database_ultrastructure20.csv

Chemical signals play a decisive role in communication in many mammal species. In male Iberian red deer, the dark ventral patch has been recently described as a sexual chemical signal involved in intrasexual competition. Morphological specializations of the hairs of this area might contribute to retaining the volatile compounds found here. In this study, we examined the differences in ultrastructure between hairs associated with the dark ventral patch and hairs from the dorsolateral region of the body as a reference. We obtained a gallery of images from a scanning electron microscope to study the possible variation in detail anatomy and the surface and pattern of cuticular scales of hairs of the two body regions examined. In addition, we used a 2D-3D microscope to measure hair diameter (thickness) and the shape and size of the cuticular scales. We found differences in the thickness of the hairs of the dark ventral patch, which were narrower than hairs from the dorsolateral region. We also evidenced a unique cuticular scale pattern of the dark ventral patch hairs, suggesting a possible specialization of the hairs for the retention of compounds associated with this chemical signal. Moreover, some inter-sexual differences in hair morphology also support this idea. This study shows, for the first time, the differentiation of hairs related to the dark ventral patch, which contributes to the understanding of this chemical communication of Iberian red deer.