Fine morphology of the putative olfactory hairs in the harvestman Heteromitobates discolor (Arachnida: Opiliones: Laniatores)

Abstract

Recent behavioral studies have shown that harvestmen of the suborder Laniatores can detect odors, but no olfactory receptor has yet been identified in the group. Histology is an efficient method to infer sensilla function in arthropods. Applying this technique in this harvestmen group would be particularly interesting because it would: 1) enable the identification of olfactory receptors in animals highly dependent on chemorreception; 2) give a base for testing homologies and therefore testing the use of some sensilla as taxonomic characters; 3) enable generalizing sensilla function for other species with sensilla' morphology similar to the species studied herein. In this project, I intend to histologically characterize the putative olfactory receptors in Heteromitobates discolor (Laniatores: Gonyleptidae), focusing on the various sensilla basiconica present in different pairs of leg, and on the falciform hairs, which occur in pairs of leg I and II. The study will be conducted with histological methods based on light microscopy, scanning and transmission electron microscopy, and serial block-face scanning electron microscopy. This project is part of a broader project involving other students investigating the sensory biology of Opiliones under a morphological, behavioral and chemical perspective. (AU)