Student Research Projects

Preliminary Analysis of Bacteria Associated with Temperate Harvestmen

Student Alex Poteet
Faculty Mentor(s)
Department Biology
Course BIO 489: Research in the Natural Sciences


Harvestmen (‘daddy long legs’) are unique among arachnids in that they generally ingest solid food particles. As a result of their unusual feeding mode, the gut of harvestmen may host an interesting, and previously unexamined, bacterial community. Very little information is available in the literature concerning the microbiota associated with arachnids. I undertook a preliminary study with the objective of characterizing the number and diversity of bacterial types present on and inside adults. Bacteria present on the outside of the Harvestmen were obtained simply by rinsing the spiders in tryptic soy broth and plating the broth on trytpic soy agar. The individuals were then surface-sterilized in dilute bleach solution and homogenized in trytpic soy broth to obtain bacteria present internally, which were then plated on trypic soy agar and eosin methylene blue agar. I found a large variation in the number of bacteria present both internally and externally between different individuals. Gram-positive cocci were routinely found to be externally present. Gram-negative rods were commonly isolated from the internal preparations and included lactose nonfermenters, though lactose fermenting (coliforms) were occasionally recovered.


Science Undergraduate Research Travel Award


National Conference on Undergraduate Research, Mar 31-April 2, Ithaca, NY