Trachyneis aspera (Ehrenberg) Cleve (1894: 191)

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 : 130

Trachyneis aspera (Ehrenberg) Cleve (1894: 191) ( Fig. 57 )

References: Hendey 1964, p. 236, pl. 29, fig. 13; Witkowski et al. 2000, p. 355, Pl. 159, figs 1–6, 9; Lobban et al. 2012, p. 293, pl. 48, figs 4–9; Stidolph et al. 2012, pl. 33, fig. 34.

Features: Length 72–98 μm, width 18–20 μm, striae 9–10 in 10 μm.

Description: Valves linear lanceolate with rounded apices. Raphe branches straight, terminal endings hooked to the same direction. Axial area narrow, central area transapically dilated forming fascia widened towards the margin (staurous), terminating before valve margin. Striae appear in transverse and longitudinal rows, strongly radiate in the middle.

Remarks: Observed specimens are slightly narrower than those reported by Witkowski et al. (2000).

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

Figures

FIGURES 52–61. Marine benthic diatoms in coral reefs off Basra. Fig. 51. Navicula distans., Fig. 52. Navicula kariana var. frigida, Fig.53. Navicula transistantioides, Fig.54. Navicula sp., Fig. 55.Seminavis sp., Fig.56.Trachyneis antillarum, Fig.57.Trachyneis aspera, Fig. 58. Trachyneis clepsydra, Fig. 59. Trachyneis debyi, Fig. 60. Tracyneis velata, Fig. 61. Donkinia carinata.