Meeting Abstract

P1.20  Jan. 4  Colonization and stratification patterns among web-building spider species along the banks of several rivers in Puerto Rico LEDESMA-FUSTE, Ricardo J.*; PEREZ-REYES, Omar; HERNANDEZ-GARCIA, Pablo; THOMAS, Richard; University of Puerto Rico

Spiders are one of the most studied arachnid predators among the arboreal strata and forest floors along the rivers of Puerto Rico. One reason for such study is the fact that given the abundance of larval insects that are capable of flight in adult form; these spiders have at their disposal a vast array of prey, contributing to their selection of web-building near the arboreal and forest floor. The main objective in this research was to determine colonization patterns as well as the vertical and horizontal stratification of spiders in the banks of some rivers in the island. Treatments consisted of 8 transects localized in the bank of each river. At each treatment the number of spiders, species, diversity and abundance were calculated. The effects on spider density, species diversity and species richness were significant due to colonization and stratification. The most abundant species were: Leucauge regnyi, Wendelgarda clara, Argyrodes, Modisimus signatus, Tetragnatha, and Leucage venusta. With the removal of spider species from the experimental areas; the promoting of colonization is one that seemed inevitable. What was to be determined was the rate of such colonization as well as the positioning of the spiders once the other spiders were removed. With the similarity of nutrient availability, equal habitat availability was expected in the experimental transects. The small size of the transects allowed for rapid recruitment of colonizers from the surrounding areas. Other factors that were key to the colonization patterns as well as stratification were temperature, humidity, moisture saturation, wind changes, resource and spatial availability.