The Comparative Photobehavior of Laboratory-Hatched and Plankton-Caught 'Balanus Improvisus' (Darwin) Nauplii and the Effects of 24-Hour Starvation

摘要

Stage II nauplii of Balanus improvisus were obtained from laboratory maintained adult barnacles. The immediate phototactic and photokinetic response of laboratory nauplii to light stimuli of known wavelength (460-540 nm) and quantal intensity was determined. Spectral and light intensity responses were compared with previous results. Responses of fed and 24-h starved laboratory nauplii were also compared at three different salinities. Starvation for 24 h, although inducing no major change in photopositive and photokinetic response of nauplii, can slightly depress spontaneous swimming speed and raise the threshold of intensity response for phototaxis.