Diatom of the Month March 2019 - The hidden diversity of small-sized araphid diatoms
by Chunlian Li* What we've got here? Chunlian Li presents her latest research, and how different small araphid diatoms are when we look at them more closely Small-celled araphid diatoms (bilaterally symmetrical diatoms without a slit on the valve face, and with diameter s < 20 mm) are important contributors to primary production in marine and freshwater habitats (Round et al . 1990; Witkowski et al . 2000 ). These diatoms mainly colonize benthic substrates, e.g. epiphytic (plants), epizoic (animals) or epipsammic (sand) habitats (Fig. 1) and are often the most diverse benthic algae. Yet, benthic habitats are relatively under-sampled possibly because of their higher heterogeneity than open water habitats, which results in poorly described araphid diatom floras. In addition , the identification of these diatoms is difficult, even for the most experienced diatomists, because of their small size and the scarcity of reliable diagnostic characters. Fig...