Serratifera andersonii Chunlian Li, Dąbek & Wachnika

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 : 15

Serratifera andersonii Chunlian Li, Dąbek & Wachnika Figs 94, 95

Ref. illus.: C. Li et al. 2018, p. 63, figs 360–373

Sample: GU26A

Dimensions: Length 5.5–9.2 µm, width 2.3 µm, striae 15 in 10 µm

Diagnostics: Small, clavate (heteropolar), with a clear pore field at one pole, simple, stick-like spines arising from areolae, whereas in S. rhombica there are “accessory” spines flanking the larger central spines (C. Li et al. 2018).

Comments: Many small Fragilariaceae have been studied recently, incorporating much debate on generic boundaries. Serratifera Ashworth, Chunlian Li & Witkowski (in C. Li et al. 2016) was established largely on molecular grounds and emended on morphological grounds by the same authors (in C. Li et al. 2018). Morales et al. (2019: 274) argued against the new genus and for inclusion of its species in the older genus Pseudostaurosira D.M.Williams & Round. Witkowski did not accept the argument (personal communication during ms. preparation), so we have presented this and the next species under their original names. Morales et al. transferred them to Pseudostaurosira andersonii (S.Sato, Chunlian Li & Witkowski) E.A.Morales, Novais & C.E.Wetzel , and P. rhombica (S.Sato, Chunlian Li & Witkowski) E.A.Morales, Novais & C.E.Wetzel , respectively. The senior author cannot contribute to this debate. All small Fragillariaceae are rare in our Guam samples to date, probably because the frustules are washing in from their primary habitats (mostly sediments and biofilms).

Figures

Figures 91–97. Pseudictyota and Serratifera, SEM except Fig. 91. Figs 91–93. Pseudictyota bicorne. Fig. 91. Frustule in girdle view, stacked focal planes. Figs 92, 93. Valve view in SEM and detail of pseudoloculi. Figs. 94, 95. Serratifera andersonii frustules in valve and girdle view. Figs. 96, 97. Serratifera rhombica frustules in valve and girdle view. Scale bars: Fig. 91 = 10 µm, Fig. 92 = 15 µm, Fig. 93 = 5 µm, Figs 94–97 = 2 µm.