ABUNDANCE AND PHENOLOGY OF PSEUDOSCORPIONES (ARACHNIDA) FROM A MIXED WATER INUNDATION FOREST IN CENTRAL AMAZONIA, BRAZIL

A total of 675 Pseudoscorpiones, representing nine species, were captu red during 12 months in an inundation forest near Manaus, which is cov ered by several meters of mixedwater for 5-7 months each year. In the terrestrial phase, the average abundance of pseudoscorpions in the soi l (0-14 depth) was three times higher during the rainy season (140 ind ./m(2)/month) when compared to the season with less rainfall (48 ind./ m(2)/month). A survival strategy in response to flooding was observed in the terricolous and univoltine Tyrannochthonius amazonicus (Chthoni idae): immature tritonymphs, representing a migrating stage, moved fro m the soil to the trunk/canopy region where they passed the aquatic ph ase. Pseudochthonius homodentatus (Chthoniidae) changed from a terrico lous mode of life in Central Amazonian upland forests to an arboricolo us living in the inundation forest. Six other species, obtained in low numbers predominantly in the trunk/canopy region, are considered arbo ricolous as well. Our data reconfirm that seasonally inundated forests of the mixedwater type near Manaus represent an ecotone: Pachychernes baileyi (Chernetidae), Tyrannochthonius amazonicus (Chthoniidae), Geo garypus amazonicus (Geogarypidae), Pachyolpium irmgardae (Olpiidae) an d Dolichowithius minutus (Withiidae) inhabit blackwater inundation for ests in the valley of the Negro River. Parachernes adisi (Chernetidae) was collected from whitewater inundation forests along the lower Soli moes River. Paratemnoides minor (Atemnidae) occurs in black-and whitew ater inundation forests. Pseudochthonius homodentatus (Chthoniidae) li ves in primary and secondary (non-flooded) upland forests of Central A mazonia. The occasionally phoretic Lechytia chthoniiformis (Chthoniida e) is found throughout South America.