Three weeks later in central Brazil, along the Rio Araguaia bordering the State of Mato Grosso, I fished with a different group of Indians, the Karaja. With me on this new quest had come Heraldo Britski, an ichthyologist and museum curator from Sao Paulo. A Vasp Airlines DC-3, circling first to make sure there was no livestock on the grassy runway, put us down in a field near the river village of Santa Teresinha. Here, as in Paraguay, missionaries proved valuable informants. Summoned via a communications system difficult to fathom, Tom Pope, who works as a Protestant missionary on the far side of the Araguaia, met us before the sun went down. “Piranhas? I respect them!” Tom admitted. He had been nipped once or twice while bathing in the river, he told me, but with no serious consequences. “I still bathe in the river,” he added, “and so does the Catholic padre on the opposite bank. He once swam the river to visit me. There’s a man of faith!”
Thanks to Tom, a fishing expedition soon took place. Early one morning four Karaja adults and half a dozen boys readied a slim dugout near the mission where Heraldo Britski and I had gone to meet them. There was no recognizable fishing gear in the canoe, but on the dank bottom lay a heap of carrot-sized roots and a bale of vines. The juices of these plants, belonging to the families Sapindaceae, Eurphorbiaceae, and Leguminosae, have long been used by South American aboriginal to stun fish. One of the effective ingredients is rotenone. Tom, Heraldo, and I crowded in with the Indians and the plants. Within half an hour we stood on the banks of a large midstream island. Roots and vines were loaded into baskets or onto outstretched arms, and without palaver we filed behind Luiz, the lead Indian, across rolling stretches of soft white sand. Then, unexpectedly, we came to a depression in the sand –a lagoon 30 by 60 feet and not more than hip-deep. The water was pea-soupy with algae. The boys squatted on the shore and began beating the roots to break the tough protective skins while two men waded into the pool. Each drove a heavy post into the bottom. The forked upper end would serve as an anvil for hammering juices from the vines. Accustomed by now the Indian’s indifference to the piranha hazard, I photographed these preparations, while Britski arranged collecting nets and jugs. Now the boys packed the mashed roots into loosely woven baskets and waded with them into the lagoon. Back and forth they shuffled, swishing their loads up and down in the water. Simultaneously the men bludgeoned vines on the post head (page 727). Juices released by both operations spread in the water, appearing to form a soapy froth on the lagoon’s surface. Soon fish swirled madly here and there small ones first, then larger ones. The juices were inhibiting oxygen absorption by the gills. Without a sustained supply of oxygen, any fish will quickly die. Such chemical substances, including rotenone, affect only the gills, and do not impair edibility. After weeks in the field, I could easily spot surfacing piranhas. As usual, nattereri were the most abundant, but to my surprise their bellies were bright orange or red here rather than yellow. Heraldo had no explanation. We netted many a piranha minus a tail or seriously mutilated where flesh had been ripped from the body. It was obvious that when one fish begins to weaken from the effect of the chemicals, another as yet unaffected will rise to attack his disabled brother. Often when fishing for piranhas with hook and line, I have pulled up only a head, the body having been snatched away by fellows of the same ruthless species (page 717).
What do piranhas normally eat? The ones we caught that day had dined on minnow-size characins. But these do not constitute the sole piranha diet. Years earlier in Venezuela.
Greedy gobblers at three months, piranhas hatched in the Fleischmann Memorial
Aquarium at the Cincinnati Zoo gulp ground meat. These nattereri already
try to nip the curator’s fingers; when mature, they measure 10 inches. U.S.
aquarium stores sometimes sell piranhas, but several states, including Florida,
ban imports. Floridians fear that the creatures might thrive in the state’s
subtropical waters, with disastrous effects on native fish –not to mention the
effect on people.
