Power Filter

Power filters come in a wide variety of sizes and usually have one or two slots that hold fiber pads containing a small amount of activated carbon. They offer major advantages. The equipment and replacement pads are inexpensive. Changing the pads is quick and simple on most models.

The simplest power filters hang on the back of the tank. Water enters through a siphon that extends nearly to the bottom of the aquarium. An electric pump pulls water through the filter pads and returns it to the tank via a spillway.

Choose a model that accepts two filter pads and change only one at a time. This way, you do not throw away all your beneficial nitrifying bacteria each time you toss out a pad.

Corner Box Filter

One of the oldest devices in the aquarium hobby, the corner box filter was originally designed for small aquariums. This filter contains a single airstone attached to a pump that pushes water through layers of activated charcoal and floss contained in a plastic box. The filter itself rests on the gravel bed inside the tank.

Corner filters are inefficient because they take a long time to filter all the water in the tank. They can also be noisy and may float around the tank if they are not weighted down properly. A more efficient power filter is a better choice.

Aquarium Monitoring Water Conditions

During the conditioning period, monitor the nitrite level daily. Initially, no nitrite will be present. As the ammonia-converting bacteria begin to multiply, the nitrite level will rise as ammonia is converted. Within a couple of weeks to a month, the nitrite level will peak and then begin to decline. This event signals the development of nitrite-converting bacteria, which grow more slowly than the ammonia-converters. As nitrite becomes nitrate, you will observe a precipitous decline in nitrite. When the level of nitrite reaches zero, the conditioning process is complete.

A check of the nitrate level at this point will reveal that the level, originally zero, has now risen considerably.

Aquarium Conditioning Time

Conditioning time varies depending on the temperature of the water and the type and number of filtration units used. This period may take anywhere from three weeks to several months. The process will begin only after your starter fish have been introduced into the tank. A few hardy species, such as Guppies or a single Betta, should be added to the new aquarium to start the conditioning of the biological filter.

Ammonia levels begin to peak within seven to fourteen days, and eventually the helpful bacteria increase in numbers to detoxify the ammonia into nitrites. Next, the nitrites will accumulate to higher levels and other types of bacteria will begin to convert them to nitrates. Eventually, nitrite levels drop and the conditioning period ends. Nitrate levels will continue to slowly increase over time, but can be maintained at proper levels through frequent water changes.

Aquarium Water Hardness

The dH (degree of hardness) is simply the amount of dissolved mineral salts in the aquarium water. You can check the hardness of your tap water with a simple aquarium test kit. Bettas prefer soft water with a dH of less than 25. One way to dilute hardness is to add distilled water from the grocery store. Reverse osmosis units will also reduce hardness, but they are expensive and use a lot of tap water to produce a small amount of mineral-free water. Consider using one only if you need to soften a lot of water.

Aquarium Chlorine

City water departments add chlorine and chloramine to drinking water to eliminate harmful bacteria and to make it safe for human consumption. However, these chemicals can be deadly to your aquarium fish and must be removed. Bottled chlorine remover, which you can buy at your local aquarium shop, will neutralize the chlorine and chloramine in your tap water. Simply follow the label’s directions and add the chemical to the water before any fish or live plants are put into the aquarium.

are put into the aquarium. Another way to remove chlorine is to aerate the water for 12 hours or let it sit in open buckets for 48 hours. However, bottled chlorine remover works in seconds.

Aquarium Tubing

Aquarium tubing made of silicone/rubber material is easy to work with. Tinted blue-green by the manufacturer, it blends in nicely, virtually disappearing under water. Rubber tubing can be bent around decorations without kinking and does not crack with age. To slide tubing easily onto the pump outlet or the stem of an airstone, hold it briefly under very hot tap water to soften it slightly. It returns to normal when it cools.

Aquarium Airstones

Airstones increase oxygenation in the water by dispersing the air supplied by the pump. Aquarium dealers sell airstones made of wood, plastic, and ceramics. Depending upon the material, airstones require replacement every few months.

Aquarium Air Pumps

Inexpensive air pumps can be found in any aquarium shop. Your air pump should sit above the aquarium, if possible, to avoid any backflow of water if the power is shut off. You may want to get a valve to control the air flow. Placing a single valve in line with the pump restricts the flow, but it also makes the pump work harder. It may become noisy and will require more frequent replacement. Instead, use a dual valve. Connect one to the airstone in the tank and use the other to bleed off excess air pressure into the atmosphere.

Aquarium Rocks

Aquarium supply stores sell a variety of tank decorations that enhance the habitat for your fish. Some are plastic or ceramic creations and others are simply attractive rocks and stones. By buying these tank decorations from the dealer, you are avoiding contaminating your tank with toxic substances and water chemistry-modifying agents. Avoid the temptation to collect your own rocks until you know how to identify each kind and its influence on your aquarium.

If you add rocks to your aquarium, place them so they won’t topple. Never lean rocks up against the side of the tank for support, because they can fall and injure your Betta or break the glass. Smooth, waterworn stones look natural in the aquarium; angular blocks do not. In addition, smooth stones don’t have sharp, rough edges that could hurt your fish.

One way to create a permanent and safe effect is to glue rocks together using a silicone aquarium sealer. This will keep your rock display in place if burrowing bottom dwellers begin to dig around them. Always allow the sealer to dry for several days before you place the assembly in the aquarium.

Aquarium Siphons

Siphoning unwanted debris from the tank is a regular part of good maintenance. The siphon can be simply a length of plastic hose. Place one end in the water and the other in a bucket on the floor. Suck on the lower end to start water flowing. Hobbyists squeamish about this procedure will find self-starting and even electrically powered siphons in their local aquarium shop.

A handy accessory for cleaning the gravel bed consists of a long funnel, wider in diameter than the hose, attached to the intake end of the siphon. This design enables water and fine debris to be siphoned out, while leaving heavier gravel or sand on the bottom. I find this gadget to be a good investment.

Change some water and siphon out debris once a week and your tank will remain sparkling clean and healthy. Some hobbyists like to do a larger water change and more thorough vacuuming every month, as well. Choose a routine that suits your schedule and stick with it.

Aquarium Scrapers

A scraper is a great tool that can be used to remove algae from the aquarium glass. Most scrapers come with a two-sided head. One side has a soft sponge for wiping away loose algae. The other side of the scraper contains a tough scrub pad for removing encrusted algae and lime deposits. Most scrapers are made of plastic and have a long handle for reaching difficult spots in the aquarium. The other end of this tool looks like a small fork and is great for turning over gravel and planting.

Aquarium Nets

Nets are available in a variety of sizes and designs. Smaller nets are generally used for catching fry and little fish. The fine webbing in these nets is soft and similar in structure to cheesecloth. Small nets are also handy for scooping out uneaten food and suspended debris from the water.

Larger nets are usually used for capturing fish. You will find that using two large nets to capture a Betta is much easier than trying to do the job with only one. Your fish can easily be coaxed into the center of one net by gently nudging it with the other. You should buy several nets of different sizes so that you will be prepared to handle almost any task.

Aquarium Covers and Light Hoods

Aquarium dealers supply two types of lighting arrangements. The simplest includes a glass cover that fits into a lip molded into the plastic trim at the top of the tank. Across this, a long, narrow plastic fixture, called a strip light, holds one or two fluorescent bulbs.

The more elaborate arrangement, called a hood, completely covers the top of the tank. Lighting equipment is mounted inside the hood. Metal halide units and larger fluorescent units should have a ventilation fan to prevent overheating. Dealers offer hoods designed to match the aquarium. Choosing such an ensemble lends a finished, professional look to the tank, making it blend in well with home décor.

Aquarium Metal Halide Lights

Metal halide lights provide plenty of intensity for vigorous plant growth and produce a pleasing visual effect in the aquarium. On the downside, they produce a lot of heat and are expensive compared to a fluorescent system. For a large tank with sun-loving plant varieties, though, metal halide lighting should be your first choice.

Aquarium Fluorescent Bulbs

Fluorescent lighting is the best choice for the Betta aquarium. It fosters plant growth, has a long lamp life, and does not produce a lot of heat. If you are growing live plants, install two fluorescent tubes that are the same length (or as close as possible) as the tank. If you have no plants, a single tube will do.

Plan on replacing fluorescent tubes once a year, whether or not they have burned out, because they grow dimmer with time.

Aquarium Thermometers

Your Bettas need a fairly consistent water temperature, and the only way to be sure they are getting it is with a thermometer. Stick-on aquarium thermometers consist of a peel-and-stick plastic rectangle applied to the outside glass near a corner. Liquid crystal film between the layers of plastic lights up in different spots as the water temperature changes.

Glass or plastic aquarium thermometers filled with red alcohol come with suction cups or hangers to secure them inside the tank. You read the temperature as you do with an ordinary fever or weather thermometer. Place the thermometer where you can easily see it but where it won’t detract from the scene inside the tank.

Aquarium Heaters

There are two types of aquarium heaters: submersible and non-submersible. Submersible heaters are entirely encased in a watertight glass tube. Nonsubmersible heaters hang on the tank’s frame; the glass tube rests in the water, but the unit must never be fully submerged. Both types work the same way: A thermostat turns the heating element on and off in response to the temperature, just like your furnace. Always follow the manufacturer’s directions to set the temperature to the desired range. (For Bettas, the range is 79 to 82 degrees Fahrenheit.)

A general rule for determining heater size is to get 5 watts of heater per gallon of water. So a 20-gallon aquarium needs a heater that is at least 100 watts.

Always make sure to unplug the heater when you remove any water from the tank. If the heater turns on while it is dry, it may get hot enough to crack when you put it back in the water.

Sponge Filter

A sponge filter draws aquarium water through a large sponge that acts as a biological medium after beneficial bacteria gather on its surface. This type of simple filter is often used in quarantine, hospital, and fry tanks.

Fluidized Bed Filter

Compact fluidized bed filters use sand as the filter medium. Water pumped through the filter keeps the sand suspended as a loose slurry. The sand provides an enormous amount of surface area on which beneficial bacteria can multiply. Constantly tumbled in the flowing water, the sand becomes what is known as a fluidized bed. The sand grains are always surrounded by oxygenated water, resulting in an excellent transfer of ammonia to the bacterial film. Gas exchange is also facilitated by this design.

A fluidized bed filter will respond quickly to extreme changes in ammonia levels caused by overstocking and overfeeding, but for routine aquarium filtration it may be more trouble to maintain than other types of filters.

Undergravel Filter

The undergravel filter was once the standard for biological filtration. This type of filter consists of perforated plastic plates that sit on risers about an inch above the bottom of the aquarium. Two to six plastic uplift tubes fit into holes in the base plates. In the simplest design, an airstone at the bottom of each uplift is supplied from an electric air pump. As bubbles rise in the uplift, water is pushed along. This causes aquarium water to flow downward through the plastic plates. Newer models use a small water pump, known as a powerhead, to suck water up through the lift tubes, providing better turnover. Powerheads can be adjusted to regulate the speed of water currents produced. The outlet often swivels to direct the water flow as desired.

With this arrangement, the substrate itself is the filter medium. Oxygenated water flowing through the gravel brings ammonia to the beneficial bacteria living on every grain. Mechanical filtration results when debris becomes trapped in the gravel bed.

A reverse-flow undergravel filter draws water through a mechanical filter, then passes it back down the uplift tubes to be distributed throughout the aquarium after it is pushed up through the gravel bed. A reverse-flow system increases the efficiency of the undergravel filter and the longevity of the bacterial colony, primarily because it reduces debris accumulation that restricts the water flow.

The major drawback to both undergravel designs is that debris accumulates in the gravel bed. Eventually, regular vacuuming (using a special aquarium vacuum tube) of the gravel becomes necessary to maintain an optimal flow, regardless of the direction the water moves.

Canister Filter

Like the simple power filter, a canister filter contains several media compartments through which the aquarium water is drawn by a pump. Water usually enters and leaves the tank via hoses connected to the filter. Hiding the hoses among plants and decorations is easy, enabling you to create a more natural scene in your aquarium. Rapid water turnover and a larger volume of filter media result in greater efficiency than can be had with a hang-on-the-back filter. For a large tank, a canister filter may be your wisest investment.

Three Types of Filtration

Biological Filtration

In an aquarium, bacteria convert deadly ammonia from fish waste and food debris to nitrites and nitrates. This critical conversion process is known as the nitrogen cycle, The nitrogen cycle is the essence of biological filtration. Every surface in an aquarium that is in contact with the water develops a film of nitrifying bacteria. Filters are often designed to provide additional surfaces for colonization by bacteria to maximize the effect of biological filtration.

Chemical Filtration

Chemical filtration is the removal of dissolved compounds from the water. For example, aquarium filters often include a compartment that holds activated carbon to absorb dissolved minerals as water passes through the filter. Various other filter media can also be used to remove undesirable compounds.

Mechanical Filtration

Mechanical filtration is the removal of particulate debris. Debris produces cloudiness and an untidy appearance. Materials such as polyester fiber floss, plastic foam, or sponges capture debris as water is pumped through them. Over time, the surface areas of all these media become covered with beneficial bacteria, and they then function as biological filters, as well.

Acrylic Tanks for Betta Fish

Acrylic tanks come in a seemingly infinite number of amazing shapes and sizes. Far lighter than comparable glass tanks, acrylic aquariums can be drilled with ordinary woodworking tools, if necessary, to install equipment.

Acrylic aquariums cost more than all-glass tanks and scratch more easily. Scratch remover products on the market will cover most simple blemishes caused by cleaning and carelessness.

An acrylic tank creates a small amount of visual distortion, due to the bending of the material during construction. These bends, however, give the tank an appealing, seamless look.

Glass Tanks for Betta Fish

All-glass aquariums are still the most popular. Made of plate glass and sealed with nontoxic silicone that allows for expansion when the tank is filled with water, glass tanks resist scratching and provide a good viewing area. One disadvantage of glass is the difficulty of drilling holes for filter parts—something that is easily accomplished with acrylic
tanks.

Glass tanks are also much heavier than acrylic tanks and can be difficult to move, especially when the tank is large. The glass must be increasingly thicker as the tank size gets larger to support the increased water pressure. Glass tanks can break, too, leaving you with a huge mess to clean up. Fortunately, such disasters are rare.

Croaking Gourami (Trichopsis species)

The Dwarf Gourami male rivals the Betta for bright coloration, and its red and neon blue markings become even more intense at breeding time. In this and other Gourami species, the pelvic fins are elongated and threadlike. The fish use them to explore the surrounding environment. Dwarf Gouramis reach only about 2 inches in length.

Blue Gourami (Trichogaster trichopterisi)

Close relatives of the Betta, Gouramis require the same aquarium care. Also known as the Three Spot Gourami, this peaceful fish grows to about 4 inches long and makes a great companion to the Betta in a sufficiently large aquarium. Males can be distinguished from females by the shape of the dorsal fin: His is pointed and elongated toward the tail; hers is much shorter and rounded at the tip. Several color variations of the Blue Gourami are available. This is an extremely hardy species that takes all common aquarium foods.

Rasboras (Rasbora spp.)

The genus Rasbora includes some of the best aquarium fishes found in Southeast
Asian waters. All remain small, seldom reaching 2 inches long. Schooling fishes
that swim among dense plant growth, they eat most types of aquarium foods with relish. Temperature and pH requirements are the same as for Bettas, making
them good choices for tankmates.

• The Harlequin Rasbora (R. heteromorpha) turns up in almost every dealer’s inventory from time to time. Pinkish-orange body coloration is accented by a black triangle at the base of the tail and the red-orange dorsal fin.
• Another relatively common species, the Scissortail Rasbora (R. trilineata) has a torpedo-shaped body. Its silvery scales have dark edges. A dark stripe runs from the midpoint of the body to the base of the tail. The outer tips of the tail fin have a yellow-black-yellow pattern of three spots. When the fish moves its tail, the moving spots give the illusion of a pair of scissors opening and closing.
• It’s worth looking for the Red-Tailed Rasbora (R. borapetensis). Like others in the genus, its peaceful habits and ease of feeding make it an ideal tankmate for the Betta. The silvery body has a pair of stripes running from the eye to the base of the tail. The upper stripe is golden yellow, the lower one is black. The base of the tail is blood red.
• Clown Rasboras (R. kalochroma) seldom school, unlike other Rasboras. In the aquarium they are peaceful and lively, darting in and out among the plants. The slender, brick red body has a black spot just behind the gill cover and another, larger black spot below the dorsal fin.
• Seldom exceeding an inch in length, the Pygmy Rasbora (R. maculatus) is also a perfect tankmate. Peaceful, it schools among plants in ponds and ditches. The red-orange body is marked with three black spots: one behind the gill cover, another near the anus, and the third at the base of the tail fin.

Glass Catfish (Kryptopterus bicirrhus)

The fascinating Glass Catfish is almost completely transparent. The internal organs can be clearly seen through the body wall. It does best in groups. Individuals usually remain together, hovering tail down among plants in midwater. A docile species, the Glass Catfish should not be kept with active, aggressive tankmates. These fish will often orient themselves facing the outflow from a power filter. In the wild, this behavior positions them to snatch food carried by the current.

Coolie Loach (Pangio kuhlii)

Grubbing about in the soft bottom mud beneath quiet water after dusk, the Coolie Loach usually rests among vegetation during the day. The dark brown body is attractively marked in yellow-orange bars from the snout to the base of the tail fin. This species makes a good scavenger for the Betta tank, as it will seek out food missed by the other fishes. In the wild, it grows to about 6 inches, but aquarium specimens are usually about half that size.

Tankmates for Bettas

For a truly splendid Betta tank, I prefer a design that mimics the Betta’s habitat, complete with fish and plants that might be found together in the wild.

Despite the fact that male Bettas fight viciously among themselves, a single male Betta rarely bothers other fishes in the community aquarium. Bettas can be successfully kept with most peaceful species of fish. Common choices include the many kinds of Tetras, small Catfishes, and livebearing fishes such as Guppies, Platies, and Swordtails. The species listed below all come from Southeast Asia.

Betta Color Patterns

There are six major color patterns found in Bettas, and these help hobbyists identify particular variations of a species. As time passes and new strains of Bettas are bred, they will be given new pattern names if they do not fit into the existing categories. The following descriptions should give you an idea of what to look for when you are searching for a particular pattern. Note that many hobbyists and breeders disagree on exact pattern definitions.

• A solid-colored Betta will have one color (bright red, royal blue, orange, or gold) that basically covers the entire body and fin areas. Solid coloration may be marred by imperfections (small specks of white or other colors), which breeders are working to eliminate.
• A bicolored Betta has a body that is one solid color with fins that are a lighter or darker variation of the same color. For example, a Betta with a light blue body and dark blue fins would be considered bicolored.
• A Cambodian Betta has a body of one color and fins of another. For example, the body on this type may be red, while all the fins are light blue.
• A butterfly Betta has a body of one color that blends into the fins near the torso area. The outer edges of the fins are a different color.
• The Cambodian-butterfly Betta, as its name suggests, is a cross between a Cambodian and a butterfly Betta. The body on this Betta will be of one color, while the fins will have two different colors. For example, the Cambodian-butterfly can have a red body with blue and gold fins.
• A marbled Betta is unique. The body and the fin tips are the same color. The inner portion of the fins is a different color, which gives this Betta a striped appearance.

Betta Fish Color

The Betta’s color is produced by pigment cells (chromatophores) in the skin. In the wild, coloration may help camouflage a fish from predators or may advertise its presence to potential mates. Wild Bettas do not possess the vibrant colors (bright red, lime green, royal blue) of their captive-bred counterparts. Fanciers have selectively bred Bettas to achieve fish with a wide range of colors and long, flowing fins. The males will develop much brighter colors than the females, and they exploit their bright coloration in mating displays designed to attract and impress females.

The Betta’s chromatophores occur in successive layers within the skin. To produce a Betta of a specific color, the other colors layered on top must first be stripped away through selective breeding to expose the desired color beneath. The top color is blue; next is red, then black, and finally yellow.

Betta Fish Fins

Bettas use their fins not only to move through the water, but also to steer and to maintain their balance. The fins are composed of long rays with skin stretched thinly between them. Special muscles attached to the rays provide control. Your Betta’s fins include one caudal fin, one dorsal fin, two pelvic fins, one anal fin, and two pectoral fins.

The caudal or tail fin, combined with the muscular tail stalk, provides the force for sudden forward bursts of speed and for fast swimming. In fancy Bettas, such as the splendens varieties, the lengthening of the natural caudal fin through artificial selection (breeding for a specific trait) has resulted in a slower-moving species than its native relative.

The sole purpose of the dorsal fin (located on the upper back region) and the anal fin (on the bottom) is to give the Betta stability, in the same way the tail assembly on an airplane keeps it stable. These fins keep your Betta in an upright position and prevent it from literally rolling over in the water.

Pectoral fins also provide stability while moving through the water and help the fish steer. Located near the bottom of the fish, directly beneath the gill openings, the pectoral fins can also be used by the male Betta to fan its incubating eggs, bathing them with fresh water to eliminate wastes and debris.

Pelvic fins are located on the hip area and also aid in stabilization and steering.

Betta Fish Swim Bladder

The Betta’s body weighs slightly more than the volume of water it displaces, so it tends to sink. So, like many other fish, the Betta has a gas-filled swim bladder that functions as a flotation device.

By making minor adjustments to the gas pressure inside the swim bladder, the Betta can remain suspended (neutrally buoyant) with little or no effort. If the Betta moves to the bottom of the tank, its swim bladder will be compressed and it will begin to sink. To correct this problem, the Betta must either add gas to its swim bladder to achieve neutral buoyancy again, or use energy to swim upward.

The opposite is true when the Betta moves toward the top of the tank. There, it must release gas from the swim bladder or must use energy to return to a deeper depth. Gas enters or leaves the swim bladder via a specialized duct. As the Betta moves about in its watery realm, small changes inside its body, unseen by the human eye, automatically maintain the proper buoyancy.

Betta Fish Scales

Scales cover the Betta’s body, overlapping each other like the shingles on the roof of a house. These thin, transparent scales help protect the Betta’s body from injury and streamline the fish for efficient swimming. A mucus layer covers the scales, reducing drag as the fish swims (this is the slimy feeling you get when you hold a fish in your hands). The mucus also helps protect against invading parasites and infection.

The Betta’s scales lack pigment. Its brilliant colors actually come from pigment cells located in the skin. The skin also produces both the scales and the mucus covering.

The Betta’s Lifestyle

Bettas prefer warm temperatures and gentle currents. They feel most secure when the aquarium provides plants that root in the bottom as well as plants that float on the surface. Betta tankmates should be non-aggressive fish that won’t harass the Betta or nip its fins. Bettas feed on a variety of small insects, mosquito larvae, and worms that they pluck from the surface of the water. In the aquarium they thrive on flakes, freeze-dried and frozen brine shrimp, live mosquito larvae, or other foods that tend to stay near the top of the water column.

Betta Fish Mouth Structure

The shape of a fish’s mouth may largely determine its mode of life. For example, you’ll find a turned-down mouth (inferior position) on bottom-dwelling species such as Catfish. These fish feed in mud, sand, or gravel, and off flat rock surfaces and plant leaves. A mouth located in the terminal position points directly forward from the fish’s face. Common among species such as Guppies and Platys that swim in midwater levels, a terminal mouth facilitates “picking off ” food as it sinks toward the bottom or floats in the water column.

The Betta’s upturned mouth, known as the superior mouth position, enables it to feed efficiently at the surface. Bettas snatch small insects and mosquito larvae from among the floating vegetation in the pond or paddy. They also greedily scoop up flakes at the top of the aquarium.

Always take care to ensure that your Betta receives its fair share of nourishment, especially if it is living in a tank with faster swimming, more aggressive fishes. Add food that sinks together with food that remains on the surface. Don’t force your Betta to compete with mid- and bottom-dwelling tankmates at feeding time.

Betta Fish Body Shape

A Betta’s streamlined body enables it to slip smoothly and effortlessly through the water. The tapered shape reduces friction, conserving the Betta’s energy as it quickly moves to catch its prey. Fish that have a more rounded shape, such as fancy Goldfish, swim more slowly and tire easily. Such fish often live in running water, where the current can aid their movements.

Fish that live in stagnant or slow-moving waters in their natural habitat develop a flattened, compressed body shape to facilitate gliding through stands of the upright reeds and plants that also favor such environments. The Discus (Symphysodon), which lives in quiet shallows along the Amazon River, provides a similar example. In fast-running water, a fish shaped like the Discus would get tossed about in the current like a leaf.

What Is a Betta Fish?

Ichthyologists (people who study fish) classify fish based on body form and structure. They group species in a hierarchy of ever more inclusive categories, from individual species such as Betta splendens to families (such as anabantids, which are fish with a labyrinth organ), to a large class, Pisces, that includes all fish. Fish represent but one class of vertebrates (animals with backbones, including humans). Other vertebrate traits include a brain case (skull) and a skeleton that protects the internal organs and supports the body weight.

Like all fish, the Betta breathes through external gills. Like other anabantids, it also has the labyrinth organ that enables it to use atmospheric air.