The morphology, development, and state of the photosynthetic apparatus of the diatom Attheya ussurensis Stonik, Orlova et Crawford, 2006 (Bacillariophyta) in long-term culture

The development of the marine benthic diatom Attheya ussurensis (Bacillariophyta) isolated from Ussuriisky Bay (Sea of Japan) was examined in laboratory culture. It was found that the development of A. ussurensis was characterized by a short lag phase or its absence and high growth rates (about 1.7 divisions per day) during the exponential phase. Resting cells were formed during the stationary growth phase. Morphological and ultrastructural changes in the cells of A. ussurensis during its life cycle are described based on light and electron microscopic observations. Resting cells retained their photosynthetic activity when stored in the dark for a long period of time (up to 1 year) at a temperature of 4–6°C. After 30, 60, 90, 120, 150, and 180 days of storage under such conditions, the culture of A. ussurensis was capable of regeneration due to the existence of the resting cell stage in the life cycle of the microalga.