Sirodotia cryptica Necchi, N.L.Rossignolo & M.O.Paiano, 2021

Rossignolo, Natalia L., Vis, Morgan L., Paiano, Monica O., Eloranta, Pertti, West, John A., Ganesan, E. K., Yasmin, Farishta, Lim, Phaik-Eem & Necchi, Orlando Jr, 2021, Revision of the genus Sirodotia Kylin (Batrachospermales, Rhodophyta) with description of four new species, Cryptogamie, Algologie 20 (8), pp. 93-127 : 104

Sirodotia cryptica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov.

( Fig. 4 F-J)

TYPE. — F. R. Borges, 15.IV.2014, ( SJRP [ SJRP 32575]).

TYPE LOCALITY. — Brazil, Goiás, Highway GO-070, between the municipalities of Jussara and Itaberaí ; 16°00’32.7”S, 48°55’55.9”W .

ADDITIONAL SPECIMENS EXAMINED. — SJRP 31923 and SJRP 31925 ( Appendix 1).

ETYMOLOGY. — The species epithet indicates that the alga is cryptic with another species described in this study ( S. amazonica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov.).

DISTRIBUTION. — South America, Brazil (midwestern).

REPRESENTATIVE DNA SEQUENCES. — COI-5P ( KF010488 , KF010491 , MW053463 ,), rbc L ( KC951865 , KC951869 , MW053479 ) and LSU ( MW053494 , MW053495 , MW053498 ).

Description

Plants monoecious or dioecious; whorls 223-559 µm in diameter; primary fascicles (4-)5-10(-11) cells; proximal cells cylindrical or ellipsoidal; distal cells spherical, ellipsoidal or obovoidal; secondary fascicles abundant, covering the entire internode; spermatangia spherical or obovoidal, 1-3 in a group, few or abundant on primary or secondary fascicles, 6-9 µm in diameter; carpogonial branches composed of 1-4 disc- or barrel shaped cells, arising from periaxial, proximal or median cells of primary fascicles, rarely on the secondary fascicles or cortical filaments, short, 10-25 µm long; carpogonia with sessile, elongate cylindrical (with wavy margins), elongate-conical or fusiform trichogynes, sometimes with anomalous shapes (bent end), (24-)26-58 µm in length, 9-13(-15) µm in diameter; gonimoblast initial developing from the protuberant side of the carpogonium; gonimoblast filaments prostrate with erect branches of 2-5 cells; carposporangia subspherical, ellipsoidal or obovoidal, 10-17 µm in length, (7-)8-11 µm in diameter.

Remarks

This species is morphologically indistinguishable from S. amazonica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov. that also occurs in Brazil, but is genetically divergence and thus, it is here described as a new species.

Figures

FIG. 4. – Morphological features of Sirodotia species.A-E, Sirodotia assamica Necchi,Rossignolo,Yasmin,J.A.West & Ganesan (photos taken from samples SJRP 32583,32584):A, B; primary fascicles with spermatangia in clusters (arrows); C, a carpogonium with a mature trichogyne (arrow) showing the basal hemispherical protuberance (arrowhead); D, fertilized carpogonium with attached spermatium (arrow), gonimoblast initial (arrowhead) developing from the same side of the basal protuberance (arrowhead); E, carposporangia (arrow), prostrate (arrowhead) and erect (double arrowhead) gonimoblast filaments; F-J, Sirodotia cryptica Necchi, N.L.Rossignolo & M.O.Paiano, sp. nov. (photos taken from sample SJRP 32575 - holotype): F, obconical whorls; G, primary fascicle with spermatangia (arrow); H, carpogonium with a mature cylindrical trichogyne (arrow) showing the basal hemispherical protuberance (arrowhead); I, fertilized carpogonium with a sessile elongate-conical trichogyne (arrowhead), attached spermatium (arrow) and gonimoblast initial developing from the protuberant side of the carpogonial base (double arrowhead); J, carposporangia (arrows) and erect gonimoblast filaments (arrowheads). Scale bars: A, B, G, 50 μm; C, D, H-J, 20 μm; E 10 μm; F, 200 μm. B-D, reproduced with permission from Rossignolo et al. (2020) (Magnolia Press).