On Some Ecological Preferences of Marine Interstitial Testate Amoebas

Abstract

The impact of three ecological factors - granulometry of the sand, water salinity and water dissolved oxygen - on the marine interstitial testate amoebas from the Black Sea coast was studied. It was found that the homogeneous little grain sands [Modality (Mo) =0.10−0.80mm] were richer in interstitial testate amoebas than the heterogeneous and big grain ones (Mo > 0.80 mm). The interstitial testate amoebas were mixo-, oligo- and mesohaline and only 4 species survived in water with a salinity from 30% to 40%. The quantity of water dissolved oxygen in the studied stations varied from 4.8 to 0.5 mg/I. But the distribution of the interstitial testate amoebas was not found to be a direct function of the quantity of oxygen. Most of the psammobionts inhabit a zone where the dissolved oxygen varies from 2 to 4 mg/I. The importance of the ecological factors on the species composition and the horizontal distribution of the interstitial testacean taxocenosis on the Black Sea coast is discussed.