Eucocconeis Guide
Credit: Marina Potapova, Eduardo Morales
  1. Frustules heterovalvar - one valve with a raphe, the other lacking a raphe
  2. Frustules with torsional twist about the apical axis
  3. Valves linear-elliptic to lanceolate
  4. Striae uniseriate
  5. Terminal raphe fissures long, curved to opposite sides

Eucconeis frustules are bent about the median transapical plane, including a twisted, sigmoid central sternum. As a member of the monoraphid group, the frustules are heterovalvar and differ in ornamentation between the raphe valve and rapheless valve.

Eucocconeis species occur commonly in the littoral zone of oligotrophic lakes, within epipelic, epipsammic, or epilithic habitats. Some species occur on wet walls.