Hyalosynedra laevigata (Grunow) Williams & Round, 1986

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

Hyalosynedra laevigata (Grunow) Williams & Round Figs 59–62

Ref. illus.: Sabir et al. 2018, p. 7, figs 2–16. Non Navarro & Lobban 2009, figs 48–51.

Samples: GU44Z-15, GU58G-4A

Dimensions: length 114–132 µm, width 5–6 µm.

Diagnostics: Long, lanceolate, hyaline cells, apices rounded to weakly capitate; linear midrib visible in LM; pseudocellus with three rows of pores; rimoportulae asymmetrical.

Comments: Differing from H. lanceolata Belando, Jiménez & Aboal , which has a broad, lanceolate sternum. It is so similar in size and shape to Stricosus cardinalii E.C.Theriot & Lobban (see below) that the two taxa can scarcely be distinguished in LM. In SEM, the character of the rimoportulae and the depth of the pseudocellus separate them. See also comments above on H. cf. al-turkii .

Figures

Figures 59–62. Hyalosynedra laevigata. Figs 59, 62. External view and detail of apex showing hyaline tip beyond the rimoportula opening (arrow) and the three rows of pores in the ocellulimbus. Figs 60, 61. Internal view with detail of apex showing character of the rimoportula (arrow). Scale bars: Figs 59, 60 = 10 µm, Fig. 61 = 2 µm, Fig. 62 = 1 µm.