Incendia yoneshigueana E. M. S. Pestana, G. N. Santos, Cassano & J. M. C. Nunes, 2020

Pestana, Edilene Maria Dos Santos, Lyra, Goia De Mattos, Santos, Gabriel Do Nascimento, Santos, Cibele Conceição Dos, Cassano, Valéria & Nunes, José Marcos De Castro, 2020, Integrative approach reveals underestimated Peyssonneliales diversity in Brazil: registering the first occurrence of Ramicrusta and Incendia, with the description of three new species, Phytotaxa 439 (1), pp. 39-55 : 42-43

Incendia yoneshigueana E. M. S. Pestana, G. N. Santos, Cassano & J. M. C. Nunes sp. nov. ( Fig. 1 A-D).

Diagnosis: — Thallus crustose, prostrate and completely adherent to the substratum by multicellular rhizoids. Radial cellular projections with secondary pit connections in the lower perithallus immediately above to hypothallial cells. Hair cells absent. Distinguished from other species of the genus by rbc L sequence divergence above 7.9%.

Type:— BRAZIL. Bahia: Maraú, Algodões, 14º04’15,06”S – 38º57’32,05”W, 29 September 2015, E. M. S. Pestana, G.N. Santos & J.M.C. Nunes ( ALCB 129839). GenBank accession number for COI-5 P MN 990086, rbc L MN 990099.

Etymology: — Named in honor of Dr.Yocie Yoneshigue-Valentin for her contributions to the taxonomy of Peyssonneliales in Brazil.

Description: — Thallus reddish pink, lacking concentric rings in margin portion ( Fig. 1A ). Blades are lobed, completely adherent to the substratum, 350–430 μm, however, easily removed. Dorsal thallus surface frequently giving rise to blister-like overgrowing blades ( Fig. 1A ). Rhizoids are multicellular, 80–135 μm long and 7–10 μm diameter, formed of 3–4 cells. Basal cells in the rhizoids are partially embedded in a hypobasal cuticle ( Fig. 1D ). Hypothallus is monostromatic, the hypothallial filaments are parallel, comprised of irregular rounded cells, each giving rise (45º) to one perithallial filament ( Fig. 1B ). Secondary pit connections ( Fig. 1E ) connect radial cellular projections ( Fig. 1F ) to cells of adjacent assurgent filaments in the lower perithallus. Cells of the assurgent perithallus are regularly arranged and composed by regular rectangular cells intercalated by rounded cells in the upper perithallus ( Fig. 1C ). Hair cells absent. Gametangia and tetrasporangia were not observed in the present study.

Habitat: — Epilithic specimen collected in the lower-intertidal in protected areas of the reef, emergent during low tide periods.

Incendia is distinguished by a combination of characters, including the presence of secondary pit connections and multicellular rhizoids ( Dixon & Saunders 2013). Incendia yoneshigueana can be separated from other species of the genus, with the exception of Incendia glabra , by the absence of hair cells at the apex of the perithallus; however, it is distinguished from the latter by the shape and arrangement of radial cellular projections in the lower perithallus. A comparison of the morphological characteristics for Incendia species is shown in Table 1.

Figures

FIGURE 1. Incendia yoneshigueana. (A) Habit. (B) Radial vertical section of thallus, evidencing perithallus. (C) Upper perithallus. (D) Multicellular rhizoids. Basal cell partially embedded in hypobasal cuticle (arrows). (E) Radial cellular projections in lower perithallus connected by secondary pit connections (arrows). (F) Radial cellular projections in lower perithallus (arrows). Scale bar: A, 1 cm; B, 100 μm; C, D, E and F, 30 μm.