Denticula Guide Revised
Credit: Pat Kociolek, Nina Desianti, Ian Bishop
  1. Raphe eccentric, on a wide, low marginal keel
  2. Internal fibulae distinct, thickened

The raphe system of each valve is positioned diagonally opposite to one another, demonstrating nitzschiod symmetry. The raphe system is located within a wide, low keel. The raphe may or may not have proximal raphe ends or be continuous across the valve, a feature difficult to see without SEM. Thick internal bars of silica (fibulae) are present and parallel to the striae. The fibulae widen near the valve margins to form a 'tooth-like' appearance, hence the genus name Denticula.

Denticula species occur in rather diverse habitats. Some species may be locally abundant in carbonate rich waters of moderate conductivity. The genus also contains species characteristic of large oligotrophic lakes, as well as warm springs.