A STUDY OF THE ENVIRONMENTAL CONDITIONS IN A BOG POND WITH SPECIAL REFERENCE TO THE DIURNAL VERTICAL DISTRIBUTION OF GONYOSTOMUM SEMEN

Abstract

The vertical distribution of this green, euglenoid-like organism in a bog pond was studied at intervals of 4 hrs., throughout 24 hrs., with reference to air temp., water temp., illumination at the surface of the pond, total-, free-, and bicarbonate CO2, O, and pH. The practically undisturbed condition of the water in the pond made it possible to demonstrate an O and a CO2 "pulse." These are mainly the result of the photosynthetic activities of Gonyostomum. The acidity of this pond is partly due to the acid water which enters from the sphagnum bog. A striking chemical characteristic of the pond is the sudden increase in free CO2 content of the water between 0.5 and 1.0 m. Many individuals of the Gonyostomum population move upward during the early morning hrs. and congregate in maximum numbers somewhere between 1 m. and the surface. The level at which this occurs seems to depend on the proper combination of light, water temp., and CO2. During the late afternoon and night many individuals move downward so that the maximum counts are found in the lower layers.