Entomoneis paludosa (W. Smith) Reimer

Figs 11, 12, 13, 14

Observation.

LM (Fig. 11). Frustules panduriform in girdle view (Figs 11A-D). Frustule dimensions (n = 19): length 34.2-80.7 μm, width 12.8-21.8 μm at constricted part, 22.4-30.3 μm at widest part. Keel high. Hymen strip region distinct, worm-like (i.e. curved from apex to valve centre, widest near distal end), located close to the raphe canal (Fig. 11A-D, indicated in Fig. 11C, see also Fig. 12A, B and D). Junction line slightly sinuous (Fig. 11, see also Fig. 12A). Striae visible under LM, 22-25 in 10 μm . Girdle bands numerous.

SEM (Figs 12 and 13). Frustule panduriform, composed of epivalve, girdle bands and hypovalve (Fig. 9A and B). Junction line confirmed same as LM observation (Fig. 12A, dotted line). Costae mostly running from raphe canal to mantle. Hymen strip region composed of costae and hymen strips (Fig. 12A and D, two arrows, respectively). This type of hymen strip belongs to Type One hymen strip, which are a siliceous membrane strip perforated by irregularly distributed round pores (Fig. 14E). Mantle thickened (Fig. 12C, arrow). Cells having a 4:2 configuration of girdle bands, i.e. four girdle bands associated with epivalve and two associated with hypovalve (Fig. 12C-E, labelled in Fig. 12E). Fibulae having only two levels: raphe fibulae and basal fibulae (Fig. 13A and B, two arrows, respectively). Internally, one cell bearing only one lumen, no sub-compartment present (Fig. 13C-F).

Ecology and distribution.

Entomoneis paludosa was commonly found on the stone surfaces in Lake Qinghai with E. sinensis and E. qinghainensis and it has a global distribution. Entomoneis paludosa is a dominant species in the sampling sites.