Valve morphology of the marine diatom Neofragilaria nicobarica (Bacillariophyceae : Fragilariaceae)

Abstract

Valve morphology of Neofragilaria nicobarica Desik. et al. collected from the Andaman and Nicobar Islands (India) is studied with scanning electron microscope. The distinctive features of this diatom include the presence of apical slit fields, consisting of narrow slits, separated by longitudinal bars of silica, rather than rows of porelli, transverse striae with orderly rows of areolae that are not aligned across the sternum but alternate with each other, and the absence of rimoportulae. Its affinities are discussed.