Navicula kariana var. frigida (Grunow) Cleve (1895: 28)

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 : 128

Navicula kariana var. frigida (Grunow) Cleve (1895: 28) ( Fig. 52 )

References: Poulin & Cardinal 1982, p. 283, fig. 33; Witkowski et al. 2000, p. 285, pl. 132, fig. 11–14, pl. 133, fig. 5–9.

Features: Length 60–72 μm, width 23–24 μm, striae 11–13 in 10 μm.

Description: Valves lanceolate with sub-rostrate apices. Raphe branches straight, ending centrally in expanded pores. Axial area narrow, central area very small, rounded. Transapical striae parallel throughout.

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

Ecology and Distribution: This is a cold water species and has not been reported earlier from warm waters, mostly occurs in the Arctic Ocean but also found in Britain ( Whitton et al. 2003) and in Canada ( Mather et al. 2010). Not reported previously from the Gulf. Rare 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.