Divergita decipiens Lobban 2021, sp. nov.
Creators: name: Lobban, Christopher S.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Bacillariophyceae
Licmophorales
Ulnariaceae
Divergita
Divergita decipiens

description: <i>Divergita decipiens</i> Lobban, <i>sp. nov.</i> Figs 29–32. <b>Diagnosis:—</b> Differing from <i>D. biformis</i> in striae on valve face comprising irregular, transapically oval areolae with wide virgae, and in having a prominent, lanceolate sternum. <b>Description:—</b> Valves straight, 94 µm long, 4 µm wide, lanceolate with weakly capitate apices (Figs 29, 30, 32). Striae 28 in 10 µm, decussate on margin becoming uniseriate on valve face with generally three narrow, irregular, transapically elongated areolae, separated by wide virgae compared to <i>D. biformis</i> (Figs 30, 31). Sternum broad and lanceolate. A hyaline area at each apex with a rimoportula in each. Internally, the rimoportulae asymmetrical and a line of foramina along each boundary between valve face and mantle (Fig. 32). <b>Holotype hic designatus:—</b> Figs 29–31 from stub 566 (GUAM diatom herbarium, catalog # 700566), according to Article 40.5 of the International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) (Turland <i>et al</i>. 2018). Registration: http://phycobank.org/102757. <b>Type locality:—</b> GUAM: Apra Harbor, Outhouse Beach, 13.464 N, 144.656 E, in algal turf from farmer fish (<i>Stegastes nigricans</i>) territory, ca. 3 m deep, sample GU52R-2. <i>C.S. Lobban and M. Schefter, 24 July 2013</i> <i>.</i> <b>Etymology:—</b> Named for its deceptive similarity to <i>D. biformis</i>. <b>Comments:—</b> This species was initially confounded with <i>D. biformis</i>, because length and stria densities are very similar. However, given the use of sternum characters to distinguish species in the related genus <i>Hyalosynedra</i> (Sabir <i>et al.</i> 2018), the broader, lanceolate sternum here, combined with the different appearance of areolae on the valve face, marked <i>D. decipiens</i> as a separate species, and required that both be typified by SEM images. This species seems slightly narrower than <i>D. biformis</i> (compare Figs. 26, 29) but several other specimens from Guam with some further variation in characters have been left unidentified for the present. It is likely that there is more diversity in <i>Divergita</i> to be discovered through SEM surveys of coral reef samples. It is possible that the rarity of these specimens is because they are being deposited into the samples from elsewhere (planktonic?), rather than growing in the farmer fish territories.
description: Published as part of <i>Lobban, Christopher S., 2021, New species of benthic marine diatoms (Bacillariophyta) from the Western Pacific islands of Guam and Yap, pp. 235-265 in Phytotaxa 508 (3)</i> on page 242, DOI: 10.11646/phytotaxa.508.3.1, http://zenodo.org/record/5425968
description: {"references": ["Turland, N. J., Wiersema, J. H., Barrie, F. R., Greuter, W., Hawksworth, D. L., Herendeen, P. S., Knapp, S., Kusber, W. - H., Li, D. - Z., Marhold, K., May, T. W., McNeill, J., Monro, A. M., Prado, J., Price, M. J. &amp; Smith, G. F. (Eds.) (2018) International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress Shenzhen, China, July 2017. Regnum Vegetabile 159. Glashutten: Koeltz Botanical Books. https: // doi. org / 10.12705 / Code. 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. &amp; Ashworth, M. P. (2018) Systematics of araphid diatoms with asymmetric rimoportulae or densely packed virgae, with particular attention to Hyalosynedra (Ulnariaceae, Bacillariophyta). Phytotaxa 347: 1 - 49. https: // doi. org / 10.11646 / phytotaxa. 347.1.1"]}