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FAQs on Arowanas Behavior

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My Arowana Tank (.com)


Maintaining the pinkish shading on juvenile silver Arowana into adulthood    10/1/14
I was interested by Neale's (five-year-old) reply concerning colour enhancement in the Arowana. It stated, if I read it aright, that the colouration was essentially genetically pre-programmed, and could not be
enhanced or changed post-birth: although beneficial maintenance of natural genetic colouration could be preserved by carotene e.g. in crustacean shells or, presumably by extension, such foods containing it - Hikari Cichlid Gold - for instance.
<Mmm; well; my interpretation may be different: The "potential" for coloration is genetically allowed; however, nutrition, water quality, other factors DO play their role in ongoing expression>
I have a juvenile (5") silver Arowana with the most beautiful shimmering pinkish colouration to all its fins as well as a clearly defined pink edging border marking each of its scales. It would be fantastic if this
colouration could be preserved into adulthood - what a spectacular fish that would be!
Sadly, the man in the LFS said that it 'would soon fade' presumably to a uniform silver.
<Mostly, yes>
My question - is this inevitable? Or have I got myself a fish that with a carefully thought-out plan for its dietary care could defy the 'normal' inevitable descent into blandness?
<Good foods (Carotenoids containing), regular partial water changes (weekly); avoiding stress and trauma... will aid in sustaining the luster and overall beauty of this specimen through the years. Bob Fenner>
Neale on: Maintaining the pinkish shading on juvenile silver Arowana into adulthood    10/1/14
<<Greetings both. Yes, pretty much stick with what I’d written before. Colouration in fish is largely genetic, with some “ecophenotypic” variation as its called, i.e., mood, diet, injury, etc causing modifications through life. In short, much like people. Algae and crustaceans seem to be the source of many/most nutrients fish use to develop colours, most obviously carotenes. A few species becoming more red or orangey if offered high-carotene diets (cichlids of various types, some barbs as well) hence the “colour enhancing foods” sold by many retailers. But as Bob F suggests, if it’s fated for a fish species to change colouration as it ages, it generally will. Juvenile Arowanas do indeed have warmer colour tones, but as they are, silvery-green is the default. Some line breeding in Asian Arowanas has changed this, but South American ones are, so far as I know, still wild-type. Their much bigger adult size, usually much less tractable personalities, and the lesser intra- and interspecific variation within Osteoglossum spp. have made them much more difficult to intensively breed than Scleropages spp.>>
Re: Maintaining the pinkish shading on juvenile silver Arowana into adulthood    10/1/14
My thanks: he will have the best water care in a stress-free solo tank in a quiet traffic area - plus the best varied diet I can source for him.
Beauty, I trust, will ensue!
<Let us hope! Cheers. BobF>

Enhancing the gold colour in Asian Arowana -- 09/03/09
Dear WWM Crew,
I am interested in learning how to enhance the gold colouration in the Asian Arowana, in particular the golden variety. I would appreciate if you could point to relevant literatures in this respect, if any.
Many thanks and best regards
Seow Lim
<Colour in Asian Arowana is largely genetic, and you "get what you pay for". As with any fish though, the best colours depend on environmental factors and a good diet. Most fish should their best colours in a dark
tank, in particular things like a dark substrate (black sand for example) and overhead shade provided by floating plants. A stressed fish won't show its best colours, so you need to ensure an Arowana has plenty of swimming space and excellent water quality. Tankmates, if any, shouldn't be aggressive or nippy. Diet is central, since at least some fish colours can only be produced when the fish eats the right things. In particular, algae and crustaceans seem to be influential. In terms of algae, pellets may work best, either directly, or stuffed inside frozen fish or prawns. For crustaceans, things like *unshelled* shrimps and krill work well. On the other hand, a bad diet will mean an unhealthy fish, so a loss of colour.
Live feeder fish would be the obvious, most foolish way to feed an Arowana since these have a very high risk of introducing parasites. Furthermore, carp family fish (such as Goldfish and Minnows) contain a lot of fat, and there's ample evidence this caused problems in predatory fish. Similarly,
thiaminase is an issue, so you want to restrict foods that contain this substance to once or twice per week. Goldfish and Minnows (and seemingly all carp) contain this stuff, another reason not to use feeder fish. But
numerous seafoods contain it too, including shrimps.
So, in short, you can't add colour to an Arowana beyond what its genes allow, but you can ensure you get the very best colours your fish can have by providing the right habitat and the right diet. Cheers, Neale.>

Re: Enhancing the gold colour in Asian Arowana -- 09/03/09
Dear Neale,
Many thanks for your almost instantaneous reply.
<My pleasure.>
Whilst I recognise that the colour of the Asian Arowana is largely genetic, I was wondering whether the use of certain colour enhancing substance such as Astaxanthin would help to bring out the best of the gold colour in the golden Arowana.
<Not substantially. If you could feed an Arowana and make it look like a more expensive one, then that's what people would be doing! Why buy a $5000 Arowana when you can just feed a $50 one and get the same results! While there's plenty of "colour enhancing foods" out there, none of them make a huge difference.>
This usually involves two processes. The first is to reduce the dark colouration on the back of the golden Arowana which I understand is due to the effect of counter shading so that the back colour will be lightened
exposing the shine of the fish.
<Not sure I quite understand this. Fish generally make their backs darker to match a dark substrate. The idea is to become less visible to predators (like birds) above them. Bright lights above them (like the sky) makes them lighten the colours of their bellies, so that they're less visible to predators underneath them (such as bigger fish). Whether or not Arowana do this is debatable, particularly in the case of farmed, artificial forms.>
The second is the attempt to bring out the gold colour of the fish which I understand is done in a number of ways including the use of lights in what some refer to as "tanning" as well as the use of colour enhancing foods or supplements.
<The food supplements specifically mimic the chemicals in crustaceans and algae mentioned earlier, for example carotene. Regular fish foods often lack these chemicals. Colour-enhancing foods have extra amounts of them, so that the fish can produce their best colours. Only specific colours are enhanced; e.g., carotene improves reds. Carotene is found in crustacean shells, hence my suggestion to use whole, unshelled crustaceans. If you're feeding a diet that already includes algae and whole crustaceans,
colour-enhancing foods will have little/no effect.>
I would appreciate if you could share some of your knowledge with us.
<By all means experiment, but don't expect dramatic results. Most of the colour on an Arowana comes from its genes, and to some degree how well these are displayed depends on its environment. A varied diet will enhance those colours, but it won't dramatically change them.>
Many thanks and best regards
<An interesting topic worth discussing. Thanks for writing.>
Seow Lim
<Cheers, Neale.>

Baby silver Arowana constantly terrified?    2/16/08 Hello, I am writing to you out of concern for my silver Arowana. Guess I should start with the details: 1 baby silver Arowana, 4 inches long (nose to tail-tip) 1 inch "tall" Tank size: 55 gallons (long) currently, once he gets larger he will be moved to a 200 gallon Tank mate: 1 Siamese algae eater, 1.5 inches long (nose to tail-tip) Temp.: 75 - 80F Ammonia: 0 Nitrite: 0 Nitrate: usually <10 I add a bit of aquarium salt (the marine salt variety, not the cheap boxed stuff at Wal-Mart) with each water change (10-20% at the end of each week) <Arowanas don't need salt, and in fact few species naturally occur in brackish water. So unless you have some overwhelming reason to add salt, I'd tend to skip this.> I have had my Arowana for about a month and a half (The tank used to contain gouramis and has been fully cycled for a year.) About a week ago, when I woke up, I found my Arowana, Percival, darting frantically against the side of the tank, like he was trying to swim through the glass. The tank has a hood, of course, and a light which I don't really use at all (sunlight during the day, no light at night.) He looked absolutely terrified, but he was not "gasping" or breathing any faster than normal. He kept swimming at the glass, darting up and down, trying to get "through." He has not stopped since that morning a week ago. He darts up and down the same side of the tank, wearing himself out. Sometimes he rests on the gravel at the bottom of the tank, hiding in his fake plants. This is very scary to see, since Arowanas are supposed to glide gracefully at the surface. Since his snout has been rubbing against the glass for so long, he's got a white "scab" built up. It's not a fungal infection, since it's not strand-like or fuzzy. It only appears on his snout where he has been rubbing it against the tank. I am adding the aquarium salt and a little Melafix to hopefully prevent any infection, though the wound isn't open. <Not a big fan of Melafix, though perhaps useful enough as a preventative. If the wound does go bad, do turn to a "proper" medication.> What could be causing this behavior? He swims like he's terrified, like something is chasing him. I don't know what to do for him, I've tried covering the tank for a day to block out any light, but this hasn't helped. I tried to do more frequent water changes, but he only becomes more terrified and I'm afraid he'll have a heart attack or knock himself unconscious! I hate to see my once majestic baby so utterly frantic for no apparent reason. Please help, and thank you so much for your time. -Amber <There are two likely issues. The first is the size of the tank. Arowanas are open water fish, and they can be easily spooked in small tanks. They will often try to jump, and in doing so, damage their snouts, which is likely the cause of the physical damage you're seeing. The second issue could be the placement of the tank. Things like loud TV sets, banging doors, or simply people constantly moving past the tank can make fish nervous. This varies of course, and some fish settle down quickly, but others do not. In any case, I'd think about whether the tank is in the best place in your home. Do also add some big floating plants to create shade. This will help inhibit its jumping behaviour. Do also review water chemistry; while Arowanas are definitely adaptable, extremely hard or soft water won't be appreciated. Fish tend to be nervous when water quality or chemistry aren't in their "comfort zone". Check water quality an hour or two after feeding, just to make sure that the zero ammonia/nitrite levels you report actually hold 24/7. Cheers, Neale.>

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