Licmophora complanata Lobban

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 : 10

Licmophora complanata Lobban Figs 63, 64

Ref. illus.: Lobban 2021b, figs 1–25.

Samples: GU44AR-3

Dimensions: Length 135–143 µm, striae in 10 µm 9–10, increasing to 10–12 near apex.

Diagnostics: The apically oriented areolae, the triangular profile of the valve, always lying in girdle view, and the broad valvocopula with deep septum, together with apically elongated areolae, make this species unique so far even in LM.

Comments: Two specimens, including a complete frustule were found in LM. The apically elongated areolae are evident in both images; the three inflated areas are suggested by the focus and the short, intercalated striae ( Fig. 63 , black arrowheads), and the path of the midrib and septum are shown by arrow and arrowhead in Fig. 63 . The septum is very unusual in this species (Lobban 2021, fig. 19). Previously known only from Majuro, Marshall Islands.

Figures

Figures 63–64. Licmophora complanata, LM. Fig. 63. Valve with valvocopula (vc); very narrow valve with deep mantle, vc even deeper; long septum, mostly along the abvalvar edge of vc (arrow) except where it continues the arc over ligule (arrowhead) and toward base where it crosses to advalvar edge of vc. Fig. 64. Frustule in girdle view. Scale bars = 10 µm.