The Occurrence and Vertical Distribution of the Euphausiacea of the Florida Current

The vertical distributions of the Euphausiacea present in the Florida Current are described. Light and temperature are shown to influence the day levels while the vertical distribution at night is shown to be under the control of light. During the dawn and dusk periods the paths of descending and ascending concentrations of the two most abundant species follow closely the lines of increasing and decreasing illumination values. The seasonal distribution of five species is described and the importance of light and temperature upon geographical variation of vertical distributions is discussed.