Lyrella hennedyi (W. Sm.) Stickle & D.G. Mann

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 : 27

Lyrella hennedyi (W. Sm.) Stickle & D.G. Mann in Round et al. (1990: 672) ( Figs 75–79 )

Basionym: Navicula hennedyi W. Sm. (1856: 93)

Lyrella hennedyi (W. Sm.) Guslyakov & Karayeva (1992: 34, pl. 47, figs 2, 3 nom. invalid)

Valves broadly elliptic with cuneate, broadly to obtusely rounded apices, length 25–140 µm, breadth 15–65 µm. Raphe straight, external central endings expanded, distant, axial area narrow linear, close to central area widened lanceolate, central area transversely rectangular, connected to lateral areas. Lateral areas relatively large, semi-elliptic to semi-lanceolate, encompassing 1/3 to more than 1/2 of the valve width, marked by obscure, granulate prolongations of transapical striae. Transapical striae developed in the marginal part of the valve, slightly radiate, 9–11 in 10 µm, areolae 9–20 in 10 µm.

Lyrella hennedyi f. granulata sensu Hustedt (1961 –1966: 458, figs 1519 a–c) has to be transferred into the species rank because of the much narrower lateral areas, different valve outlines and different external central raphe ends. Lyrella hennedyi f. cuneata (A. Schmidt) Ryabushko (2006: 61) and other infraspecific taxa may also require further analysis.

Distribution:—Marine species widespread (cosmopolitan) in coastal areas, entering also the western Baltic Sea ( Witkowski et al. 2000). Black Sea, Bulgarian coast ( Temniskova-Topalova & Petrova-Karadjova 1998), Romanian coast ( Bodeanu 1987 –1988, Caraus 2002); North-western region ( Ryabushko 1991, Guslyakov & Nevrova 1998, Guslyakov 2002), Crimean coast ( Proshkina-Lavrenko 1963a, Kucherova 1973, Guslyakov & Nevrova 1998, Nevrova 1999a, Ryabushko 2001, Nevrova & Revkov 2003, Senichkina et al. 2004, Nevrova 2008) and Caucasian coast ( Proshkina-Lavrenko 1963a, Nevrova 1999b).

Literature:— W. Smith (1856: 93); Hustedt (1961 –1966: 453, fig. 1516); Round et al. (1990: 672); Guslyakov et al. (1992: 34, pl. 47, figs 2, 3).

Figures

FIGURES 75–80: Lyrella hennedyi. Figs 75–77: Valve view, LM, scale bar = 10 µm. Fig. 78: Internal view, note the relatively narrow elevated, structureless lyrate lateral areas being relief-like, elevated above internal valve surface with dispersed areolae, SEM, scale bar = 7 µm. Specimens from the Black Sea (Laspi Bay, Vitino coast, Phyllophorae Field, Dvujakornaya Bay). Fig. 79: Navicula hennedyi, specimen from BM 23529; scale bar = 10 µm. Fig. 80: photograph of the type slide BM 23529.