Welcome to features about Arowanas. In this series of articles, there will be articles about each type of arowana and its characteristics. Arowanas are Jurassic fish and have been around for 100 million years now. They have bony heads, elongated bodies, large heavy scales and mosaic pattern of scales in 5-6 rows. They have long dorsal fins and anal fins with small but elongated pectoral fins. Asian arowanas have much larger caudal fins than the silver arowana. With an oblique mouth and wide gape and two distinct barbels on the lower jaw, Arowanas are carnivores. Bony fish is the species they have evolved from.
Arowanas jaws and tongue bear many teeth. Toothed bone on the base of the mouth has teeth that bite against teeth on the roof of the mouth. Arowanas suck oxygen from air into the swim bladder.
Being specialised surface feeders, arowanas are also excellent jumpers with the silver arowana being able to leap 6 feet from the water to pick off insects and birds from any overhanging branches in the Amazon. If they are reared in captivity, they grow to 2-3 feet and outgrow tanks in 8-10 months. For arowanas, 150 gallon tanks are the minimum in size with 400-600 gallons being the ideal size.
All arowanas are demanding in nature and can only really be kept by dedicated and experienced aquarists. Any sudden change in PH levels or oxygenation or filter can kill them within one week. Because they are extremely heavy eaters, lots of waste is produced in the tank which severely effects the water conditions. Therefore, the ammonia and nitrite and nitrate content can become hazardous. Water changes should be about twice per week with 20% of the water being changed.
Younger arowanas can be raised in groups of 6 if kept in 150-400 gallon aquariums but once they reach maturity within 2 years they become territorial and aggressive as they are solitary by nature. Only keep parrot fish, stingrays, pacu, catfish, oscars, jaguar cichlids, gar, clown knifefish as partners in the same 400-600 gallon tank.
If kept properly, Arowanas can live 15-20 years if healthy. Because they are classed as being mouthbrooders, arowanas build nests and protect the young by carrying hundreds of eggs in their mouths.
Essential for arowanas to thrive are the following conditions: Well filtered, soft and slightly acidic water at 28 degrees centigrade with PH scale of 4-6 being the right balance to keep the species in optimum health. Be aware that Arowanas are intolerant of changing conditions so any change in filter or changing akll the tank water can create sudden changes which can kill them. Any spike in ammonia, nitrates can kill them as well so only make 10% in water changes in any week.
What are the physical characteristics of Arowanas and what are the unique types
of behaviour? Some arowanas are red, hence the species called red arowana while
there is also the golden arowana. Rainbow arowana has colours of the spectrum.
Silver arowanas are endemic to South America. Platinum arowanas are pure form
of silver and highly prized.
Arowanas consume flies, scorpions, centipedes, mealworms, crickets, live frogs, earthworms,smaller fish like goldfish, guppies, tetras. Besides these, they also love to eat carrot pieces, fruit pieces, insect larvae, daphnea, blood worms, krill, vegetables, fruit pieces. Prepared foods ideal for Arowanas include prawns, lean pork, frozen fish food, pelleted food. All species are voracious predators. Once they become
accustomed to the owner, they can easily be hand fed.
What are the varieties of Arowana:
- Green arowanas have grey body with green edged scales and dark striped tails and are the most common variety and are found in Kalimantan and Sumatra in Indonesia, Vietnam, Myanmar, Thailand, Cambodia, Malaysia. Price wise. they are the cheapest of all the Arowanas to purchase
- Super Red from Western Borneo are the most valued with the gills, fins, edges of the scales being red and the core colour of the scales being silver. Scales can be red, gold, purple. Sub varieties of the super red can be pink, orange, blood red, dark red
- Cross back golden has gold and dark green scales. Also known as the Malaysian Golden it is endemic to peninsular Malaysia. Scales on this species have sparkling golden shine. Body is silver green.
- Red tail golden is endemic to Northern sumatra with golden scales up to the fourth scale near the top of the body
- Premium red tail golden has gold coloured gills and dark green back
- Jardini Arowanas are Australian and known for green pearl and red pearl varieties of the species. They have 7 rows of scales
- Asian arowanas have 5 rows of crescent shaped coloured scales with black tails marked by gold spots bandings
- Silver arowanas are totally silver in scales and fins. They have long tapered tails and are the most common and cheapest varieties. Being flatter with larger heads, they are distinctively different from Asian arowanas and do not like to eat frozen food but prefer to take floating small fish and shrimp
- Black arowanas have tapered tails but the scales and fins are black in colour
- Australian spotted arowanas are also known as spotted barramundi