Lindavia ocellata

Valves are circular with a central area spanning 1/3-2/3 of the valve face, surrounded by alveolate striae of varying length. The central area is ornate with orbiculi depressi and complementary elevated papillae, each occurring 2-6 per valve. The central area is often smooth, but it can be colliculate. Alveolate striae open externally via small areolae arranged in multiseriate rows. The rows comprise 1-2 radial striae of small areolae between 2 striae composed of larger areolae. Alveolae open internally though a large circular to oval foramen at the valve face/mantle junction. The number of fascicles per valve is 35-75, with a relation to valve size. Fascicle count is related to valve diameter (total fascicle count = 2.94 * (diameter) + 27.1). For example: (diameter, total fascicles); 15,68; 6.3,42; 3.7,35. Fascicles are separated internally by costae that occasionally branch with new rows of fascicles between the branches. One to 3 central fultoportulae occur near the orbicular depressions, with simple round external openings. Marginal fultoportulae occur every 4–5 costae. A single rimoportula occurs on a costae. A ring of spinules is present along the valve face/mantle junction and may have additional small conic spines scattered beneath.

Lindavia ocellata is part of a species complex comprising L. polymorpha, L. rossii, L. kuetzingiana, and their allies (Håkansson 2002). These species are often sympatric and may have no apparent morphological differences (Knie and Hübener 2007), therefore they may be indistinguishable in LM. The species share similar ornamentation in the central area. Traditionally, L. ocellata is thought to have only three orbiculi depressi and papillae, however several studies have shown the number of orbiculi depressi and papillae to be 2 to 6, the central area to vary from smooth to colliculate and a variable relative diameter of the central area (Kiss et al. 1999, Dudela 2016). Using combinations of the number of orbiculi depressi, central area size, and central area shape, Cvetkoska et al. (2012) distinguished 22 morphotypes of L. ocellata from a sediment core of Lake Ochrid, Macedonia. The range of valve sizes is high in L. ocellata. Edlund et al. (2003) observed valves from 2.5 to 43 µm diameter and a wide and multimodal range of initial valve size (9-43 µm) within a single L. ocellata population (Lake Hövsgöl, Mongolia), extending the known size range of L. ocellata. Genkal and Popovskaya (2008) similarly found different sized subpopulations of L. ocellata in the same lake.