While writing for my website on Argentina's National Highway No. 40 (Ruta 40), about the things to visit and do close to the town of Las Lajas in the northern part of Patagonia, in the province of Neuquén, I came across a very odd river name, which did not sound like a Spanish word or a local native Mapuche word either, actually it is the same word repeated: "yumu yumu". The map below shows the location (the river coming in from the left).
It is the name of a stream, which flows in a West to East direction, down from the Andes, towards the Atlantic, down the slopes of a hill named Butahuao (2,578 m - 8,452 ft.). By the way, Butahuao is the combination of two Mapuche words: "Buta" = Big and "huao" = gully.
The river crosses Neuquén provincial highway No. 21, at Campana Mahuida (place name that combines a Spanish word Campana = bell and Mahuida, Mapuche word = hill), 54 kilometers (33 miles) northwests of Las Lajas (Spanish words: The Shale in plural).
The place name repeats a Mapuche word according to Anthropologist and Historian Rodolfo Casamiquela . He cites one of the few inhabitants of the region, Manuel Quinchao (note his Mapuche surname), from Chenque Cura, near Las Lajas. Mr. Quinchao said that it is the word is actually "llamü", the name of an animal, "a creature similar to a hog" .
There is another version which is also mentioned by Casamiquela, and he quotes Harrington-Benigar and Groeber, in which the llamü is not a pig but a crab, a freshwater crab.
I have seen these endemic crabs in the Patagonian lakes (see the photograph below where I am holding one in my hand and a close up shot on a stone):
In case you are not too familiar with Spanish and Argentine Spanish in particular, the double "L" or "LL" is pronounced all over the Spanish speaking world -except Argentina- as the English "Y" in "Yes" (so "llumü" would sound like "You-moo" in English).
However, the Argentine Spanish pronounciation has a different sound for the double "L". It sounds like the "Sh" in "Show", and in fact it sounds identical to the Spanish pronounciation of the letter "Y".
By the way, the double "L" is not ever pronounced in the way that the double "L" in "million" is pronounced in English. So a "Llama" is not a "lama" but a "Shama" (Argentina) or a "Yama" (rest of Spanish speaking countries).
Argentines pronounce "LL" and "Y" with the same sound, the rest of Spanish speakers have two distinct sounds for those phonemes. That is why "llamü" became "yumu", (an Argentine pronounces both words in the same way: "Shoe-moo"). And this is the reason why a word written with a double "L" changed to a "Y".
In case you wonder why Argentines pronounce the language differently (Uruguayans do to), it is due to the enormous influx of Italian migrants to both countries in the late 1800s and early 1900s. Half the Argentine population has Italian blood in their veins. So the Italian accent mixed with the Spanish one, softening it. (you can hear it in this Video spoken in "Argentino" or Argentine Spanish).
But getting back to our pig or is it a crab? Which is the correct interpretation? To name a stream after the crabs that live in it sounds quite reasonble. So does naming a river after pigs. But the point is that pigs were not native animals. They were brought to America by the Spaniards. The Mapuche word for pig, hog is "Sanchu" (san-chew) which is the phonetic rendering of the Spanish word for pig: "Chancho" (chan-chou). This is logical, they adopted the Spanish word for pig.
Yes, there was a wild pig, native to America which is now extinct in Patagonia, but was known to the Mapuche: the Pecari tajacu or Collared Peccary (pictured below), which had different Mapuche names: sohue, sürse, sañhue, sanue, chanue, sane, saino. Distinct from the "Sanchu" name given to Eurasian pigs.
So what was the yumu, a pig or some other creature?
I have my doubts, I have come across the following explanations, all duly backed by bibliography:
- "Llamü are little frogs of different sizes that lived in the rushes" 
- Cuchi is another name for pig, and is used in Cuchivilu, or cuchi = pig, vilu = snake, the Snake-hog creature of Patagonian lakes.
- Llamü according to a nineteenth century dictionary means "blind" 
- Yumu derives from the Mapuche word "yumid", to shine, bright, glistening, shiny.  Which would be appropriate for a brook.
The question will remain open for now.
 Casamiquela, R., (2003). Toponimia indígena de la Provincia del Neuquén pp. 57
 Martin Alonqueo, (1985). Mapuche: ayer-hoy, Editorial San Francisco, pp. 135
 Andrés Febrés, Antonio Hernández, (1846), Diccionario hispano chileno
 Hasler Juan A. Topónimos Mapuches. AUCh, °5 serie N°
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2014 by Austin Whittall ©