Talk:Arapaima
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If anyone runs into free licensed pictures of this please add :O I just thought it'd be cool after reading http://msnbc.msn.com/id/8404622/ where it was described as dinosaur like. gren 30 June 2005 15:41 (UTC)
- I couldn't find an image, so I took this one. Sorry it's so dark; I'll try to get a better one. Ginkgo100 00:10, 5 March 2006 (UTC)
[edit] Size
The length of 4.5 metres is greatly exaggerated. The largest reliably measured Arapaima was 2.63 m (8 ft. 7½ in.) long, weighed 185 kg (407 lb.), and had a girth of 165 cm (65 in.). It was caught by British angler Joe Taylor in Bung Sam Lan Lake, Thailand, on August 26, 2001 (interestingly within its introduced distribution). A picture with details can be found on FishBase Arapaima picture page, though, ironically, FishBase recognizes the 4.5 m maximum length on its Arapaima species summary page.
And for some reason Guinness World Records has recognized this figure in recent editions. However, previously they listed the largest confirmed specimen at 2.48 m (8 ft. 1½ in.) length, and 147 kg (325 lb.) weight, caught in the Rio Negro river, Brazil, in 1836.
Now, if a 4.5 m (14 ft. 9 in.) long Arapaima had similar proportions as the two measured individuals, it should weigh c. 900 kg (2,000 lb.) – not 200 kg (440 lb.). In fact, with the proportions of a typical European Eel, a fish this long would weigh c. 170–200 kg (370–440 lb.). Needles to say, the proportions of the claimed size are just impossible for an Arapaima. Strange, that claims this absurd get recognized by such authorities.
And thus, the Arapaima is also shorter than Giant Mekong Catfish. Wels Catfish (Silurus glanis, 256.7 kg/566 lb.), Yellowtail Catfish (Pangasius pangasius, 208 kg/460 lb.), Giant Pangasius (Pangasius sanitwongsei, 200 kg/441 lb.), and Nile Perch (Lates niloticus, 188.6 kg/416 lb.) have also reached greater weights than Arapaima. But it is the largest freshwater fish species in South America.
The Wels Catfish, mentioned above, should be the longest freshwater fish. The 256.7 kg specimen, caught in Desna river, Russia (now Ukraine) in 1918, measured 3.35 m (11 ft.) long, and there's a report of a 3.6 m (12 ft. 9½ in.), 180 kg (397 lb.) individual from Sweden in 1871 (I'm unsure if this is still recognized by Swedish authorities). And there are unconfirmed reports of similar length as the largest Arapaima claim, and even longer. A shame there's no Wikipedia article for this species...
The fish on the picture is in fact no catfish at all, but a Huso huso, a very large sturgeon which was once common in the river Danubia. If you take a closer look to this fish, and compare it with both Huso and wels, you see that this is undoubtless no wels. Cause of the bad qualitiy and the very bad perspective, the pointed snout of the short-nosed huso is nearly not visible. Because this species of sturgeon is a very active hunter of other fish, it has a very large and wide mouth, what lead to the false interpretation that it were a wels. I have even found a picture from a internet-site about caviar, which showed a new photo of a huso in blach and white, and in nearly the same position, and it looks nearly identical to the fish on the picture. The body of the wels has another shape, and they have also large barbels on their snouts, which this fish has not. Therefore you can see the short and small barbels husos have under their snouts. The actual record catfish was caught some years ago in Italy, it was an enormous fish of 2,78m and a weight of 144kg, much bigger than any other wels whose existence was proven. The false maximum size of the Arampaima has its origin in the beginning of the 20th century. The Indians were asked by the german Biologist Hans Schomburg how large this fish grow, and they said it could reach 200kg and 4,5m. This dates were copied by thousands of authors, and nearly none of them has ever made own research, or any calculations about size-weight-relations. In fact there was never any known specimen from South America which came only close to this size, only the arampaimas which grew up in fishing-ponds in Thailand, managed to reach a size close to only 3m.
- Thank you for this correction. I never actually paid that much attention to that picture. And though I'm no fish expert, these are two very different species, and I certainly would have noticed this in a color photo. The weight of 144 kg (317 lb) is certainly more plausable as a record, than 256 kg, considering the fact that nowadays individuals more than 2.5 m (8 ft 2½ in) in length and 100 kg (220 lb) are very rare. Indeed, I later noticed that the old Swedish record is way out of proportion as well; and after collecting information on seemingly reliable large Wels individuals there was a huge gap between the 256 and the 144 kg individuals, with no records in between.
- With this cleared up, the question is: what now is the longest freshwater fish? There is a record from 1993 of a 3 m (9 ft 10 in) 242 kg (533 lb) Giant Mekong Catfish, but I've read that the length may not be accurate – though this species is firmly the heaviest with the 293 kg (646 lb) 2.7 m (8 ft 10½ in) individual caught in 2005. The Alligator Gar (Atractosteus spatula) is another possible candidate with a 2.96 m (9 ft 8½ in) 137 kg (302 lb) specimen from 1953.
Arapaima's average length has been recently reported at 1.3 m (4¼ ft.), and another source gave the mean weight at 20 kg (44 lb.). And since Arapaimas reach sexual maturity at 1.5 m (5 ft.), most of the Arapaimas today are immature. Consequence of overfishing no doubt.
The longest fish which swim in freshwater are beluga sturgeons(Huso huso) which can reach in expetional cases a length of more than 5m. But they normally live in the sea and come only in the freshwater to spawn. Large sawfish, which can grow longer than 5m, also sometimes swim up in the rivers of Australia. The longest fish which live in freshwater for their whole live, are giant freshwater stingrays. They have a very long whip-like tail, and can reach lengths of more than 4m.
[edit] Fish sizes
- There should probably be a separate article Largest freshwater fish that addresses all these claims, so that all the candidate species articles can link to it instead of trying to reproduce the verbiage each in slightly different and possibly incorrect ways. Article is likely to be of general interest, fisherfolk always being fascinated by fish size. Stan 06:00, 3 January 2007 (UTC)
- I agree. We could then make reference to the new article in regard to these claims. This has been thrown about before but nobody has gotten around to doing it. Volunteers? --Ginkgo100 talk 17:59, 3 January 2007 (UTC)
- The Largest organisms article cover these claims, though currently missing a proper amount of citations. MiltonT 02:17, 28 February 2007 (UTC)
- I agree. We could then make reference to the new article in regard to these claims. This has been thrown about before but nobody has gotten around to doing it. Volunteers? --Ginkgo100 talk 17:59, 3 January 2007 (UTC)
[edit] Air-breathing
The Arapaima are renowned and famous for being able to breathe air from the surface due to a lung-like lining to their throat. I don't feel the article makes this sufficiently clear, so I am planning to add it in. Liamshaw 16:41, 14 February 2007 (UTC)
Note that the beluga sturgeon is not considered to be a truly fresh water fish because it spends a large part of its lifecycle in brackish or salt water. Secondly the sturgeons do not have a truly bony skeleton and as such are also ineledgible for consideration as the heaviest bony fish known. 212.159.21.158 13:18, 11 April 2007 (UTC)
