Student Research Projects

Comparative study of Central American cosmetid harvestmen (Opiliones, Laniatores)

Student Lindsey Inzana ‘14
Faculty Mentor(s)
Department Biology
Course Biology 489: Research Methods in the Natural Sciences


Currently, the genera Paecilaema and Paecilaemana are defined on the basis of relatively few characters (number of tarsomeres on leg I and dorsal armature). Different species in each genus have been defined on the bases of variation in sexually dimorphic structures (cheliceral size and armature of leg IV), body size and color patterns. There are many undescribed species of cosmetid harvestmen that could be placed into either genus, as currently defined. In this study, I examined adult males and females representing 15 species for the genera Paecilaema and Paecilaema, including specimens of 8 described and 7 undescribed species. Specimens were field collected in Panama, Costa Rica, Honduras, El Salvador and Belize. I examined and compared a total of 52 morphological characters. I observed considerable interspecific variation in the following structures: size of ocularium, scutal outline, armature of areas I, III, and IV, prominence of the scutal grooves, shape of the paracheliceral projections, armature of the free tergites, tooth number and shape on the fixed and movable finger teeth of the chelicerae, shape and number of dorsal and ventral tubercles on the femur of the pedipalp, and tarsal formula. The results of this project will be used to formally describe several new species from Panama and Costa Rica. Future research will include an examination of the male (penis) and female (ovipositor) genitalia using SEM. Data based upon reproductive structures will be combined with the character data that I collected to complete a formal redescription of the genus Paecilaema in Central America.