Species Description: Valves are straight and lanceolate with very long, slender rostrate apices (Fig. 1, entire valve interior, SEM). These apices may be of unequal or equal length (Fig. 3, living cell, phase contrast). The raphe is strongly excentric; the interstriae are transverse, diminishing to single areolae in the rostrate apices (Fig. 2, detail of Fig. 1). Valve length is about 145-160µm and width is 8-10µm. The interstriae number about 34 in 10µm. Fibulae subtending the raphe are 7-10 in 10µm, slightly more numerous in the rostrate apices (Fig. 2). Irregularly spaced ribs traverse the valve interior, averaging about 10 in 10µm.
Witkowski et al. (2000) give a much broader range of metrics for this species, but the IRL examples are similar to those reported from the IRL by Navarro (1982) and from Guam by Lobban et al. (2012). It was rare in the IRL, usually in the southern areas, which is consistent with being described as a “warm water” species.
Lobban CS, Schefter M, Jordan RW, Arai Y, Sasaki A, Theriot EC, Ashworth M, Ruck EC, Pennisi C. 2012. Coral-reef diatoms (Bacillariophyceae) from Guam: new records and preliminary checklist, with emphasis on epiphytic species from farmer-fish territories. Micronesica 43: 237-479.
Navarro JN. 1982. Marine diatoms associated with mangrove prop roots in the Indian River, Florida, U.S.A. Biblio Phycol 61: 1-151.
Witkowski A, Lange-Bertalot H, Metzeltin D. 2000. Diatom Flora of Marine Coasts I. Iconographia Diatomologica 7: 1-925.