Diversity and functions of loricae in ciliates (Ciliophora)

The article focused on morphological peculiarities, chemical composition and function of the loricae in ciliates. Pseudochitinous (tectinous), hyaline and mucopolysaccharide loricae differ by chemical composition. There are also composite (pseudochitinous + mucopolysaccharide) and agglutinated loricae. The morphological features and associated protective properties of loricae and semi-loricae of sessile ciliates are also discussed. The increase in floatability of cells has been reported in literature as the main function of mucopolysaccharide and hyaline loricae in planktonic ciliates. It is the authors’ opinion that the main function of the lorica is to prevent the contact of extrusomes or other capturing organelles of unicellular predators or parasites from the cellular membrane of ciliates. It is also assumed that another important function of the semi-loricae and loricae in sessile ciliates is to protect joints between their stalk and zooid from hydrodynamic loads.