The freshwater tropical aquarium system does not require any marine salt (however, some species, such as mollies, enjoy a teaspoon per 5 gallons added) and generally requires some type of heater. This type of system also usually contains live plants and has gravel for substrate.
If you are a beginner you will find valuable information in this article
Carnivore: Any organism that eats animals as the main portion of its diet
Herbivore: Any organism that eats plant material as the main portion of its diet.
Omnivore: Any organism that eats both plant and animal material as the main portion of its diet..’
Community tank: An aquarium where many different compatible species of fish are kept together.
The anabantids are a group of fish native to African and Asian waters. These fish have a specialized organ called a labyrinth that helps them breathe atmospheric air in the low-oxygenated waters of their native environment.
This doesn’t mean you should keep them in an aquarium that lacks aeration. If you do, your fish will eventually become ill due to poor water conditions. Anabantids are generally peaceful species that swim in the middle to upper
levels of the aquarium tank. They are easy to breed.
Climbing perch (Anabas testudineus)
This amazing fish can live several days without water, and has been known to travel across land in its native environment as it moves from pond to pond.
Keep climbing perch in water near 80 degrees F and provide plenty of shelter for them (rock caves and so on). This fish should be kept with its own kind. The climbing perch grows to 10 inches in length, is carnivorous, and swims in all
levels of the tank. A climbing perch requires a tank of at least 125 gallons and isa good choice once you have mastered a few of the easier-to-keep species.
Betta or Siamese fighting fish (Betta splendens)
The Asian Siamese fighting fish, also known as the betta, has been bred for years to develop strains that have long flowing fins and bright colors.
Males of this species are aggressive toward each other so you should only have one male per tank. You can keep Siamese fighting fish in a community aquarium as long as the other fish are not fin nippers.
Bettas build bubble nests by blowing air from their mouths in the form of bubbles that cling together in a mass. If you want to spawn them, they should be kept at a temperature of 76–83 degrees F. The betta is omnivorous and swims in all levels of the tank.
Bettas enjoy being fed floating foods and freeze-dried bloodworms. Remember that bettas are not a very active fish, so they will not eat as much as more robust varieties.
Cyprinodonts and livebearers
The cyprinodont group is also known as toothcarps because they have tiny teeth. This group contains both livebearing and egg-laying fish and contains some of the most popular and classic community fish (guppies, platys, and
swordtails). Cyprinodonts are friendly, easy to breed, and swim in all levels of the tank.
Although most killifish prefer soft, acidic water, a few species can be kept in a community aquarium. The killifish swims in the upper to middle levels of the tank and is carnivorous. Killifish should be kept in schools (three or more fish).
Medaka or rice fish (Oryzias latipes)
This species is native to China, Japan, and South Korea. Keep rice fish in a school (three or more fish) to ensure their survival in a community aquarium.
Rice fish prefer a well-planted tank and fertilize their eggs internally (the eggs hatch in 10–12 days.) This species has been known to jump out of a tank, so a tight-fitting hood is a must. The rice fish is carnivorous, requires live food, and swims in the upper level of the tank.
Rice fish enjoy a pH of 7.0 and a temperature of 64 –75 degrees F. They grow to an adult size of about 2 inches.
Striped panchax (Aplocheilus lineatus)
This great community fish is also an aquarium jumper, so make sure your aquarium hood is secure. This egg-laying species uses plants for shelter and to spawn, so provide plenty of plants. The panchax is carnivorous, requires live food, and swims in the upper level of the tank.
Guppy (Poecilia reticulata)
The Central American guppyis an amazing little fish. It has been the staple of many community aquariums since the hobby began. Guppies are now available in a wide variety of colors and fin shapes. Many hobbyists have started out by keeping guppies as aquatic friends.
Though often inexpensive, do not overlook the beauty of these little fish, because they can provide years of joy as you watch their very active lifestyle and mating rituals.
The guppy should be kept in water that has a temperature of between 78–82 degrees F. Guppies do best with one tablespoon of aquarium salt added for every 5 gallons of water. Guppies do well with flake food and are highly
appreciative of frozen brine shrimp as a treat.
Swordtail (Xiphophorus helleri)
The swordtail (native to Mexico, Honduras, and Guatemala) is a brightly colored fish that makes a good addition to any community aquarium.
The males of this species have an elongated caudal fin extension that resembles, not surprisingly, a sword. Male swordtails, like guppies, have a gonopodium (see the preceding “Guppy” section) and prefer heavily planted tanks.
Swordtails are very active and should be kept in water that is slightly hard (has high mineral content such as magnesium, calcium, and sulfates).
The water temperature should be kept between 78–82 degrees F. Like other livebearers, the swordtails
do well by having one tablespoon of aquarium salt added for every 5 gallons of water in the tank.
If you want to breed this fish, you should have a ratio of one male to three females for best results. Having more females helps to ensure that breeding will occur, and will keep the male from harassing one female constantly.
Swordtails can reach average lengths of up to 5 inches in captivity and will live 3–5 years in good water conditions.
Sailfin molly (Poecilia latipinna)
The sailfin molly is a beautiful species native to the brackish waters of the United States and Mexico. The male’s dorsal fin, when erect, looks like the sail on a ship. Keep mollies in a well-planted tank and provide extra vegetation in their diet.
This species can be aggressive toward smaller fish, but generally makes a great community membe
Mollies enjoy slightly salty water, so you can add about one teaspoon of salt for every 5 gallons of water to make them happy. Keep the water between 78–82 degrees. The sailfin molly is omnivorous and swims in all levels of the tank, and generally grows up to lengths of 4 inches during their 3–5-year lifetime.
We really like about all mollies in general is that they come in such an amazing variety of colors and patterns (marble, patches, metallic, tricolors, and so on). Their round bodies are cool to watch as they make their way through your aquarium.
Platy (Xiphophorus maculatus)
Platys sport some of the most beautiful colors of all freshwater fish. This hardy species, which is native to Mexico, Honduras, and Guatemala, breeds easily in the community aquarium and is very peaceful. Platys have been developed extensively through commercial breeding and can be found with different fin shapes and in almost every color imaginable.
The platy is omnivorous, swims in all levels of the tank, and is easy to breed.
.Keep your platys in the same salt conditions as the previously mentioned other livebearers and let them enjoy their water temperature in the 78–82degree F range as well. The platy will grow to 3 inches and live several years.
Catfish play an important role in the aquarium system. These species generally feed off the substrate as they gather unwanted debris.
Catfish often survive by using their barbels (specialized organs used for tasting) to locate the leftovers that fall to the bottom of the tank, but should be provided with a diet of sinking pellets as well.
Many species are nocturnal (more active at night), so feed them the sinking food formulated especially for them accordingly. Catfish can be aggressive if they are not kept with species their own size, and most are omnivorous.
Bristlenose catfish (Ancistrus temmincki)
The bristlenose catfish is a prehistoric-looking member of the Loricariidae family. Males of this species carry a double row of bristles on their snouts, whereas the females bear only a single row.
The bristlenose’s mouth is formed into a sucker disk that it uses to feed on algae in its native habitat.
This South American catfish is herbivorous, lives in the lower level of the aquarium, and is peaceful.
Glass catfish (Kryptopterus bicirrhis)
The glass catfish is a fascinating animal with a transparent body: You can actually see this fish’s backbone and internal organs through its body wall.
You can even see the food they have eaten before it is broken down, by looking through their body.
The glass catfish is carnivorous and swims in the middle and lower sections of the tank. Glass cats do not do well with many medications, so prevention is the key with this species.
The temperature of the water for glass catfish should be kept between 75–79 degrees F, and soft water with a pH between 6.2–7.0. This fish lives on insects in its native waters; so it should be fed a diet that includes live foods, such as daphnia.
Keep this fish in a group with its own kind because it is a schooling fish in the wild and will become very shy and inactive without others of its own type to keep it company. Never keep one alone without other glass catfish.
Upside-down catfish (Synodontis species)
True to its unusual name, the upside-down catfish swims with its abdomen pointed upward. This beautiful little fish from tropical Africa changes its body shading according to its swimming position. The peaceful upside-down catfish is carnivorous and swims in all levels of the tank.
This fish does well in temperatures between 72–79 degrees F and have been known to live more than five years.
Upside-down catfish grow to lengths of 3–4 inches in the home aquarium, have a forked tail and three sets of barbels, and should be kept in small schools.
The dorsal side of the fish is lighter in color, which (used for camouflage) is the complete opposite of most other species that swim in an upright direction. This fish usually has a beautiful mottled body in earth tones.
Suckermouth catfish (Hypostomus plecostomus)
One of the most famous catfish known to the aquarium hobbyist is the sucker-mouth. Hypostomus is also known as the pleco.
This fish has a leopard-print pattern of spots and can grow to a length of over one foot, so make sure you have plenty of space for this species to grow. This species can be slightly territorial, so good tankmates can include fish that can hold their own, such as larger cichlids.
Suckermouth catfish do well in temperatures between 69–79 degrees F and is very tolerant of most normal aquarium conditions. The suckermouth is herbivorous (it loves to remove algae from your aquarium) and swims in the lower and middle levels of the tank.
Cory (Corydoras species)
Probably the most popular species of catfish for the home aquarium is the cory. Corys come in a wide variety of spotted and striped patterns, are inexpensive, and do a good job cleaning debris (fallen food, dead plant leaves) from the bottom of the tank.
The friendly little blackfin cory from South America is one outstanding omnivorous member of this genus that swims in the lower levels.
Corys should be kept in schools (at least three) and are easily bred by amateurs. Females are larger and rounder than the males of the species.
They spend most of their time in search of food, so make sure you provide them will sinking pellet foods such as algae wafers. These fish can reach lengths of 2–3 inches on average in a home aquarium and have been known to live as long as ten years. Keep their water temperature between 72–78 degrees.