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e) 
é FISHES OF WESTERN SOUTH AMERICA 
In the backwaters of the Ucayali and Pacaya rivers I observed the use of 
weirs of two types: 
The first was nothing more than a fence-like line of brush, palm fronds, ete. 
thrust into the bottom across the shoals of the quiet backwaters, forming a light 
barricade. They could be expected to halt rather than hold large fishes, especially 
Arapaima. ‘The operator of the device stationed himself in his dugout alongside 
the barrier. A large fish in its efforts to break through would agitate the fence 
sufficiently to direct the aim of his harpoon. (Fig. 33). 
The second type of weir is of more stable, more permanent and effective con- 
struction. (Figs. 25 and 26). It is a pole fence of considerable height, allowing 
for the rise and fall of water from season to season, bound together with lianas. As 
the preceding it is placed across the narrower passages of backwater channels, from 
bank to bank. At mid-channel a tight pound, or four-sided enclosure, of similar 
structure, is built. At the front-center of this a gate is suspended so as to swing 
inward freely, not outward. During the oncoming rainy season and rising waters, 
larger fishes, seeking passage upstream in the usual manner, nose their way along 
the barrier, find the gate, enter, and are unable to escape from the pound. As 
needed, the inhabitants get their fresh fish by clinging barefoot to the stringers 
around the top of the fence, and spearing the day’s selection from above. 
Kahn (1931, page 88) has given us the story of the cwmaru, a fish which feeds 
on the explosive seeds of the plant walaba on the bank. The fish has learned to 
wait nearby for this food, and to recognize the popping of the seed-pods, in answer 
to which they come rushing to be first. The Djukas have learned to imitate the 
popping with a sharp handclap so as to lure the cwmaru within striking distance. 
A most unusual fishing method is described by Orton (page 478), and by Paez 
(page 416). Both had seen Indians wading and dragging canoes, lashing the water 
with branches. Fishes in panic would frequently make the wrong turn and leap 
into the canoes. Iam well prepared to believe this story from the number of times 
I have seen fishes leap inboard when disturbed by the ordinary paddling movement. 
Fishing in holes with the bare hands is sometimes done, as I had caught bull- 
heads in boyhood; this is mentioned in a previous section, concerning the taking of 
Orestias in Lake Chinchayeocha. White (Beebe, page 481, et. seq.) describes the 
drives of Arowona into shallow water where they could be picked up by hand. 
Almost as extreme a case of fishing without tackle is that described by Paez 
(page 153). Fishes were taken in the fresh hide from the head of an ox. To this 
they would cling tenaciously until pulled out of water. In my observation this 
occurred only in the case of Hemicetopsis (q.v.), not worth taking for food. 
André and others allude to the employment of dynamite in fishing. In parts 
of the country near enough to mining centers to make dynamite available, I found 
the population not more averse to its use than here at home. Many sections were 
found greatly depleted of fishes, and available dynamite was freely alleged as the 
reason. I found it a convenience at times when other methods failed, and with 
reluctance carried it well-packed in my saddle-bags, or baggage. 
Many authors describe at more or less length the use of poisons of various 
