Diploneis smithii (Brébisson) Cleve (1894: 96)

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 : 126

Diploneis smithii (Brébisson) Cleve (1894: 96) ( Fig. 40 )

References: Hendey 1964, pl. 32, fig. 10; Krammer & Lange-Bertalot 1986, p. 291, pl. 112, figs 2–4; Witkowski et al. 2000, p. 193, pl. 90, figs 7, 15, pl. 91, figs 1, 2; Lobban et al. 2012, pl. 45, figs 3–6, pl., fig. 1; Pennesi et al. 2017, p. 205, figs 32–38.

Features: Length 42–60 μm, width 16–20 μm, striae 8–10 in 10 μm.

Description: Valves broadly elliptical with rounded apices. Raphe branches straight, ending centrally in simple pores. Central nodule apically dilated. Axial area narrow, longitudinal canals linear, slightly expanded in the middle. Transapical striae parallel, becoming strongly radiate near the apices.

Remarks: A rather variable species with several varieties described. The common feature which separate D. smithii from closely related taxa such as D. fusca (Gregory) Cleve (1894: 93) and D. nitescens (Gregory) Cleve (1894: 97) is the undivided striae, which are formed of double rows of alternating areolae (pores).

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

Figures

FIGURES 38–51. Marine benthic diatoms in coral reefs off Basra. Fig. 38. Diploneis gemmatula, Fig. 39. Diploneis nitescens, Fig. 40. Diploneis smithii, Figs 41, 42. Diploneis weissflogii, Fig, 43. Diploneis sp., Fig. 44. Navicula arenaria, Fig. 45. Navicula cancellata, Figs 46–48. Navicula carinifera, Fig. 49. Navicula cf. cincta, Fig. 50. Navicula directa, Fig. 51. Navicula distans.