Diatoms - Skeletonema
Skeletonema costatum (diameter 2-21 my) is one of the most common species in the coastal water of Norway. The small cells, only 7-15 my in diameter, join up to form long chains. Skeletonema is a centric diatom and is always studied from the side view. From the scales develop spines, which serve to unite the cells into straight chains. The long chains effective increases the friction against the water and decreases the rate of sinking. The reproduction, dividing of the cell, is measured in laboratory to two times pr day. That can explain the enormous increase in the biomass under the spring-bloom of phytoplankton in the sea. The circumstances have to be optimal with light, right temperature and nutrients, which give stability in the water mass, and sufficient nutrients, inclusive silicon concentration.
Vi ser alltid cellene fra siden, men sett fra bunn/lokk-siden er cellen rund og kiselstavene stikker ut langs periferien og knyttes til neste celle, lokk mot bunn. Skeletonema (tilhører de sentriske kiselalgene). Kiselstaver går fra lokk i en celle til bunnen i neste og dermed oppstår kjeder.
Bildet viser kjeden med større forstørrelse.