OSW

SIGNATURE WORK
CONFERENCE & EXHIBITION 2023

USING CIRCULAR STATISTICS TO MEASURE DEGREE OF SYNCHRONIZATION OF CIRCADIAN LOCOMOTOR ACTIVITY IN SPIDERS WITH TWO DIFFERENT EVOLUTIONARY BEHAVIORAL STRATEGIES

Name

Yueqi Wu

Major

Data science

Class

2023

About

Yueqi Wu is from Shanghai, China. She is in the Class of 2023 and majors in Data Science. She will be pursuing a graduate degree after graduation.

Signature Work Project Overview

In this work, we analyzed locomotor activity of two spider species, the common house spider Parasteatoda tepidariorum and the southern black widow Latrodectus mactans. In nature, both species are opportunistic, and capture both diurnal and nocturnal prey. Both species occupy often-shaded rocky crevices or outcrops and are thus subject to variations in onset of local darkness which enables prey capture during daylight hours while providing some protection from visual predators. However, our previous work discovered that both species experience negative masking during the photophase of light/dark (LD) cycles. The inhibited (masked) phase extends through virtually all of the photophase in L. mactans but is restricted to late photophase in P. tepidariorum. These findings suggest that P. tepidariorum is more neurologically primed for attacking prey during the late photophase whereas such neurological arousal in L. mactans spans the entire circadian cycle. Using circular statistics, our analyses revealed that P. tepidariorum has a higher degree of synchrony between LD cycles and locomotor activity than L. mactans. We then measured the distribution of locomotor activity in constant darkness for the same two species. We found that the distribution of mean vectors, indicating the preferred phase of locomotor activity, is highly concentrated for P. tepidariorum. In contrast, mean vectors in L. mactans were uniformly distributed throughout the circadian cycle. Thus, our findings suggest that the distribution of locomotor activity throughout the circadian day may correspond to different behavioral strategies in nature. Then, we also further applied our findings to two other species–A. studiosus and M. wittfeldae where we found similar patterns as P. tepidariorum.

Signature Work Presentation Video