Ref ID : 4711
F.G. Agamaliev; Ciliates of the Low-Salinity Lagoons of the Caspian Sea. Arch.Protistenk 131:201-214, 1986
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The species composition and ecology of the microbenthic and periphytonic ciliates of three low-salinity lagoons of the Caspian Sea (the Little Kysylagach bay, the Agrakhan bay and the Divichinsky lagoon) were investigated. In all, 112 ciliate species belonging to 22 families were encountered; 97 species occurred in the microbenthos and 65 in the periphyton. In the microbenthos, 72 species were found in the Little Kysylagach bay, 66 in the Divichinsky lagoon, and 56 in the Agrakhan bay; in the periphyton 42, 36, and 30 species were recorded, respectively. The open Caspian sea and the lagoons shared 48 common species. The main background of the ciliate fauna of the lagoons was formed by freshwater species (about 70%). The marine forms occurred mostly (32 species) in the Divichinsky lagoon, which can explained by its somewhat higher salinity. The ciliate fauna shows three seasonal maxima of development: in spring, summer, and autumn. The spring and summer peaks of abundance are the highest ones in both the microbenthos and the periphyton. The ciliates are most numerous in muddy sediments with organic detritus and fragments of plants, where their year's average abundance attains 7.8x10E6 cells/m2. The main part of the fauna occurs in the uppermost layers of the sediments (0-1 and 1-2 cm). In muds, 80% of the species occur in the layer 0-1 cm, while the maximum depth of penetration of the ciliates into the sediment reaches 5 cm. In muddy sands and clean sands, the ciliates penetrate down to 10 cm. The periphytonic ciliates are most diverse and abundant in the overgrowth of stones and metal constructions. Eurytopic species form the main background of the periphyton of the lagoons. However, various substrates show considerable differences as to the diversity and abundance of the ciliates.