ECOLOGY AND THE STRUCTURE OF RESPIRATORY ORGANS IN A UNIQUE AMPHIBIOUS TERRESTRIAL ISOPOD FROM THE NEOTROPICS (ONISCIDEA, PHILOSCIIDAE)/

The respiratory organs of the isopod Prosekia tarumae Castro, 1984 (On iscidea: Philosciidae) consist pseudotracheae functioning as pleopodal lungs, and gill-like pleopods where the thin walled exopodite is capa ble of functioning as an aquatic respiratory organ. These structures e nable the amphibious/terrestrial species to inhabit Central Amazonian inundation forests and to live just above and below the water line of annually flooded tree trunks for 5-7 months. Ecological data indicated , that the reproductive period in P. tarumae is restricted to the fore st floor during the terrestrial phase, that it is an univoltine, omniv orous and fast running, nocturnally-active species. In addition, ecolo gical data on Circoniscus gaigei Pearse, 1917 (Oniscidea: Sphaeronisci idae), a non-amphibious/terrestrial isopod from the same biotope, are given.