Hyalosynedra cf. al-turkii J.S.M.Sabir & E.C.Theriot

Lobban, Christopher S. & Witkowski, Andrzej, 2023, Marine benthic diatoms of Guam: new records, Dictyoneis apapae sp. nov., and updates to the checklist, Micronesica 2023 (2), pp. 1-75 : 9

Hyalosynedra cf. al-turkii J.S.M.Sabir & E.C.Theriot

Ref. illus.: Navarro & Lobban 2009, figs 48–51 (as Hyalosynedra laevigata ); Sabir et al. (2018), figs 27–32

Samples: GU50D, GU52U-1

Dimensions: 35–40 µm long, 4–5 µm wide, 40 biseriate striae in 10 µm.

Diagnostics: Apex rounded; sternum lanceolate, narrow; ocellulimbus 6–8 pores wide.

Comments: This species is separated from H. prasadii by the dimensions according to the key in Sabir et al. (2018). Like that species, it has a lanceolate sternum, in contrast to other species in which the sternum is linear. The images published by Navarro & Lobban (2009) can be better identified as Sabir & Theriot’s new species, although the stria density is higher than their specimens. Hyalosynedra prasadii , or something like it, has also been noted in a few samples, but both species were scarce and detailed comparison with Red Sea and Florida species is not yet possible and, because of the fine discriminations needed, it is possible that these species are regional endemics and that our western Pacific species are different. We make this provisional record now only to point out that the record in Navarro & Lobbban (2009) is not H. laevigata . This genus needs more detailed study in our region but H. laevigata is present in our flora, see below.