Deciphering the behavioural ecology of adult (sessile) sponges is challenging. However, their motile larval stages afford opportunities to investigate how behaviour contributes to dispersal and selection of habitat. Light is a fundamental cue contributing to larval sponge dispersal where photoreceptive cells contribute to this process. But how universal is light as a cue to sponge larval dispersal and settlement? Behavioural choice experiments were used to test the effect of light on dispersal and settlement behaviours. Larvae of the tropical sponge speciesCoscinoderma mathewsi,Luffariella variabilis,Ircinia microconnulosa, andHaliclonasp., from deep (12–15 m) and shallower-water habitats (2–5 m), were used in experiments. Dispersal experiments provided a light-gradient-choice where light represented light attenuation with depth. Light treatments included white light and the spectral components of red and blue light. Settlement experiments comprised a choice between illuminated and shaded treatments. Fluorescence microscopy was used to establish the presence of fluorescent proteins associated with posterior locomotory cilia. Deeper-water species,C.mathewsiandI.microconnulosadiscriminate light spectral signatures. Both species changed dispersal behaviour to light spectra as larvae aged. ForC.mathewsipositive phototaxis to blue light changed to photophobic responses (all light treatments) after six hours and behaviours inI.microconnulosachanged from positive to negative phototaxis (white light) after six hours.L.variabilis, also a deeper-water species, was negatively phototactic to all light treatments. Larvae from the shallow-water species,Haliclonasp., moved towards all light wavelengths tested. There was no effect of light on settlement of the shallow-waterHaliclonasp., but larvae in all three deeper-water species showed significantly higher settlement in shaded treatments. Fluorescence microscopy showed discrete fluorescent bands contiguous to posterior tufted cilia in all four species. These fluorescent bands may play a contributory role in larval photobehaviour.