Hyalosynedra, 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

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 : 16

Hyalosynedra al-turkii Sabir and Theriot sp. nov. ( Figs 27–32 )

Holotype:— ANSP G.C. 38098

Isotypes: — SA 28 in the Theriot collection at UT Austin.

Type locality: —Subtidal sediment adjacent to a fishing dock in the Corniche area of Jeddah, Kingdom of Saudi Arabia (21° 36.10’ N, 39° 06.37’ E).

Material studied: —Wild and cultured ( UTKSA 0076) material originating from the type locality: SA 28, a collection by turkey baster of subtidal sediment in the Corniche area of Jeddah, Kingdom of Saudi Arabia (21° 36.10’ N, 39° 06.37’ E).

Description: —This was observed to be a relatively small-sized species of Hyalosynedra , with measured specimens 29.6–47.6 μm in length and 2.6–3.5 μm in width ( Figs 27, 28, 31 ). The margins were mostly continuously convex, converging to a rounded apex, with a few specimens with a weak concave curvature near the apex (but not sufficient to cause the end to appear capitate: Figs. 27–32 ). Sterni were weakly lanceolate to linear. There was an asymmetric rimoportula at each pole. 48–54 virgae in 10 μm, with biseriate striae. Ocellulimbi were weakly to strongly sunken ( Figs 29, 30 ), 6–8 pores wide and 3 pores tall, with 7–10 pores per 1 μm, and 2–5 very small spines or bumps at the top externally. Girdle bands were dissociated from one another and the valves in the cleaned cultured material, but all girdle bands found were without pores and all were open (not illustrated).

Remarks: —The apices of H. al-turkii differed from those of H. hyalina and H. laevigata by having tapering rather than capitate or subcapitate apices. The sternum of the molecularly closely related H. laevigata was also often more strongly lanceolate (cf., Figs. 20 , 27 )

Etymology: —This species was named in honor of Prof. Dr. Yusuf Abdulaziz Al-Turki, Vice President for Graduate Studies and Scientific Research, King Abdulaziz University (KAU). His support for this project has been essential to its success.

Figures

FIGURES 27–32. Hyalosynedra al-turkii from culture UTKSA 0076. 27. Differential interference contrast LM of entire valve. 28. SEM exterior of entire valve. 29. SEM of apex of specimen with very weakly sunken ocellulimbus. 30. SEM of specimen with more deeply sunken ocellulimbus. 31. SEM interior of entire valve. 32. SEM interior detail of apex.

FIGURES 20–26. Hyalosynedra sublaevigata from HK512, Puerto Rico. 20. LM of specimen with somewhat protracted or weakly concave margin before capitate end. 21. LM of specimen with margin concave to capitate end. 22. SEM of specimen with margins near linear from center to end. 23. SEM detail of apex. 24. SEM detail of broad central area of lanceolate sternum. 25. SEM interior of entire valve. 26. SEM detail of interior of apex showing asymmetrical rimoportula.