Color factors influencing larval settlement of barnacles, Balanus amphitrite subspp.

Influence of the color of substrata on the settlement of cyprid larvae of barnacles, Balanus amphitrite subspp., was studied using larva collecting plates colored with paints of four different luminosities in each of four different hues: red, yellow, green, and blue. It was revealed that the cyprids discriminate between luminosities in each hue and respond differently to given luminosities, either being attracted by lower luminosities or escaping from higher luminosities, indicating an important role of negative phototaxis in larval settlement. However, the sensitivity of the cyprids to light stimuli differs between regions of the spectrum; the cyprids are far more sensitive to green than to red, and green discourages their settlement at much lower luminosity levels than red does.