Morphological observations of fluorescence in different tick species (Family: Ixodidae)

Ticks are important ectoparasites due to their ability to transmit harmful pathogens and their study is thus significant for medical and veterinary practices around the world. Fluorescence has been found in numerous biological organisms, including ticks. However, the overall function, evolutionary significance, and distribution of fluorescence in ticks are unknown. This study examined tick fluorescence in purchased, unfed adult Amblyomma americanum (Linnaeus), A. maculatum Koch, Dermacentor variabilis (Say), D. andersoni (Stiles), Ixodes scapularis Say, and Rhipicephalus sanguineus Latreille ticks. An Olympus SZX7 microscope and NightSea SFA system with ultraviolet (UV) and royal blue sets were used for observing tick morphology. Ticks were shown to have widespread fluorescence in all species observed. The results corroborated previous studies, but with the addition of more fluorescent structures. Tick fluorescence could potentially play roles in communication or predator avoidance. Studies on tick behavior in conjunction with fluorescence are now called for to elucidate potential roles.