Abstract
This study addressed the proximity at which members of the social Mexican cellar spider
Physocyclus mexicanus (Banks 1898) coexist. The study sought to determine the distance at
which males and males, males and females, and females and females will keep between each
other when kept with another individual in a capsule measuring six centimeters in length and one
centimeter in diameter. Forty-five capsules for each gender combination were observed
throughout the experiment. The mean distances between the individuals over the 21 day
experiment were 0.85 cm for the male and female pairs, 1.3 cm for the male male pairs, and 1.8
cm for the female females pairs. The mean distance between individuals for each combination of
genders was found to be different from that of any other. No difference was observed between
the mean daytime and nighttime distances for any gender combination. For each gender
combination, an increase in the distance between individuals was observed over time. The results
of this experiment reflect previously observed Pholcid social behavior. The significant increase
in the distance between male and female individuals over time is partly due to the end of their
mating season coinciding with the middle of the experiment.