Pteroncola cf. inane

Sabir, J. S. M., Theriot, E. C., Lobban, C. S., Alhebshi, A. M., Al-Malki, A. L., Hajrah, N. H., Khiyami, M. A., Obaid, A. Y., Jansen, R. K. & Ashworth, M. A., 2018, Systematics of araphid diatoms with asymmetric rimoportulae or densely packed virgae, with particular attention to Hyalosynedra (Ulnariaceae, Bacillariophyta), Phytotaxa 347 (1), pp. 1-49 : 25

Pteroncola cf. inane ( Figs 62–64 )

Material studied: —Cultured material ( UTKSA 0078), isolated from collection SA29, sediment collected from the submerged rocky bottom at the Obhur area of Jeddah, Kingdom of Saudi Arabia ( 21° 43.535’ N, 39° 06.949’ E).

Description: —Specimens were 7–10 μm long by 1.8–2.3 μm wide, with exceptionally densely spaced virgae ( 72–77 in 10 μm), a pore field neither sunken nor separated from the valve face, a symmetric rimoportula at each pole, and bilayered wall construction ( Figs 62–64 ). Vimines were not complete across the virgae in some specimens ( Fig. 62 ). When complete, they formed uniseriate striae between the virgae ( Fig.64 ). A single row of pores occurred through the internal membrane at the face-mantle junction. Girdle bands were open and without pores.

Remarks: —Our specimens are very similar to specimens identified as Pteroncola spp. from various locations ( Witkowski et al. 2000, Almandoz et al. 2014, Siqueiros Beltrones & Argumendo-Hernández 2014, Lobban 2015, Sunesen et al. 2015). It is distinctly different from P. carlinii , which has but one rimoportula ( Almandoz et al. 2014); but can be identified either as P. inane or P. marina ( Witkowski et al. 2000, Siqueiros Beltrones & Argumendo-Hernández 2014, Sunesen et al. 2015). Lobban (2015) briefly reviews taxonomic issues surrounding these two species.

Figures

FIGURES 62–64. Pteroncola cf.inane from culture UTKSA0078. 62. Whole valve exterior, face view. 63. Whole valve interior. 64. Valve and partly disassociated girdle bands. Girdle view.