Giant Gourami

Giant Gourami (Osphronemus goramy) recommended for the advanced aquarist due to its large size (up to 70 cm) and long life (20 yrs) in captivity.  Minimum tank size 800 litres. They are hardy and peaceful towards other large fish.

The young fish has a pointed snout and about 8-10 stripes on its body. As the fish grows, its coloring gets paler, and the head becomes disproportionately large as well as a nuchal hump appears on its head.  The fish coloring varies from pale yellow to golden-yellow with a silvery tint and transverse light-blue stripes on its body. Adult coloring gets paler in time, and it becomes completely white, rosy, or gray at the end.  There are artificially bred colorings: albino, golden (with the body color varying from yellow to golden), black (with the gray-colored body and red fins), and silvery.

They have a special lung-like labyrinth organ that helps them to survive in ponds poor in oxygen. They gulp some air on the water surface and, with the help of this organ, direct the atmospheric air right to their blood flow.

In Indonesia and Malaysia, they are often “farmed” for restaurants. Gourami are tasty, with large bones and is always available in restaurants and in lots of various fish dishes, especially grilled fish.  Often served with sweet-and-sour sauce.  It is extremely popular in Javan cuisine – on Java island, almost every village has its artificial pond with gourami bred for cooking.  In the wild, they can reach an adult size of 70 cm.

Behaviour

It gets its full adult size at the age of about 4-5 years old. Provided with proper care, the lifespan is over 20 years.  Giants are interesting due to its temper, which shows some signs of intellect.  It time they will turn into nice pets with their own temper and perception and they will recognize their owner and let him touch them.

While the juveniles may demonstrate aggression, adults are very calm and quiet fish, and due to this, they are very often used for displaying in large exhibition tanks.

The fish is ok when alone in a tank, or it can live as a couple (male and female). Young fish species often fight with each other, but they become calmer as they grow. However, adult males still can demonstrate aggression towards their rivals.

The male fish has a high forehead, sharpened dorsal, and darker body coloring that becomes almost black during the spawning period. The female fish has rounded fins and fleshy lips.

At the age of eight months, being 12 cm (5 in) long, they can start breeding.

Tank Conditions

In the wild, the fish dwells in large rivers with slow flow, lakes, and bogs, including those with brackish water. Gourami prefers shallow waters with lots of water plants. The fish can breathe humid air and can survive without water for rather a long time.

One of the biggest problems is tank capacity. An adult requires a tank of 800 liters capacity and more. Even provided with not perfect tank conditions, they can grow from 7.5 cm to 50 cm long in four years. Their high growth rate can become a problem for an inexperienced aquarist since juveniles can be easily confused with the chocolate gourami, which is considerably small as an adult.

For a couple of adult fish, a tank 2 meters (79 in) long, 70 cm (27.5 in) wide, and high is optimal.

You will need powerful filters since Giants are a gluttonous eater and produces lots of organic waste!  Also, you should consider that the fish doesn’t like water flow; thus, filter and pump outputs should be directed so that there are some places in the tank without water flow.

Don’t over do the tank decorations or plants so that they have room to swim. Use large stones and snags as shelters for the fish. Tank plants have to be highly enduring with coarse leaves, for example, Anubis, since for giant gourami, any plant is food.

Make sure they can easily get to the surface of the tank to gulp air.

Compatibility

Ideal tank mates include knifefish, loricariids and large catfish, however if they are kept in a tank which is too small for them they will become aggressive.  Giant Gourami is more tolerable to other large species than their own kind. Thus, many relatively large and active fishes will do for tank mates, but they should be  big enough to not become gourami food!

Large cichlids (oscar, blood parrot, flowerhorn, green terror), catfishes (pleco, redtail catfish), loaches (clown loach, dojo loach), silver arowana, motoro, silver dollar, pacu make good tank mates.

Fish Compatibility Chart

Feeding

Giants will eat all types of food. The important  thing is the amount. Giant gourami are a large fish, and require corresponding amounts of food. There is a peculiarity – if the fish is bought as an adult (they live for a very long time), ask about its usual diet. Otherwise, it may refuse to eat the food you give since it’ll be new and unknown to the fish.  Adults just don’t like a dramatic change in their diet.  For example, initially, the fish was fed only with protein food (worms, small fishes, insects, etc.), it’ll be quite difficult to start feeding it with artificial food, and thus keeping it will become rather costly.

The easiest thing to do is to get a young fish and feed it according to the food you have available because as a juvenile they are undemanding. It’ll eat almost everything that you offer.

To keep them in good shape, you should add into their diet some high-quality flakes and specially balanced pellets for KOI or large cichlids.  Indeed, the adult fish fancies greenery and fruit, but animal protein is required for proper balanced development, especially for young fish. Shellfish, crustaceans, calamari, insects, earthworms are the source of protein for young fish.

Giants will quickly start taking food from your hand, which is quite convenient from the point of view of the tank water purity since the food goes right into the fish mouth, without fouling the water.

When catching the food, they produce specific chewing noises. Due to the special construction of their labyrinth organ, they can’t swallow large food pieces only after the second or third attempt, after taking another deep breath, they can do it.

Care

Having a labyrinth organ quite often leads to a common mistake that the tank water doesn’t require frequent changing.  This is complete nonsense as fish in such water often suffers from tissue injuries since the ammonia concentration becomes too high and they may die because of ammonia poisoning.

Regular water changes are a must. It is recommended to change 25% to 50% of the total tank volume every week.  Giant gourami tend to produce a lot of organic waste since they are gluttonous eaters. 

Giant gourami can dwell at a wide range of tank parameters and there’s only two parameters that are of key importance here: a sufficient amount of free space and clean water.

See Fish Disease Diagnosis and Treatment at Rebel Pets for help with diagnosing and treating diseases.