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BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



with outside the basin of the Menam Chao Phya. In the main river 

 it occurs from below Bangkok to its head at Paknampo, and in the 

 main affluents it may also be found. The larger fish remain in the 

 deeper parts of the rivers, and only the young are likely to be observed 

 in the minor tributaries not far from the parent stream. In the Meping 

 it has been taken above Raheng and j)robably goes upstream as far 

 as the rapids. There are no very definite records for the Menam Nan, 

 the other major tributary entering the head of the Menam Chao Phya. 

 An old fisherman, who spent most of his life on Bung Borapet and 

 was very familiar with the local fishes, stated that this fish did not 

 enter the swanii^ during the annual inundation but was to be found 

 in the large rivers near the outlets of the swamp. 



Figure 82. — Pangasius sanilwongsei H. AI. Smith. Drawn by Luang Masya; courtesy o 



the Thailand Government. 



This is one of the largest fresh-water fishes occurring in any part 

 of the world, and in Thailand it exceeds in size any other fish found 

 wholly within the limits of the country. Examples over a meter in 

 length are not rare. A number up to 1,5 meters were examined by 

 the writer. The largest fish actually seen and measured was 2.5 meters 

 long, and there are various other definite records of fish of that size. 

 There is no doubt as to the authenticity of accounts of fishes 3 meters 

 long, and many people now living have seen or caught fishes that size, 

 but such colossal examples have been taken ver}^ rarely within the 

 past 25 or 30 years. A fish 3 meters long would have a maximum thick- 

 ness of nearly 1 meter and would require the combined strength of 

 eight men to lift and carry it. Old fishermen in the Ayuthia and 



