Temporal resolution in the eyes of marine decapods from coastal and deep-sea habitats

Temporal responses of eyes from four decapod species taken from sublittoral (Pandalus montagui Leach), coastal [Nephrops norvegicus (L.)] and deep-sea [Paromola cuvieri (Risso) and Chaceon (= Geryon) affinis A. Milne Edwards and Bouvier] habitats were examined. The electroretinogram responses to a r ange of sinusoidal intensity modulations between 0.5 and 40 Hz were recorde d. Recordings were made from individuals adapted successively to two backgr ound light intensities: The sublittoral and coastal species showed faster r esponses when adapted to the higher light level and they also responded bes t to intermediate frequencies. When adapted to the lower light level, all s pecies responded most strongly to low-frequency stimuli. Physiological and ecological reasons for the differences in responses are suggested.