REU 2021 Student Spotlight

Jesse Margolies

Jesse is an undergraduate student at Arizona State University who spent his summer in the EELab as part of FIU's NSF-funded

Coastal Ecosystems Research Experience for Undergraduates (REU) Site program.

Jesse developed and conducted a research project to investigate how salinity effects sea urchins, both in adults and during early development.

NSF REU Site

Throughout the summer, Jesse learned to conduct sea urchin righting assessments; sample tube feet; extract DNA; spawn and cross urchins; raise embryo and larval cultures; measure larval body size; and perform salinity tolerance assays. He also participated in animal care and aquarium maintenance.

Jesse's project focused on the effects of different salinities on DNA methylation levels and the physiology of the sea urchin Lytechinus variegatus.

Salinity affects DNA methylation

Jesse conducted righting response assays using the sea urchin Lytechinus variegatus. This is a common method used to assess echinoderm physiology in which the animal is placed upside-down, and the time it takes to correct itself is recorded. Jesse found no apparent effect of different salinities on righting response time. However, he did find that patterns of total DNA methylation varied by salinity.

Salinity impacts early development

Jesse raised L. variegatus embryos under different salinities, and found that they were not able to successfully develop at low salinities (25 ppt). He also found that larvae raised at 35 ppt tended to be larger than those raised at 30 ppt. He then placed the two groups of larvae into short-term salinity treatments to estimate their tolerance to both low and high salinity levels. Larvae raised at 35 ppt appeared to have a slightly greater tolerance to high salinity levels than those raised at 30 ppt. As more frequent and extreme storm events are predicted to increase as climate change continues, sudden and dramatic changes in salinity due to rainfall may negatively affect these urchins during early development.