Diatom

No direct toxic effects have been observed but C. wailesii produces large amounts of mucilage which, at high cell densities, which can clog up fishing gear and smother the seabed.

The shape and extent of the central hyaline area is variable. It can be very small and surrounded by a ring of larger areolae.

Cells are often as high as wide, cells are rectangular in outline or with an undulating upper valve edge, depending on the focal plane. In girdle view a prominent hyaline area at the centre of the valve with wide interstrae radiating from it resulting in an irregular fasciculation. Areolae are small. Cribra visible with LM. There are two marginal rings of processes.

Cells are often as high as wide, cells are rectangular in outline or with an undulating upper valve edge, depending on the focal plane. This is due to a concentric depression near the steep mantle (Tomas 1997). In valve view a prominant hyaline area at the centre of the valve is visible with wide interstrae radiating from it, resulting in an irregular fasciculation. Hyaline lines are more conspicuous on the valve mantle than the valve face. Areolae are small. Cribra are visible with LM Two rings of small processes are located in the area between valve face and mantle. The outer ring contains two larger processes that are 120-180 degrees apart (Tomas 1997). Numerous small, irregular chloroplasts are present

Their distribution has been noted in European shelf seas. It is a significant member of the diatom community in the North-East Atlantic.