Young ISDR

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...

In this first 2019 Diatom of the Month post , Chetan Chandrakant Gaonkar *  present us the marine diatom planktonic family Chaetocerotaceae and how to unravel its complex diversity by using up-to-date molecular techniques The family  Chaetocerotaceae   is arguably among the most diverse among planktonic diatoms. Species are particularly common in coastal waters and  upwelling zones   where they are responsible for a substantial part of the primary productivity 1-3 . The hallmark of this family constitutes hollow siliceous tubular structures, called the setae, emerging from the corner of the valves. The family includes two extant genera,  Bacteriastrum  Shadbolt and  Chaetoceros  Ehrenberg 4 , the latter being way more diverse. Within the genus  Chaetoceros  two subgenera are commonly recognized,  Chaetoceros  (a.k.a.  Phaeoceros), which is characterized by exhibiting plastids in the  setae , and  Hyalo...