Giant Gourami: Care Guide, Tank Mates, Facts, & More (With Pictures)

The Giant Gourami is the largest of all labyrinth fishes…big, powerful, and an overall awesome fish!

The Giant Gourami Osphronemus goramy is a stunning fish when it gets large. In their natural environment natives have reported lengths of almost 2 feet (60 cm). It has even been suggested by Vierke (1978) that it can get as large as 2 1/3 feet (70 cm). Now that is one big gourami! Fortunately in captivity they are scarcely over 16 inches (40 cm) and it’s only a rare specimen that reachs close to 18 inches (45 cm). But that is still a good-sized fish.

This is the largest of all the labyrinth fishes and in its native countries it is affectionately called the “Water Hog”. It is an active fish with a high metabolism and it eats a lot. They are believed to have originated in Java, and possibly Sumatra, Borneo, and other islands in the Malay Archipelago, but their range is much greater today. They have been introduced into a number of countries throughout Southeast Asia where they are fished and cultured as a delectable food fish. They are also highly prized for use in public aquariums because of their size and ease of care.

These fish are usually sold in sizes of 1 1/2 – 3 inches (4 – 8 cm) in pet stores. When they are small they have a pointed snout, a flat head, and an attractive banded coloration. Juveniles have stripes of a silvery blue/gray to black on a cream to golden/yellow background. As they get older they loose the stripes and turn the color of the fish in the photo above, or sometimes completely black. Adults develop a swollen forehead (especially the males), along with thick lips (more pronounced on females), and a thick chin. Other common names they are known by include Common Gourami and True Gourami.

This is not a difficult fish to keep, but because of its size it will need a very large aquarium and so is generally kept by more experienced aquarists able to provide a large environment. A juvenile can start out in a 30-gallon tank, but an adult will need a minimum sized tank of 200 gallons. If keeping it with other fish an even larger tank is suggested. A well-cared for specimen will attain its full adult size in about 4 to 4 1/2 years.

Though these gouramis will grow into a very large strong fish, they make a very personable pet. They will come to know you and some people even report being able to pet their fish. They can be kept in a community aquarium but their temperament with tank mates is changeable. They are usually peaceful with other large fish and adults will usually only become aggressive it their tank is too small. Good tankmates include knifefish, large catfish, and the loricariid (plecostomus) catfish from South America. When raised and kept into adulthood they do “own” their tank. So it’s important to realize that the fish they are raised with will be fine, but new additions are at risk of being killed.

As they are large and active, they will need minimal tank decorations. A good decor includes a dark colored substrate to bring out their colors, a few pieces of driftwood or some rocks, and  some sturdy plants around the perimeter of the tank and floating at the surface. They do eat plants however, so they need to be fast growing species. With its large appetite it will put a heavy load on the water and the filtration. A weekly water change of up to 50% is recommended and needed.

• For information on keeping freshwater fish, see: Freshwater Aquarium Guide: Aquarium Setup and Care

Habitat: Distribution / Background

The Giant Gourami Osphronemus goramy was described by Lacepède in1801. They are believed to have originated from the Greater Sunda Islands in Java and possibly Sumatra, Borneo, and other islands of the Malay Archipelago. Their range is much greater today as they have been introduced to several countries for aquaculture purposes. In several countries, including Australia, they are commercially raised as a food fish. They are also found in the Lower Mekong Basin: Malayan peninsula, Thailand, Cambodia, and Vietnam as well as waters of China, Singapore, and eastern India. They are considered an important and savored food source.

This gourami is one of 4 currently recognized species in the Osphronemus genus. This genus is commonly referred to as the giant gouramis and all are very similar in shape and very large. The Giant Red Tail Gourami O. laticlavius, which reaches a length of 20 inches (50 cm), is also occasionally found in the aquarium trade. But only the Elephant Ear Gourami O. exodoney vies with this species for the title of the largest labyrinth fish. Both reach almost 2 feet (60 cm), but it has been suggested by expert and author Jong Vierke (1978) that this species can get as large as 2 1/3 feet (70 cm), which would make it the champion in size. The other Osphronemus species include:

• Elephant Ear Gourami Osphronemus exodon (Roberts, 1994)
• Giant Red Tail Gourami Osphronemus laticlavius (Roberts, 1992)
• Kaloi Sarawak, Giant Gourami Osphronemus septemfasciatus (Roberts, 1992)

This species is listed on the IUCN Red List as Least Concern (LC). The occurrence of this species is very wide, it is common and there are no major concerns identified. They are widespread, abundant, and well adapted in all suitable habitats across their range. They are both wild caught and cultured for use as a popular food fish as well as an aquarium species.

Other common names they are known by include Common Gourami and True Gourami. They are also sometimes referred to as the Golden Redfish, which is problematic because this is also a common name for the ocean perch Sebastes norvegicus, though that fish is usually called the Rose Fish. This species is also sometimes called by common names usually associated with other gouramis, including the Banded Gourami, Rainbow Gourami, or Striped Gourami.

They inhabit lowland medium to large rivers as well as lakes, and they will enter flooded forests during the wet season.They are also found in the stagnant water of swamps and marshlands as well as in canals where the water moves sluggishly. They have even been found in brackish water. Their habitats are heavily vegetated and they are opportunistic feeders that will consume both plant and animal matter. Their natural diet consists of aquatic weeds, fish, frogs, earthworms and sometimes even dead animals.

• Scientific Name: Osphronemus goramy
• Social Grouping: Solitary – This fish is mostly a loner.
• IUCN Red List: LC – Least Concern

Description

The Giant Gourami is laterally compressed with a deep bodied oval shape and a blunt head. As juveniles their head is flat and pointed, but as adults they develop a ‘nuchal hump’, a swollen knob or lump on the forehead, along with thick lips and a thick chin. The forehead of the male tends to be larger than on the female, while the lips of the female tend to be the thicker of the two. The ventral fins are threadlike. Like all other gouramis they have a special ‘labyrinth organ’ which enables them to survive in oxygen-depleted waters. This organ is a part of the fish which allows it to absorb atmospheric oxygen directly into the bloodstream by gulping air at the surface of the water.

In the wild they may reach almost 2 feet (60 cm) in length, though in captivity they rarely grow over 16 inches (40 cm). It has even been suggested by Vierke (1978) however, that it can get as large as 2 1/3 feet (70 cm). They will be able to breed at about 6 months of age when they’ve attained a length of about 4 3/4 inches (12 cm). They are a very long-lived fish with an average lifespan of over 20 years with good care.

Juveniles have yellow fins and 8 – 10 dark bars. The bars are a silvery blue/gray to black on a golden/yellow background, giving them a striped appearance. The color fades as they mature and they become rather plain, generally with a brownish black or even an overall pinkish to white coloration.

In recent years dyed varieties of the Giant Gourami have been appearing in the hobby. Many albino and transparent type fishes make an ideal ‘canvas’ for applying color to an otherwise rather plain specimen. Color is added to fish by various methods, but with this fish it is thought to be through a process involved in dying the fish by injecting colored dye under the skin. Concerns are over the initial stress and possible pain to the fish, followed by a possibly higher susceptibility to infection during the process. It is also thought possible that it could shorten their lifespan. As a consumer you will want to be aware of these concerns. The combined buying power of aquarists makes a difference on what is made available.

• Size of fish – inches: 27.6 inches (70.00 cm)
• Lifespan: 20 years – The average lifespan of this long-lived fish is about 20 years, and up to 25 years with proper care.

Fish Keeping Difficulty

This is a hardy fish and easy to keep, but because of their adult size they will require a large aquarium. They are undemanding and will accept a wide variety of foods, but are also active with a voracious appetite. They make a good choice for an experienced fish keeper with a very large tank and a strong filter, to handle the bio load these fish produce. Tankmates also need to be large and relatively non-aggressive. They can live for 20+ years, so it takes a long-term commitment to house this fish. They are very much worth the time and energy needed to keep them though, as they have personality not seen in many fish.

• Aquarium Hardiness: Moderately hardy – This species is very robust however the tank requirements mean a lot of work and commitment on the aquarist’s part.
• Aquarist Experience Level: Intermediate – This fish requires a very large tank so is suggested for more experienced aquarists.

Foods and Feeding

The Giant Gouramis are omnivores. In the wild, they will eat aquatic algae as well as fish, crustaceans, frogs, worms, and even dead meat. In captivity, they will generally eat all kinds of foods.To keep a good balance offer a high quality flake or pelleted food everyday. Besides regular fish foods they will even eat cooked meat, bread, boiled potatoes and other vegetables. Only offer beef heart or any other meat from mammals rarely, as they are not able to properly digest these foods. Feed brine shrimp (either live or frozen) or blood worms as a treat.

This is are not a very picky eater and although it can be a voracious predator, this fish will eat almost any freshwater aquarium foods if it is trained to do so at an early age. If they are mainly fed live fish, your food bills will be very high so it is suggested that you start to train them on the dried foods as soon as they are obtained. Generally feed once or twice a day.

• Diet Type: Omnivore – Specimens may need to be taught to accept processed foods and it is recommended that the fish keeper begin this as soon as the fish is acquired.
• Flake Food: Yes
• Tablet / Pellet: Yes
• Live foods (fishes, shrimps, worms): Some of Diet
• Vegetable Food: Some of Diet
• Meaty Food: Some of Diet
• Feeding Frequency: Several feedings per day – Generally feed once or twice a day.

Aquarium Care

These gouramis are big fish that put a large bio load on the aquarium, so need ample filtration. They are extremely hardy fish and though the labyrinth organ allows the fish to survive in oxygen depleted water, it is a common misconception that this makes water changes unnecessary. This is hardly the case as these fish will suffer the same tissue damage from built up toxins as any other fish. Regular water changes are a must with 25 – 50% weekly being recommended.

• Water Changes: Weekly – Weekly water changes of 25 – 50% are recommended.

Aquarium Setup

The Giant Gourami will swim in all parts of the aquarium. These fish grow large, huge actually. A juvenile can start out in a 30-gallon tank but as adults they will need a very large aquarium, 200 gallons is recommended. They are hardy and quite disease-resistant, so can handle a variety of water conditions. This is one of the few labyrinth fish that has some salt tolerance so can be kept in slightly brackish water conditions. However it not suited to a full brackish water tank. It can tolerate a salinity that is less than 10% of a normal saltwater tank, a specific gravity of less than 1.0002. But they need clean water, so you will want to have a good filtration system with a moderate water flow, and do large weekly water changes, with 25% or more being reasonable.

These gouramis will show their colors best on a dark substrate. As they are large and active, they will need minimal tank decorations. The tank should be decorated in a way which allows it unobstructed movement. These fish like to have areas to hide which can be provided with a few rock structures and bogwood. Providing plants along the parameter of sides and back of the aquarium is also nice. They will enjoy thick areas of floating plants too but they will feed on the plants, so use fast growing species.

• Minimum Tank Size: 200 gal (757 L) – Juveniles can be kept in a 30 gallon tank, but as they mature a 200 gallons or more will be needed.
• Suitable for Nano Tank: No
• Substrate Type: Any
• Lighting Needs: Moderate – normal lighting
• Temperature: 68.0 to 86.0° F (20.0 to 30.0&deg C) – Keep the surrounding room temperature consistent with the water temperature to avoid causing trauma to the labyrinth organ.
• Range ph: 6.5-8.0
• Hardness Range: 5 – 25 dGH
• Brackish: Sometimes – Can tolerate a low salinity of less than 10% of a normal saltwater tank, a specific gravity of less than 1.0002.
• Water Movement: Moderate
• Water Region: All – They will swim in all areas of the aquarium.

Social Behaviors

The Giant Gouramis are generally good community fish. Somewhat loners, they may fight fish of the same species when they are young. As they get older they mellow out but males tend to be aggressive to one another and may fight, rendering the well known gourami “kiss” in an aggressive ritualized manner.

Their size and natural diet will allow them to eat smaller fish, so watch out for any smaller tankmates. Sometimes though, predatory fish that are never fed any live fish, will grow up not knowing that other fish should be considered dinner. There are reports of large sized Giant Gouramis living peacefully with small tetras or danios.

They can be kept in a community aquarium and are usually peaceful with other large fish. Adults will usually only become aggressive it their tank is too small. Good tankmates include knifefish, large catfish, and the loricariid catfish (plecostomus) from South America. When raised and kept into adulthood they do “own” their tank. So it’s important to realize that the fish they are raised will be fine, but new additions are at risk of being killed.

• Temperament: Peaceful – This fish will become increasingly predatory with age, so choose tankmates with care.
• Compatible with:
  • Same species – conspecifics: Yes – Can be kept singly or in pairs. Groups are possible with a large enough aquarium. Males are territorial and will tussle amongst themselves, and become aggressive when breeding.
  • Peaceful fish (): Monitor – Although the fish is generally peaceful, very small tankmates may be eaten.
  • Semi-Aggressive (): Monitor
  • Aggressive (): Threat
  • Large Semi-Aggressive (): Monitor
  • Large Aggressive, Predatory (): Threat
  • Monitor
  • Shrimps, Crabs, Snails: Threat – is aggressive
  • Plants: Threat

Sexual differences

The male Giant Gourami has longer and more pointed dorsal and anal fins. Mature males will also develop a larger ‘nuchal hump’, a swollen knob or lump on the forehead. The females dorsal and anal fin will be rounder and they may have thicker lips than males.

Breeding / Reproduction

Like most fish in this family, the Giant Gouramis are bubble nest builders. Breeding itself is relatively easy but a difficult task to perform in the aquarium. Providing a breeding tank that is massive enough for these huge fish is perhaps the biggest challenge. It helps that they reach maturity and are able to breed at about 6 months of age, at a length of about 4 3/4 inches (12 cm). But they will still require a very large breeding tank.

In the wild the male will build a ball-shaped nest out of bits of plants just below the surface of the water. They vary in size but are usually about 16″ (40 cm) wide and 12″ (30 cm) deep. A circular entrance, about 4″ (10 cm) across, always points toward where the water is deepest. The nests are mostly constructed in April and May, though spawning takes place throughout the year. The male will take 8 to 10 days to construct his nest, anchoring it to reed stems at between 6 – 10″ (15-25 cm) below the water surface.

The spawn will result in about 1,500 to 3,000 eggs being release. Their eggs as well as the fry, are lighter than water and float to the top. The male will gather the eggs in his mouth and place them in his nest. The eggs hatch in about 40 hours and the male will guard the offspring for about 14 days after the spawn. See additional descriptions of breeding techniques for labyrinth fish in: Breeding Freshwater Fish: Anabantoids.

• Ease of Breeding: Moderate – Although the fish is not difficult to breed, the breeding tank must be massive.

Fish Diseases

Giant Gouramis are very hardy so disease is not usually a problem in a well-maintained aquarium. Some diseases they are prone to are bacterial infections, constipation and Hole in the Head if good water quality, nutrition, and maintenance is not provided. With any additions to a tank such as new fish, plants, substrates, and decorations there is a risk of introducing disease. It’s advisable to properly clean or quarantine anything that you want add to an established tank prior to introduction, so as not to upset the balance.

These fish are very resilient but knowing the signs of illness, and catching and treating them early makes a huge difference. An outbreak of disease can often be limited to just one or a few fishes if you deal with it at an early stage. The best way to proactively prevent disease is to give your fish the proper environment and a well-balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish is more likely to acquire disease. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.

Availability

The Giant Gourami is readily available both in stores and online, and is moderately inexpensive with prices range depending on the size.

Featured Image Credit: Watcharin Tadsana, Shutterstock