GROWTH RATES OF ALGAE DETERMINED <i>IN SITU</i> USING AN IMMERSED MICROSCOPE¹

Abstract

SUMMARY A microscope was adapted for immersion in natural aquatic habitats to make direct observations of attaching microorganisms. Using this technique the growth of several types of algae was followed. The algae observed exhibited a diurnal growth pattern. Most of the size increase occurred during the daylight hours, whereas most cellular division occurred during the night. Growth rates determined by size measurements varied from 1.3 to 1.8 doublings per day.