Ontogeny and optics of the eyes of the common prawn Palaemon (Palaemon) serratus (Pennant, 1777)

A brief review of the work on crustacean compound eyes is given. Two main types of eye have been recognized: apposition and superposition. The ontogeny of the eyes of the common prawn Palaemon serratus is examined using a variety of methods: photography of live specimens, histological sections, SEM and TEM. In common with other decapod larvae, the common prawn hatches with apposition eyes having circular lenses packed hexagonally. After metamorphosis the gradual squaring of the eye facets, begun during the larval phase, is completed. This is an essential prerequisite for the functioning of the facultative superposition reflecting optics found in long-bodied decapods (e.g. shrimps, prawns and lobsters) and some Anomura. The possible phylogenetical significance of superposition, reflecting optics is also discussed.