Mini review: Diatom species as seen through a molecular window

It has been accepted that we know less than 10% of the identified diversity in the marine microbial world and the diatoms are no exception. Even the species that we think we can easily recognize are often cryptic species, and even less is known of their life histories and spatial and temporal trends in their abundance and distribution. With new molecular and analytical techniques, we can advance our knowledge of a species to understand its morphological range, biogeographies and reproductive isolation. Moreover, some of molecular techniques are very sensitive. Depending on the species-level question(s) being asked, the molecular tools appropriate to answer them differ greatly.