Plankton of the Florida Current.

II. Siphonophora

Siphonophores present in the Florida Current off Miami have been studied for 18 months. The seasonal distribution of each species is described together with its vertical distribution, diurnal migration and cycle of alternation of generations. When comparison has been possible, results agree fairly well with those from the Bermuda area. It was shown that, superimposed on seasonal fluctuations in numbers, most species vary somewhat in relation to the water mass present. In this locality, water mass change is associated with temperature changes. The siphonophores as a whole adjust their day level in relation to the temperature.