Parlibellus paschalis Lobban 2021, sp. nov.
Creators: name: Lobban, Christopher S.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Bacillariophyceae
Naviculales
Berkeleyaceae
Parlibellus
Parlibellus paschalis

description: <i>Parlibellus paschalis</i> Lobban, <i>sp. nov.</i> Figs 70–78. <b>Diagnosis:—</b> Differing from <i>P. delognei</i> (Van Heurck 1880: pl. 11) E.J. Cox 1988: 19 in lacking the cuniculus and pores in the central area and smaller size, and from <i>P. berkeleyi</i> (Kützing 1849: 106) E.J. Cox 1988: 21 in width and stria density. <b>Description:—</b> Tube-dwelling cells with plastids reminiscent of a hot cross bun in valve view, a butterfly in girdle view (Figs 70–72). Frustules, often remaining together after acid cleaning (Fig. 73), with numerous copulae (Fig. 74). Valves elliptico-lanceolate, 28–35 µm long, 10.5–12.5 µm wide (Figs 75–78). Striae 25–26 in 10 µm except slightly more distant (21 in 10 µm) in those adjacent to central area, weakly radiate in the central area, otherwise parallel, continuing around the apices (Figs 75–78). Striae punctate, the external areolae openings circular to transapically elongate, internally circular. Areolae closest to the raphe sternum somewhat more prominent (Fig. 77, arrow). Central area lacking isolated pores. External central raphe endings 4–6 striae apart, straight, extending into the narrowly oval central area, which as defined by the line of areolae is 11–12 striae long. External terminal raphe endings subapical (ca. 5 striae short of apex) with a small hook into a small hyaline area 1–2 striae wide. Internal raphe endings straight, a small helictoglossa at each terminus; no cuniculi at the central endings. <b>Holotype hic designatus:—</b> specimen at 16.1 mm E and 9.7 mm S of the mark on slide 192, deposited at ANSP, accession # ANSP-GC20094. Fig. 75. Registration: http://phycobank.org/102762. <b>Type locality:—</b> GUAM: Apra Harbor, GabGab reef, 13.443 N, 144.643 E, farmer fish (<i>Plectroglyphidodon lacrimatus</i>) territory 7–8 m depth, sample GU44L-C. <i>C.S. Lobban and M. Schefter, 2 March 2008</i>. <b>Etymology:—</b> <i>paschalis</i>, L. adjective referring to Easter, with reference to the resemblance of the live cells in valve view to the Eastertime bakery item, hot cross buns. <b>Additional Records:—</b> GUAM: GabGab reef, Apra Harbor, GU44I-2!, GU44K-6!. <b>Comments:—</b> This species is most like <i>P. delognei</i> f. <i>elliptica</i> (Lobban 1983: 287) Cox 1988: 21 but differs in lacking the cuniculus that is characteristic of both forms of <i>delognei</i>, along with associated pores in the central area. [A cuniculus (Ross <i>et al.</i> 1979, Cox 1978) “comprises a simple pore in the external central area connecting with an elongate perforate raised structure terminating the internal raphe fissures in the central area.”] It is also shorter and narrower than that form, though wider than <i>P. berkeleyi.</i> The colony structure is similar to the narrow threads of the nominate variety of <i>P. delognei</i> but much different from the large, cold-water colonies of var. <i>elliptica</i> (Cox 1988, Lobban 1983). The stria density is higher than other similar species (Table 2), including <i>P. berkeleyi</i> (16–18 in 10 µm).
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 pages 251-252, DOI: 10.11646/phytotaxa.508.3.1, http://zenodo.org/record/5425968
description: {"references": ["Van Heurck, H. (1880) Synopsis des Diatomees de Belgique Atlas. Anvers: Ducaju et Cie. pls I - XXX [pls 1 - 30].", "Cox, E. J. (1988) Taxonomic studies on the diatom genus Navicula. V. The establishment of Parlibellus gen. nov. for some members of Navicula sect. Microstigmaticae. Diatom Research 3: 9 - 38. https: // doi. org / 10.1080 / 0269249 X. 1988.9705014", "Kutzing, F. T. (1849) Species algarum. pp. [i] - vi, [1] - 922. Lipsiae [Leipzig]: F. A. Brockhaus.", "Lobban, C. S. (1983) Colony and frustule morphology of three tube-dwelling diatoms from eastern Canada. Journal of Phycology 19: 281 - 289. https: // doi. org / 10.1111 / j. 0022 - 3646.1983.00281. x", "Ross, R., Cox, E. J., Karayeva, N. I., Mann, D. G., Paddock, T. B. B., Simonsen, R. &amp; Sims, P. A. (1979) An amended terminology for the siliceous components of the diatom cell. Nova Hedwigia Beihefte 64: 513 - 533.", "Cox, E. J. (1978) Taxonomic studies on the diatom genus Navicula Bory. Navicula grevillii (C. A. Ag.) Heiberg and N. comoides (Dillwyn) H. &amp; M. Peragallo. Botanical Journal of the Linnaean Society 76: 127 - 143. https: // doi. org / 10.1111 / j. 1095 - 8339.1978. tb 01502. x"]}