" angelfish in some regions due to the gem-like iridiscence on its scales. The scales have a wrinkled, wavy look that reflects light to create a sparkling effect. Pearl develops slowly, starting at around 9 weeks of age. In can be inhibited by stressful conditions. It is recessive, requiring both parents to contribute the allele.
  • Black ghost (D/+ - S/+): Similar to a ghost, it has a darker appearance due to the dark gene, and very similar to a black lace without complete stripes. Ghosts generally have more iridescence than normal.
  • Albino (a/a): Albino removes dark pigments in most varieties. Some, like albino marble still have a little black remaining on a percentage of the fish. The eye pupils are pink as in all albino animals. The surrounding iris can be red or yellow depending on the variety.
Silver Dollar
Due to variations within species, your item may not look identical to the image provided.
QUICK STATS
Minimum Tank Size30 gallons
Care LevelEasy
TemperamentPeaceful
Water Conditions72-77° F, KH 4-8, pH 5.0-7.0
Max. Size6"
Color FormWhite
DietHerbivore
OriginCaptive-Bred
FamilyCharacidae

The round shape and silver color of its body lend the Silver Dollar a very appropriate name. With a maximum size of 6", they are perfect for the larger community aquarium. This hardy characin will be a great choice for the beginner to the expert aquarist.

Tank requirment
A tank of at least 30 gallons will be the ideal environment for this characin. Silver Dollars are a lively schooling fish and best kept in groups of three or more. Rocks, plants, and driftwood help mirror its natural habitat and will help to reduce stress on the fish, though plastic plants may be necessary due to their herbivorous nature. They do best in soft, slightly acidic water with high filtration.

Breeding
The Silver Dollar will breed occasionally in an aquarium setting and a hospital or "breeding tank" with clumps of floating plants to spawn between will be necessary. Slightly acidic water is best for optimal breeding habits. After the eggs are laid removing the parents will be necessary to reduce the number of lost fry.

Diet
Silver Dollars are herbivorous and thus need plenty of vegetable matter in their daily diet. Algae tablets, flake foods or any other suitable foods should be fed multiple times daily, keeping a close watch to make sure they are getting their share from more aggressive eaters such as barbs and tetras.



 Black Ghost



The black ghost knifefish (Apteronotus albifrons) is a tropical fish belonging to the ghost knifefish family (Apteronotidae). They originate in freshwater habitats in South America where ranging from Venezuela to the ParaguayParaná River, including the Amazon Basin.[1]They are popular in aquaria. The fish is all black except for two white rings on its tail, and a white blaze on its nose, which can occasionally extend into a stripe down its back. It moves mainly by undulating a long fin on its underside. It will grow to a maximum length of 50 cm (20 in).[1] It does not have scales.

Black ghost knife fish are nocturnal. They are a weakly electric fish which use an electric organ and receptors distributed over the length of their body in order to locate insect larvae.
QUICK STATS

Minimum Tank Size150 gallons
Care LevelModerate
TemperamentSemi-aggressive
Water Conditions73-80° F, KH 0-10, pH 6.5-7.0
Max. Size1' 6"
Color FormBlack
DietCarnivore
OriginSouth America
FamilyApteronotidae


The kind of EOD produced can be used to distinguish between two types of weakly electric fish: the pulse-type and the wave-type.[8] The black ghost knifefish are considered to be the latter type, because they can continuously generate EODs in small intervals. Wave-type EODs have a narrow power spectra, and can be heard as a tonal sound, where the discharge rate establishes the fundamental frequency.[6] By emitting its own continuous sinusoidal train of EODs, the fish can determine the presence of nearby objects by sensing perturbations in timing and amplitude of electric fields, an ability known as active electrolocation.[7] The particular organs used to sense the self-generated high-frequency EODs are tuberous electroreceptor organs. On the other hand, when low-frequency electric fields are generated by external sources instead of the fish itself, a different class of electroreceptor organs is used for this passive electrolocation, called ampullary organs. Therefore, the black ghost knifefish uses an active and a passive electrosystem, each with its own corresponding receptor organs.[2] The fish can also use a mechanosensory lateral line system, which detects water disturbances created by the motion of the fish's body.[9] As nocturnal hunters, the fish can rely on all three systems to navigate through dark environments and detect their prey.



Guppies


The guppy (Poecilia reticulata), also known as millionfish and rainbow fish,[1] is one of the world's most widely distributed tropical fish, and one of the most popular freshwater aquarium fish species. It is a member of the Poeciliidae family and, like all other members of the family, is live-bearing.[2] Guppies, whose natural range is in northeast South America, were introduced to many habitats and are now found all over the world. They are highly adaptable and thrive in many different environmental and ecological conditions.[3] Male guppies, which are smaller than females, have ornamental caudal and dorsal fins, while females are duller in colour. Wild guppies generally feed on a variety of food sources, including benthic algae and aquatic insect larvae. Guppies are used as a model organism in the field of ecology, evolution, and behavioural studies.

Distribution and habitat


Guppies are native to Antigua and BarbudaBarbadosBrazilGuyanaJamaica, the Netherlands AntillesTrinidad and Tobago, the U.S. Virgin Islands, and Venezuela.[6][7] However, guppies have been introduced to many different countries on every continent except Antarctica. Sometimes this has occurred accidentally, but most often as a means of mosquito control. The guppies were expected to eat the mosquito larvae and help slow the spread of malaria, but in many cases, these guppies have had a negative impact on native fish populations.[8] Field studies reveal that guppies have colonized almost every freshwater body accessible to them in their natural ranges, especially in the streams located near the coastal fringes of mainland South America. Although not typically found there, guppies also have tolerance to brackish water and have colonized some brackish habitats.[3] They tend to be more abundant in smaller streams and pools than in large, deep, or fast-flowing rivers

Description


Sexual polymorphism exhibited in the Trinidadian guppy (above male, below female)

Guppy breeds

Guppies exhibit sexual dimorphism. While wild-type females are grey in body color, males have splashes, spots, or stripes that can be any of a wide variety of colors.[10] The size of guppies vary, but males are typically 1.5–3.5 cm (0.6–1.4 in) long, while females are 3–6 cm (1.2–2.4 in) long.

A variety of guppy strains are produced by breeders through selective breeding, characterized by different colours, patterns, shapes, and sizes of fins, such as snakeskin and grass varieties. Many domestic strains have morphological traits that are very distinct from the wild-type antecedents. Males and females of many domestic strains usually have larger body size and are much more lavishly ornamented than their wild-type antecedents.[11]

Guppies have 23 pairs of chromosomes, including one pair of sex chromosomes, the same number as humans.[12] The genes responsible for male guppies' ornamentations are Y-chromosome linked and are heritable.

Life cycle


Two or three generations of guppies per year occur in the wild. Guppies are well developed and capable of independent existence without further parental care by the time they are born. Young guppies school together and perform antipredator tactics. Brood size is extremely variable, yet some consistent differences exist among populations depending on the predation level and other factors.[3] Females of matching body sizes tend to produce more numerous but smaller-sized offspring in high predation conditions. Female guppies first produce offspring at 10–20 weeks of age, and they continue to reproduce until 20–34 months of age. Male guppies mature in 7 weeks or less.[3] Total lifespan of guppies in the wild varies greatly, but it is typically around 2 years.[14] Variations in such life historic characteristics of guppies are observed in different populations, indicating that different evolutionary pressures exist.

Discus




.Symphysodon, colloquially known as discus, is a genus of cichlids native to the Amazon river basin. Due to their distinctive shape and bright colors, discus are popular as freshwater aquarium fish, and their aquaculture in several countries in Asia is a major industry. They are sometimes referred to as pompadour fish.


Species


There are currently three recognized species in this genus:




Location and habitat[edit]

A map of the range (orange shading) ofSymphysodon
Symphysodon species inhabit the margins of floodplain lakes and rivers in the Amazon Basin of lowlandAmazonia,[11] where it is part of the highly diverse Neotropical fish fauna.
The three species of Symphysodon have different geographic distributions. S. aequifasciatus occurs in the Rio Solimões, Rio Amazonas and the Río Putumayo-Içá in Brazil, Colombia and Peru. In contrast the distribution of S. discus appears to be limited to the lower reaches of the AbacaxisRio Negro and Trombetas rivers. S. tarzoo occurs upstream of Manaus in the western Amazon.





Malawi cichlids





Lake Malawi is one of the Great Rift Valley lakes on the African continent, and just like the other Great Rift Valley lakes it is famous for its rich wild life. Aquarists appreciate the myriad of different cichlid species than can be found in Lake Malawi. Lake Malawi is a 40,000 year old lake and a lot of the cichlid species have developed in Lake Malawi and can be found nowhere else in the world. Lake Malawi is a large lake and contains several different environments: the rocky shores, the sandy bottom and the large open water areas. Malawi cichlids are found in all these environments and they have developed to fit into each niche. When you keep Malawi cichlids in your aquarium it is therefore important that you know which niche they inhabit in Lake Malawi, since different cichlids will appreciate different set ups.

Lake Malawi is 560 kilometers long and 75 kilometers wide at the widest point, which gives it a total surface area of almost 30,000 square kilometers. Three different countries share Lake Malawi: Malawi, Tanzania and Mozambique. Lake Malawi is therefore known under several different names, including Lake Nyasa, Lake Niassa and Lake Nyassa. The old European name for Lake Malawi is Livingstone\'s Lake. Water enters Lake Malawi chiefly via the Ruhuhu and the Shire River is the major outlet.

Aquarists usually divide Malawi cichlids into two main groups: Mbuna cichlids and Peacock cichlids. Mbuna means rock-dweller in one of the local languages, and it is a very suitable name for these cichlids since they inhabit the shallow and rocky regions along the shores of Lake Malawi. Mbuna cichlids are also found around the shores of the islands in Lake Malawi. Mbuna cichlids will typically display a strong, pastel coloration. The male is more vividly colored than the female, but if you keep only female Mbuna cichlids in your aquarium the dominant female can start to display a more striking coloration. When two male Mbuna cichlids live near each other, the weakest one can dampen his colors and look more like a female in order to reduce aggression. You should never keep two male Mbuna cichlids in the same aquarium unless you have a very large aquarium where they each male can claim his own territory. It is important that create natural territorial borders when you decorate the aquarium and the males must be able to stay out of each others sight. Since Mbuna cichlids spend their lives among rocks, caves and crevices it comes as no surprise that they are cave breeders.


The Peacock cichlids are instead found in the open waters in Lake Malawi. In the wild, Mbuna cichlids and Peacock cichlids hardly ever meet each other and it is not advisable to house them in the same aquarium. The name Peacock is derived from the vibrant coloration displayed by the male Peacock cichlids. Female Peacock cichlids have a duller and more camouflaging coloration. Peacocks are often carnivores, but some of the species feed on zooplankton. Peacock cichlids are ovophile mouthbrooders, which means that they female Peacock cichlid will guard the eggs inside her mouth.


In Aquarium
Alligator Gar
Alligator garAtractosteus spatula, are ray-finned euryhaline fishes related to bowfin in the infraclass Holostei (ho'-las-te-i). The fossil record traces the existence of alligator gars back to the Early Cretaceous over a hundred million years ago. They are the largest in the gar family, and among the largest freshwater fishes in North America. Gars are often referred to as "primitive fishes", or "living fossils" because they have retained some morphological characters of their earliest ancestors, such as a spiral valve intestine which is also common to the digestive system of sharks, and they can breathe both air and water. Their common name was derived from their resemblance to American alligators, particularly their broad snout and long sharp teeth. Anecdotal scientific reports suggest that alligator gars can grow up to 10 ft (3.0 m) in length and weigh as much as 300 lb (140 kg); however in 2011 the largest alligator gar ever caught and officially recorded was 8 ft 5 14 in (2.572 m) long, weighed 327 lb (148 kg), and was 47 in (120 cm) around the girth. Their bodies are torpedo shaped, usually brown or olive fading to a lighter gray or yellow ventral surface. They do not have scales like other fishes, rather they are armored for protection against predation with hard, enamel-like, jagged diamond-shaped ganoid scalesthat are nearly impenetrable. Unlike other gar species, mature alligator gars have a dual row of large sharp teeth in the upper jaw which they use for impaling and holding prey. They are stalking, ambush predators that are primarily piscivores, but will also ambush and eat water fowl and small mammals that may be floating on the surface.

Habitat

Alligator gars have been extirpated from much of their historic range through habitat destruction, indiscriminate culling, and unrestricted harvests. Populations are now located primarily in the southern portions of the United States extending into Mexico. They are considered euryhaline because they can adapt to varying salinities ranging from freshwater lakes and swamps to brackish marshes,estuaries, and bays along the Gulf of Mexico.



Arowana

Arowanas are freshwater bony fish of the family Osteoglossidae, also known as bonytongues[1] (the latter name is now often reserved for Arapaimidae).[2] In this family of fish, the head is bony and the elongated body is covered by large, heavy scales, with a mosaic pattern of canals. The dorsal and anal fins have soft rays and are long based, while the pectoral and ventral fins are small. The name "bonytongues" is derived from a toothed bone on the floor of the mouth, the "tongue", equipped with teeth that bite against teeth on the roof of the mouth. The arowana is a facultative air breather and can obtain oxygen from air by sucking it into its swim bladder, which is lined with capillaries like lung tissue.[3]

Evolution

Osteoglossids are basal (primitive) fish from the lower Tertiary and are placed in the actinopterygiid order Osteoglossiformes. As traditionally defined, the family includes several extant species from South America, one from Africa, several from Asia, and two fromAustralia.[1] Today Arapaimidae is often regarded as a separate family, which includes the arapaimas and the African arowana.[2]Consequently, the South American genus Osteoglossum, and the Asian and Australian genus Scleropages are the only extant genera that remain in the osteoglossid family.[4] Arapaimidae and Osteoglossidae split about 220 million years ago (Mya), during the Late Triassic.[5]
Within Osteoglossidae, the South America Osteoglossum arowanas diverged from the Asian and Australian Scleropages arowanas about 170 Mya, during the Middle Jurassic.
The Osteoglossidae are the only exclusively freshwater fish family found on both sides of the Wallace Line.[6] This may be explained by the theory that Asian arowanas (S. formosus) diverged from the Australian ScleropagesS. jardinii and S. leichardti, about 140 Mya, making it likely that Asian arowanas were carried to Asia on the Indian subcontinent.[7][5]

Fossil record

At least five extinct genera, known only from fossils, are classified as osteoglossids; these date back at least as far as the Late Cretaceous. Other fossils from as far back as theLate Jurassic or Early Cretaceous are widely considered to belong to the arowana superorder Osteoglossomorpha. Osteoglossomorph fossils have been found on all continents except Antarctica.[8] These fossil genera include BrychaetusJoffrichthys, and Phareodus.

Behavior

Osteoglossids are carnivorous, often being specialized surface feeders. They are excellent jumpers; Osteoglossum species have been seen leaping more than 6 ft (almost 2 m) from the water surface to pick off insects and birds from overhanging branches in South America, hence the nickname "water monkeys". Arowana species typically grow to around 2 to 3 ft in captivity.
Several species of osteoglossids exhibit parental care. They build nests and protect their young after they hatch. All species are mouthbrooders, the parents holding sometimes hundreds of eggs in their mouths. The young may make several tentative trips outside the parent's mouth to investigate the surroundings before leaving permanently


Arowana Feeding info

Arowana prefer live food or at the very least floating food. They will not generally eat from the bottom of the tank. To this end keeping your arowana with a suitable bottom feeder may be a good idea to prevent the buildup of detritus in the tank.

Appropriate foods can range from:

Mealworms, crickets, grasshoppers, locus, garden worms, fly, small frogs, small fish, shrimps, beef heart, etc.

The food your arowana will like is very personal to the fish, so try lots of different things and see how they respond.

Some food help to promote colour in your fish. Any food that contains ceratanoids will help develop red and gold colouring in your fish. However, it is recommended to always maintain a varied diet in your fish.

You can also feed live food on material high in ceratanoids, i.e feed carrots or shrimp to mealworms and then the mealworms to the Arowana.

Feeding patterns effect both the size and colour of your Arowana. Overfeeding can make the fish grow faster but can adversely affect both the colour and the long term health of the fish. Since the size, colour and health is very important do not regularly overfeed any Arowana.

For small fish feeding once or twice a day until they lose interest is enough. From six to 12 inches, once per day is enough. Beyond 12 inches you can consider once every two days, or even less.

High protein foods are also often low in nutrients. Food such as Mealworms are similar to crisps for humans. They taste great but do not have high nutritional value, they provide ideal variety but are a poor stable food.

The best food is fresh fish from your local fish market cut into cubes. You may have to starve the fish for up to several weeks in order to train them to eat food that is not live. If you feed live fish then make sure they are properly quarantined and disinfected before feeding them to your Arowana. Other fish are generally more susceptible to parasites which can in turn damage or kill your Arowana.


Oscar
Astronotus ocellatus is a species of fish from the cichlid family known under a variety of common names including oscartiger oscarvelvet cichlid, or marble cichlid.[1] In South America, where the species naturally resides, A. ocellatus specimens are often found for sale as a food fish in the local markets.[2][3] The fish introduced to other areas, including China, Australia, and the United States. It is considered a popular aquarium fish in the U.S

Taxonomy

The species was originally described by Louis Agassiz in 1831 as Lobotes ocellatus, as he mistakenly believed the species was marine; later work assigned the species to the genus Astronotus.[7] The species also has a number of junior synonyms: Acara compressus, Acara hyposticta, Astronotus ocellatus zebra, and Astronotus orbiculatus.

Description

Ocelli on dorsal fin and caudal peduncle
A. ocellatus examples have been reported to grow to about 45 cm (18 in) in length and 1.6 kilograms (3.5 lb) in weight.[1] The wild-caught forms of the species are typically darkly coloured with yellow-ringed spots or ocelli on the caudal peduncle and on the dorsal fin.[5] These ocelli have been suggested to function to limit fin-nipping by piranha (Serrasalmus spp.), which co-occur with A. ocellatus in its natural environment.[7][9] The species is also able to rapidly alter its colouration, a trait which facilitates ritualised territorial and combat behaviours amongst conspecifics.[10] Juvenile oscars have a different colouration from adults, and are striped with white and orange wavy bands and have spotted heads.

Distribution and habitat

Two tiger oscars
A. ocellatus is native to PeruEcuadorColombiaBrazil, and French Guiana, and occurs in the Amazon River basin, along the Amazonas, IçáNegroSolimões, and Ucayali River systems, and also in the Approuague and Oyapock River drainages.[1][2] In its natural environment, the species typically occurs in slow-moving white-water habitats, and has been observed sheltering under submerged branches.[5] Feral populations also occur in China,[11] northernAustralia,[12] and Florida, USA[13] as a byproduct of the ornamental fish trade. The species is limited in its distribution by its intolerance of cooler water temperatures, the lower lethal limit for the species is 12.9°C (55.22°F).

Reproduction

Although the species is widely regarded as sexually monomorphic,[5] males have been suggested to grow more quickly,[citation needed] and in some naturally occurring strains, males are noted to possess dark blotches on the base of their dorsal fins.[6][7] The species reaches sexual maturity around one year of age,[citation needed] and continues to reproduce for 9-10 years.[citation needed] Frequency and timing of spawning may be related to the occurrence of rain.[15] A. ocellatus fish are biparental substrate spawners, though detailed information regarding their reproduction in the wild is scarce.
Young oscar, about 2 in
In captivity, pairs are known to select and clean generally flattened horizontal or vertical surfaces on which to lay their 1,000 to 3,000 eggs.[citation needed] Like most cichlids, A. ocellatus practices brood care, although the duration of brood care in the wild remains unknown.

Territorial behavior

An albino oscar
Oscars will often lay claim to an area of the aquarium and will be very aggressive towards other fish encroaching on their newly establishedterritory inside the aquarium or lake. The size of the territory varies depending on the size and aggressiveness of the fish based on its surroundings. Once the oscar establishes a territory, it will vigorously defend it by chasing away other fish.[21]

Varieties



leucistic long-finned oscar
A number of ornamental varieties of A. ocellatus have been developed for the aquarium industry. These include forms with greater intensity and quantities of red marbling across the body, albinoleucistic, andxanthistic forms. A. ocellatus with marbled patches of red pigmentation are sold as red tiger oscars, while those strains with mainly red colouration of the flanks are frequently sold under the trade name of red oscars.[22] The patterning of red pigment differs between individuals; in the United Kingdom, one A. ocellatus reportedly had markings that resembled the Arabic word for "Allah".[23] In recent years long-finned varieties have also been developed. The species is also occasionally artificially coloured by a process known as painting.


Neon Tetra

The neon tetra (Paracheirodon innesi) is a freshwater fish of the characin family (family Characidae) of order Characiformes. The type species of its genus, it is native to blackwater or clearwater streams in southeastern Colombia, eastern Peru, and western Brazil, including the tributaries of the Solimões where the water is between 20 and 26 °C (68 and 79 °F).[2] It is not found in the whitewater rivers ofAndean origin. Its bright colouring makes the fish visible to conspecifics in the dark blackwater streams,[3] and is also the main reason for its popularity among tropical fish hobbyists.
Neon tetra
Neonsalmler Paracheirodon innesi.jpg
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Characiformes
Family:Characidae
Genus:Paracheirodon
Species:P. innesi
Binomial name
Paracheirodon innesi
(G. S. Myers, 1936) [1]

Description

The neon tetra has a light-blue back over a silver-white abdomen. The fish is characterized by an iridescent blue horizontal stripe along each side of the fish from its nose to the base of the adipose fin, and an iridescent red stripe that begins at the middle of the body and extends posteriorly to the base of the caudal fin. Rarely, they develop an olive-green sheen lining on their backs. The fish is completely transparent (including fins) except for these markings. During the night, the blue and red become gray or black as the fish rests—it reactivates once it becomes active in the morning. It grows to approximately 3 cm (1.2 in) in overall length. Sexual dimorphism is slight, with the female having a slightly larger belly, and a bent iridescent stripe rather than the male's straight stripe. They have recently become available in a long-fin variety.

In the aquarium


A community of neon tetras in a home aquarium
While commercially bred neon tetras have adapted well to a wide range of water conditions, in the wild they inhabit very soft, acidic waters that are usually cooler than the 25 °C (77 °F) at which most tropical aquaria are maintained.[2] They can have a lifespan of up to ten years, or normally about five in an aquarium.
Neon tetras reach 4 cm in length, and are considered easy to keep in a community aquarium of at least 50 cm (20 in) long,[citation needed]with a pH of 6.0 to 6.5 and a KH of 1.0 to 2.0. However, they will die if traumatized by dramatic changes to their environments. They tend to be timid and, because of their small size, should not be kept with large or aggressive fish which may bully or simply eat them. Fish that mix well in an aquarium are guppies, other types of tetras, such as the rummy-nose tetracardinal tetra, and glowlight tetra, and other community fish that live well in an ideal tetra water condition. Mid-level feeders, they are best kept in schools of six or more, for theshoaling effect when they move around the tank. They shoal naturally in the wild and are thus more brightly colored and more active when kept as a shoal as opposed to singly. The color and the iridescent stripe of this fish may become dim at night, and can be virtually invisible after a period of darkness. The color may also fade during a period of stress, such as human intervention into the tank. Neons are best kept in a densely planted tank with subdued light and an ideal temperature of 21–27 °C (70–81 °F) to resemble their native Amazon environments.
  1. Nutrition

    Neon tetras are omnivores and will accept most flake foods, if sufficiently small, but should also have some small foods such as brine shrimpdaphnia, freeze-dried bloodworms,tubifex, which can be stuck to the side of the aquarium, and micropellet food to supplement their diets. A tropical sinking pellet is ideal, as most brands of these include natural color enhancers that bring out the color in neon tetras. Some frozen foods, including frozen blood worms, add variety to their diets.

  2. Disease

    Neon tetras are occasionally afflicted by the so-called "neon tetra disease" (NTD) or pleistophora disease, a sporozoan disease caused by Pleistophora hyphessobryconis. Despite being a well-known condition, it is currently incurable and often fatal to the fish. The disease cycle begins when microsporidian parasite spores enter the fish after it consumes infected material, such as the bodies of a dead fish, or live food such as tubifex, which may serve as intermediate hosts. The disease is most likely passed by newly acquired fish, which have not been quarantined.
    Symptoms include restlessness, loss of coloration, lumps on the body as cysts develop, difficulty swimming, curved spines as the disease progresses, and secondary infections, such as fin rot and bloating.
    A so-called "false neon disease", which is bacterial, shows very similar symptoms. It is impossible for the home aquarist to determine for certain the difference between NTD and false NTD on the basis of visible symptoms alone, without laboratory backup. This disease has also been confused with columnaris (mouth rot, mouth fungus, 'flex').
    To date, no cure is known; the only 'treatment' is the immediate removal of diseased fish to preserve the remaining fish. The use of a diatom filter, which can reduce the number of free parasites in the water, may help.

  3. The blue acara

    1.  (Andinoacara pulcher[1] is a very colorful freshwater fish in the cichlid family. This fish can be found in Central and South America, from Panama to Colombia. They can reach lengths of 20 cm (7.9 in). The name Andinoacara pulcher is indicative to its looks;pulcher meaning "beautiful" The blue acara is a common cichlid sold in many pet stores, and is often confused with or sold as a green terror (Andinoacara rivulatus)
    2. The body is stocky and compact with a steel blue-gray coloration. Noticeable horizontal green lines occur on their faces and their blueish-green scales give them a sparkling appearance. They also have long, flowing fins with a hint of orange to the tips.
      Blue acaras natively live in a tropical climate and prefer water with a pH of 6.5-8.0, a water hardness of 25° dGH, and a water temperature of 22–30 °C (72–86 °F).
  4. Description

    The blue acara normally grows to around 13 cm, but has been scientifically measured at 16.0 cm (6.3 in). The body is compact and stocky, while the fins are long and flowing, with a rounder head than on similar cichlids.
    The main body colour can vary from browns to blues to black due to local diversity. The body is decorated with five to eight vertical black stripes (which may not always be distinctly visible) and blue iridescent spots, and the face sports a few horizontal green lines. The fins have a hint of orange on the tips and some specimens have a red topfin rim. A distinctive black line is present going from the eye down the cheek; this one line is not found on other similar cichlids.

    Taxonomy

    Formally Aequidens pulcher, this fish was suggested to be reclassified in 2012 during the study of Andinoacara rivulatus Stalsbergi and the recently discovered Andinoacara bloombergi.[4] The fish was included into the Andinoacara genus due to the genetic similarity with the new family.

    Distribution and habitat

    The blue acara lives in South and Central America, south to Trinidad and Tobago, Colombia, and Venezuela. The species can be found in both clear and turbid flowing streams