Lyrella barbara (Heiden) D. G. Mann, 1990

Nevrova, Elena, Witkowski, Andrzej, Kulikovskiy, Maxim, Lange-Bertalot, Horst & Kociolek, J. Patrick, 2013, A revision of the diatom genus Lyrella Karayeva (Bacillariophyta: Lyrellaceae) from the Black Sea, with descriptions of five new species, Phytotaxa 83 (1), pp. 1-38 : 14-19

Lyrella barbara (Heiden in Heiden & Kolbe) D.G. Mann in Round et al. (1990: 671) ( Figs 44–49 )

Valves broadly circular-elliptic to lanceolate with cuneate shortly rostrate apices, length 36–70 µm, breadth 28–35 µm. Raphe straight, external central endings relatively distant, axial area narrow linear, central area small, narrow, transversely rectangular, connected to lanceolate lateral areas. Lateral areas show the obscured prolongation of transapical striation, narrow in the middle, weakly constricted, narrowed towards apices, terminating below apices. Transapical striae punctate, in the middle parallel towards apices becoming radiate, 10 in 10 µm, areolae 20 in 10 µm.

Distribution:—marine species, frequent in the southern hemisphere ( Simonsen 1992: 53; Witkowski et al. 2000: 231); Black Sea, Crimean coast (Omega Bay, Balaklava Bay) ( Nevrova 2010); recorded for the first time in the Black Sea diatom assemblages.

Literature:— Heiden & Kolbe (1928: 617, pl. 3, fig. 61); Hustedt (1961 –1966: 473, fig. 1531); Simonsen (1992: 52, pl. 53, figs 1–4).

Lyrella fogedii Witkowski, Lange-Bert. et Metzeltin (2000: 233, pl. 99, figs 4–7, pl. 100, figs 1–3) ( Figs 72–74 )

Navicula aestimata Hust. sensu Foged (1975: 35 , pl. 22, fig. 13–15)

Valves circular-elliptic with broadly rounded apices, length 23–30 µm, breadth 16–18 µm. Raphe straight, external central endings large, triangular, axial area narrow, central area transversely rectangular, connected to lateral areas. Lateral areas lanceolate, bearing transverse markings. Transapical striae punctate, in the middle parallel, towards apices becoming radiate, 17–19 in 10 µm.

Distribution:—Previously known only from the type locality (littoral of the Indian Ocean, Dar es Salaam, Tanzania) ( Witkowski et al. 2000); Black Sea, Crimean coast (Laspi Bay, Omega Bay, Balaklava Bay) ( Nevrova 2010); recorded for the first time in the Black Sea diatom assemblages.

Literature:— Foged (1975: 35, pl. 22, figs 13–15); Witkowski et al. (2000: 233, pl. 99, figs 4–7, pl. 100, figs 1–3).

Figures

FIGURES 44–49. Lyrella barbara. Figs 44–47: Valve view, LM, scale bar = 10 µm. Fig. 48: External view, note girdle bands bearing a single row of areolae and fine structure of lateral areas, SEM, scale bar = 10 µm. Fig. 49: Internal view, note occlusions of areolae irregular in shape, and structureless internal surface of lateral areas, SEM, scale bar = 10 µm. Specimens from the Black Sea (Balaklava Bay, Omega Bay, Cape Feolent).

FIGURES 68–74: Figs 68–70: Lyrella clavata, valve view, LM, scale bar = 10 µm. Specimens from the Black Sea (Omega Bay, Laspi Bay). Fig. 71: reproduction of line-drawing published by Schmidt et al. (1874–1959: pl. 3, fig. 13, as Navicula clavata var. elliptica), scale bar = 10 µm. Figs 72, 73: Lyrella fogedii, valve view, LM, scale bar = 10 µm. Fig. 74: Lyrella cf. fogedii, SEM, external view, scale bar = 8 µm. Specimens from the Black Sea (Balaklava Bay, Omega Bay, Laspi Bay).