Fluorescence in arthropoda informs ecological studies in anchialine crustaceans, Remipedia, and Atyidae

Abstract

Autofluorescence is pervasive throughout the natural world and occurs in many animals, plants, and minerals. Fluorescent properties vary predictably over molt cycles of arthropod exoskeletons. This study examines intrinsic fluorescence in scorpions and crustaceans using novel fluorometric analyses and microscopy. Anchialine cave crustaceans, which we report here autofluoresce, are generally sparsely populated, and difficult for researchers to access. Therefore, little is known about the growth, molting, reproduction, and life history of their endemic inhabitants. Methods proposed here for measuring autofluorescence under near-ultraviolet wavelengths are valuable in informing techniques for optimal in situ observation and location of new larval forms, exuviae, spermataphores and eggs. We compare the intensity and emission breadth of fluorescent compounds extracted from California woodland scorpions (Uroctonus mordax) and California bay shrimp (Crangon franciscorum) to determine the effect of preservation duration on autofluorescent properties. Fluorescence data were obtained from anchialine cave crustaceans collected from Cenote Crustacea, Quintana Roo, Mexico and Dan’s Cave, Abaco Island, Bahamas. They exhibit peak emission wavelengths ranging from 429 nm to 515 nm and interspecific variation in emission peaks. Traits relating to emission spectra, such as breadth and intensity, may correlate with a variety of ecological parameters, such as sex, age, and reproductive state, allowing for potential field and laboratory-based applications.