Student Research Projects

An Investigation of the Microflora of Harvestmen Genitalia

Student Areli Ibarra, '16
Faculty Mentor(s)
Department Biology
Course BIO 489: Research in the Natural Sciences


Among arachnids, the reproductive biology of harvestmen is considered unique because males directly transfer sperm to the female via a penis. In addition to the transfer of sperm, there is the potential that individuals could also exchange microorganisms during copulation. Unfortunately, little is known about the microflora of harvestmen genitalia and no pathogens or modes of transmission have been examined. In this study, I used scanning electron microscopy (SEM) to investigate the diversity of microorganisms occurring on male (penis) and female (ovipositor) genitalia of the cosmetid harvestman Cynorta marginalis. Specifically, I examined microorganisms occurring on the penis or ovipositor of 71 adults. Prior to examination with SEM, I carefully excised and dissected the genitalia of each specimen, dehydrated and chemically dried them, and used adhesive tabs to mount them on an aluminum stub. Specimens were not ultrasonicated or cleaned prior to dehydration. I sputter-coated the genitalia with gold for 2 min and examined the specimens with the Hitachi S3400N SEM at accelerating voltages of 5-10 kV. At least 10 (out of 31) ovipositors were free of microorganisms. I observed bacilli on the distal surfaces of 14 ovipositors. These bacteria occurred individually or in small colonies on the distal surfaces and on a few of the large peripheral setae. I also found cocci on the distal surfaces of seven ovipositors, but rarely observed them on peripheral setae. These observations represent the first attempt to characterize the microflora of the genitalia of a harvestman.