The true size of Arapaima gigas

[Acheloos]

Even if 2,63 is not the absolute record size, I hope you will at least agree that this is undoubtly no normal size. The arapaimas in Thailand had now about 15 years to grow, and in the fishing ponds they had very good conditions for excessive growth.
Perhaps you can manage to grow them even larger in big aquariums, but you have to keep in mind that this 2,63m specimen was already very special among the other ones, which were already unusual big. I have looked on many photos of arapaimas, including such ones from american aquariums, but there was no one which seemed to exceed 3m. Why should everthing be bigger in America?

 

[Zoodiver]

I'm not stating things are bigger in the US. I'm just stating that I have personally seen them larger than this. It just happens to be over here. Seeing them a 8 or 9 feet isn't that odd.
I'm not sure why the fish in ponds over there aren't growing the same as the ones I've seen in exhibits over here. It could be a number of factors and I think it's worth looking into.

Just curious, which American aquariums/zoos were used for looking at over all size?

 

[Acheloos]

I looked at a lot of aquariums, and actually a lot of arapaimas are even really small. To make an example of some arapaimas which are in a european aquarium in Cologne: They are there since 1972 when they were introduced there with a length of 30-40cm and are still only 1,70m. I know there are a lot of factors which influence the growth of Arapaima, and they are known to reach a weight of 10kg during one year in intensive pond culture. Actually really most of the fish from aquariums, no matter if in Berlin or in Vanquover have Arapaimas which are somewhere in the range of 5-7feet. I also looked at the arapaimas at the aquarium in Dallas, and they are hardly in the 3m range.
How did you see that the arapaimas were as big as you think? Did you measure them? The problem is that big fish are very often highly overestimated in size. I know cases in which big wels in the 2,5m range were thought to be 5m and there are a lot of similar cases. Just look some pages before, even the photo which allowed a comparison made many ones think the arapaima would be much bigger.

 

[Zoodiver]

What size anks where these smaller animals being raised in? What are the being fed?
1.7 meters is only a little over five feet for a fish over 30 years old. An arapaima should be over that size in 3 years. Also, when did you see the fish at Dallas World Aq? Several batches have been there, and are inyroduced small (1 meyer or so).

I'm still interested in learning more from your side. I'm just basing growth rate information from what it have seen: here is a pic of a 2 meter 3 year old I had. For size reference, that is a 12" pleco along the left edge and roughly 22" adult motoro stingray on the right side under it's head.

 

[Acheloos]

I don´t doubt that the arapaima is able to gain sizes of around two metres within a very short time. But this is still no proof that they are able to reach more than 3m. If you look again at the picture comparison I made some pages earlier, you can see how massive the difference between a 2m long arapaima and a 15footer would be. Are there really any arapaimas more then twice the length and more than a ton in weight in Dallas or elsewhere? I highly doubt it.

 

[Zoodiver]

I'm just saying that I have seen arapaima longer than the max sizes you are claiming.
So I was wondering where the info was coming from.

 

[Acheloos]

Zoodiver, I would have no problem to accept a bigger size than 2,65m, especially for a well-feed specimen from a big aquarium, but only up to a distinct degree. 2,7 for sure, 2,8m probably, 2,9 perhaps still okay, 3m possible. But everthing bigger than this seems very hard to believe if I look at the actual facts.

 

[Ramesh]

The ones they have on display right now were big enough to fit in my hand when we got them in back in '04 (I think it was 2004 anyway). That tells you something right there.

Here is a copy of an email I have sent to the 'Dallas World Aquarium' asking them for information about their Arpaima. When I recieve some correspondence I will post it.
If there are any other sources of actual size confirmation please contact these sources and ask for evidence.

"Hello my name is Ramesh Presser and I live in Melbourne Australia. I am doing some research on Arapaima gigas a fish species you have at your aquarium.
I am interested to know the size of your specimens and for how long you have had them?? Also the age of these fish.
These fish are claimed to be the largest fresh water fish species and I am trying to compile credable evidence of the actual size of specimens kept in different facilities around the world.
Any information and help would be greatly appreciated.

Regards

Ramesh Presser"

 

[nishant_datta]

If what you say is correct Ache, then Arapaima is not the largest fresh water fish in the world. Wels catfish and Gator Gar have been recorded at much larger sizes. And dude if you don't know (yet) whether something exists or not in the world does not mean it does not. 'Facts' / 'proof' / 'evidence' ?? This isn't a court hearing. But still check out these links:

http://en.wikipedia.org/wiki/Arapaima

http://www.aquaticcommunity.com/predatory/arapaimafish.php

http://www.fishbase.org/Summary/SpeciesSummary.php?id=2076

http://www.aquariacentral.com/fishinfo/fresh/arapaima.shtml

http://www.megafishingthailand.com/content/view/50/53/

http://www.encyclopedia.com/topic/arapaima.aspx

I'm not saying that when a lot of people say something its correct. But hey until you prove the majority wrong, lets just go with them. Also, the one who propounds something should ideally prove the same and expect others to prove him wrong.

 

[Ramesh]

If what you say is correct Ache, then Arapaima is not the largest fresh water fish in the world. Wels catfish and Gator Gar have been recorded at much larger sizes. And dude if you don't know (yet) whether something exists or not in the world does not mean it does not. 'Facts' / 'proof' / 'evidence' ?? This isn't a court hearing. But still check out these links:

http://en.wikipedia.org/wiki/Arapaima

http://www.aquaticcommunity.com/predatory/arapaimafish.php

http://www.fishbase.org/Summary/SpeciesSummary.php?id=2076

http://www.aquariacentral.com/fishinfo/fresh/arapaima.shtml

http://www.megafishingthailand.com/content/view/50/53/

http://www.encyclopedia.com/topic/arapaima.aspx

I'm not saying that when a lot of people say something its correct. But hey until you prove the majority wrong, lets just go with them. Also, the one who propounds something should ideally prove the same and expect others to prove him wrong.

I find your reasonong to be highly illogical. If you don't know something exist doesn't mean it does. Evidence and intelligent deduction must then lead to educated assumptions. By your logic anything is possible becuase we don't know. This logical fallacy is called the argument from ignorance, 'Becuase we don't know it must be true"

If there is no clear evidence of something other than anectodal evidence the credence given to such evidence is insufficient to proof it beyond reasonable doubt.
The majority of what people believe to be true has nothing to do with evidence and the facts of a particular matter.
Evidence for a claims must be brought to bear by those who believe something to be true not only by those who dipute it.
The ball is clearly in the "Arapaima 5m largest fish in the world" peoples court to prove their claims and beliefs with credible 1st degree evidence
The earth was once flat and God created the Universe 7000 years ago.
Which many/most people believed/believe dispite no evidence to continue such beliefs and sufficient and clear evidence to support the contrary.
All I want is less claims and more evidence, Picutres, places, people.
I love big fish and would love this to be proofed true but with some credable evidence which support the claims of such fish.