Herbarium MUHW, Marshall University, Huntington, West Virginia, USA and Herbarium QCA, Catholic University, Quito, Ecuador.
E-mail: evans@marshall.edu
The indigenous Shuar and Achuar of southeastern Ecuador employ several plants to kill or stun fish. Those most commonly used are Lonchocarpus utilis A.C. Sm. and varieties, Tephrosia sinapou (Buc’hoz) A.Chev., and Clibadium surinamense L. ( = Clibadium asperum (Aubl.)DC). All are woody plants, cultivated in gardens and harvested nondestructively. In the former two taxa, root sections are dug, pounded into shreds and introduced in the stream or pool with a vine basket or simply thrown into the water. In the latter, upper leaves and infructescences are collected, pounded into a wet pulp and introduced into impounded water with a basket passed back and forth for maximum distribution. In each case fish become disoriented in a matter of minutes and are easily caught and eaten without ill effects. In both Lonchocarpus (Timu) and Tephrosia (Payash) the active compound is rotenone the action of which is well known. In Clibadium (Masu), the piscicide is reported to be ichthyothereol, a polyacetylenic compound which apparently acts as a neurotoxin. Presence of polyacetylenes, produced and stored in reservoirs, is suggested by fluorescent action and calorimetric detection on nitrocellulose tissue prints. In general, reservoirs of varying length are located abaxially in lower order veins and variable to higher vein orders. Involucral bracts possess reservoirs of relatively large diameter compared to those of leaves.