Pleurosigma diverse-striatum Meister (1935: 102)

Al-Handal, Adil Y., Thomas, Evan W. & Pennesi, Chiara, 2018, Marine benthic diatoms in the newly discovered coral reefs, off Basra coast, Southern Iraq, Phytotaxa 372 (2), pp. 111-152 : 131

Pleurosigma diverse-striatum Meister (1935: 102) ( Fig. 62 )

References: Hendey 1970, p. 152, pl. 6, fig. 62; Al-Handal 2009, p. 24, fig. 153; Stidolph et al. 2012, pl. 8, fig. 166.

Features: Length 60–90 μm, width 16–20 μm, oblique striae 18–22 in 10 μm, transapical striae 16–18 in 10 μm.

Description: Valves sigmoid-lanceolate with acutely rounded apices. Raphe branches sigmoid, central, and eccentric near the apices. Axial area narrow, central nodule small and rounded. Striae appear in oblique and transverse rows. Oblique striae crossed each other at angle of 65 o.

Remarks: Under light microscope, this species looks rather similar to Pleurosigma inflatum Shadbolt (1853: 16) but can only be separated by raphe angle which is +8–13 o in P. inflatum and +17–22 o in P. diverse-striatum .

Ecology and Distribution: A widely distributed marine species. Previously reported from the Gulf both from muddy and sandy sediment ( Hendey 1970, Al-Handal 2009, Al-Yamani & Saburova 2011). Frequent in Basra corals.

Figures

FIGURES 62–74. Marine benthic diatoms in coral reefs off Basra.Fig. 62. Pleurosigma diverse-striatum, Fig. 63. Pleurosigma strigosum, Figs 64, 65. Plagiotropis lepidoptera, Fig. 66. Stauroneis sp., Fig. 67. Amphora arcuata, Fig. 68. Amphora arenaria, Fig. 69. Amphora cf. commutata, Fig. 70. Amphora cingulata, Fig. 71. Halamphora coffeaeformis, Fig. 72. Halamphora costata, Figs 73,74. Amphora graeffeana.