Guide to Neofragilaria

Frustules rectangular in girdle view, with rounded valve/mantle interface. The valve is outline variable and may be linear, elliptic, or rhombic-anceolate to lanceolate. The apices are slightly produced to rounded, in larger specimens. The valve face is slightly arched and the mantle is usually steep. The valve is single-layered, with a thick sternum ornamented by fine granules on the valve exterior but not on the interior.

Spines, originating from robust virgae, may be present at the valve face/mantle junction. The striae are composed of large window-like areolae, which alternate, or are slightly offset giving the sternum a zig-zag appearance. There are two to three areolae on each side of the sternum: one areola on the valve face and one or two extending onto the mantle. Areolae are occluded by plate-like cribra, which are attached to virgae and/or vimines by small pegs. The cribra are situated close to the internal valve surface.

The valve apices may appear featureless in LM, but SEM shows an apical slit field to be present. Fine granules border both sides of each slit on the valve exterior, but are absent on the interior. Conical spines (up to 2) may be present between the apical slit field and the end of the sternum. Rimoportulae are absent.

The cingulum is composed of open, unperforated bands, with small granules on the exterior. Typically 2-3 bands are present in each epitheca and hypotheca.

Living cells typically possess 2 chloroplasts.

The cells are attached at edge of the valve face, forming either zig-zag or ribbon-like colonies. Attachment is facilitated by mucilage secreted from the apical slit fields. The spines of adjacent valves alternate with one another with the tip of each spine lying against a cribrum of the opposite valve.

Neofragilaria is a marine genus with 5 currently accepted species:
N. anomala (Giffen) Witkowski and Dabek
N. lineata (Giffen) Witkowski and Dąbek
N. stilus Krzywda, Witkowski and Chunlian Li
N. burchardtiae (Witkowski, Metzeltin and Lange-Bertalot) E.Morales
N. montgomeryii Ashworth and Chunlian Li

Neofragilaria nicobarica is considered a heterotypic synonym of N. anomala. Further study may expand the genus. The principal habitats for Neofragilaria are sand grains, coral boulders, and marine macroalgae.