Actinotaenium mooreanum (W.Archer) Teiling (1954: 408)

Ramos, Geraldo José Peixoto, Bicudo, Carlos Eduardo De Mattos & Moura, Carlos Wallace Do Nascimento, 2018, Some new, rare and interesting desmids from bromeliad phytotelmata in Brazil, Phytotaxa 346 (1), pp. 59-77 : 60

Actinotaenium mooreanum (W.Archer) Teiling (1954: 408) ( Figs 68–72 )

Cells solitary, approximately 2 times longer than wide, widely elliptic, apices widely rounded; chloroplast stellate, two pyrenoids; zygospore subrectangular, dark brown, with rounded-acuminate papillae. Cells 16–20 μm long, 8–9 μm wide; zygospore 17–22 μm long, 11–14 μm wide.

Material examined: BRAZIL, Bahia, Santa Teresinha, Serra da Jiboia. 14-I-2015, G. J. P. Ramos et al. s/n ( HUEFS 224661), 18-VII-2015, G. J. P. Ramos et al. s/n ( HUEFS 224679), 11-IX-2015, G. J. P. Ramos et al. s/n ( HUEFS 224705), 20-XI-2015, G. J. P. Ramos et al. s/n ( HUEFS 224721).

Habitat: bromeliad tanks ( Alcantarea nahoumii ); T 26.1 (± 3.9 ºC). pH 5.9 (± 0.6). C 0.24 (± 0.18 mS. cm-1). TDS 0.11 (± 0.09 ppt). DO 6.4 (± 0.8 mg.L- 1).

Notes: Actinotaenium mooreanum is reported here for the first time for South America; with previous records only from Europe and Oceania ( Guiry & Guiry 2017). During our analysis, we commonly found zygospores of this species—usually in groups associated with the mucilaginous sheaths of cyanobacteria. According to Růžička (1981), this species prefers slightly acidic to neutral environments (pH 4.9–7.5), similar to conditions found in bromeliad tanks.

Figures

FIGURES 49–72. Docidium baculum: LM (49–50); SEM (51), ventral view (49) and the isthmus details (50–51); Euastrum quadriceps: LM (52–56); SEM (57), lateral view (52), ventral view (53, 57), apical view (54–56); Euastrum luetkemuelleri var. carniolicum: LM (58– 65) SEM (66–67), ventral view (58–60, 66), diagonal view (67), lateral view (61), apical view (62–63), zygospores (64–65); Actinotaenium mooreanum: LM (68–69, 71–72) SEM (70), ventral view (68–670) and zygospores (71–72). Scale bars 10 μm (Figs 42–59, 62–66), 5 μm (Figs 60–61). Scale bar 10 μm (49–65, 68–72), 5 μm (66–67).