Hedriocystis zhadani Mikrjukov, 2000

Diagnosis: Shell ovoid, transparent and homogeneous, about 50 µm in diameter; pores without conical knobs. Massive stalk about one fifth of the capsule diameter and 2-3 times the capsule diameter in length. The cell body, 25-40 µm in diameter, gives rise to numerous filopodia extending in all directions. The nucleus occupies a central position. Filopodia are about as long as the capsule is wide, they bear numerous granules. The stalk is very massive, up to 8 µm in diameter and usually exceeds 2 or 3 times the diameter of the capsule. No contractile vacuoles were observed. Often form colonies on organic substrates or algae, possibly resulting from the absence of the swarmer.

Ecology: Marine, White Sea

Remarks: The taxonomic position of this species is questionable.