Trachyneis clepsydra (Donkin) Cleve (1894: 192)

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 clepsydra (Donkin) Cleve (1894: 192) ( Fig. 58 )

References: Donkin 1861, p. 8, pl. 1, fig. 3 (as Navicula clepsydra Donkin (1861: 8)) ; Witkowski et al. 2000, p. 355, pl. 159, fig. 11.

Features: Length 110–130 μm, width 20–25 μm, transapical striae 12 in 10 μm.

Description: Valves linear lanceolate with rounded apices. Valve face slightly depressed in the middle. Raphe branches straight, ending centrally in simple pores deflected to the same direction. Axial area narrow, central area rounded to transversely dilated. Striae appear in transverse and oblique rows.

Remarks: Observed specimens have parallel transapical striae, slightly different from those illustrated by Witkowski et al. (2000) which have slightly radiate transapical striae.

Ecology and Distribution: A widely distributed marine species. Previously reported from the Gulf ( Hendey 1970, 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.