MORPHOLOGY AND LIFE CYCLE OF AMOEBOFLAGELLATE PHARYNGOMONAS SP (HETEROLOBOSEA, EXCAVATA) FROM HYPERSALINE INLAND RAZVAL LAKE

摘要

The morphology life cycle, feeding and multiplication of amoeboflagellate Pharyngomonas sp., strain RL isolated from hypersaline inland Razval Lake were studied. The life cycle includes flagellate, amoeboid, and cyst stages. Flagellated cells have two anterior flagella and two posterior flagella emerging apically from the anterior end of cell. Nucleus localizes closely to the base of flagella. Longitudinal groove is on the ventral side of cell. Flagellated cells have distinct cytopharynx in the anterior part of ventral groove. Cytopharynx passes into the intracellular channel reaching the posterior end of cell. Amoeboid cells have two morphotypes - heterolobosean and lobosean. Cysts are spherical, their wall is smooth. The cell division is occurred either at the flagellated stage or at the amoeboid one. Distinctions of Pharyngomonas sp., strain RL, from Phatyngomonas kirbyi were determined. They consist in longer flagella and long filamentous branching pseudopodia at the posterior end of amoeboid cells. Morphological distinctions are in good agreement with differences in the structure of 18S rRNA gene. They may be used for the species differentiation of Phwyngomonas species.