German zoologist Wilhelm Giesbrecht’s illustration of copepods — tiny crustaceans related to crabs and lobsters — glowing against a background that is dark like their daytime ocean environment, from his ‘Systematik und Faunistik der pelagischen Copepoden des Golfes von Neapel…’ (‘Systematics and geographical distribution of the pelagic copepods of the Gulf of Naples…’) (1892) (© AMNHR. Mickens)
(via Hyperallergic)