2-5 mm.
В застояли води, канали.
. 0 .. 1000 m. V-VI.
HD 92/43: 1130, 1150, 3140, 3150
RDB: 04C1, 14C2, 16C2, 17C3
EUNIS: C1.22, C1.23, C1.24, C1.32, C1.33, C2.3, C2.34, C3.249, X01
PAL.CLASS.: 13.2, 21, 22.41, 22.42, 22.431, (22.12 х 22.44), (22.15 x 22.44), (22.13 х 22.41), (22.13 х 22.421), 24.1, 53.149