Chaetophora is a branched filamentous alga wholly embedded in mucilage. The species shown forms pads which can grow large enough to be visible to the naked eye as green, jelly globes adhered to stones or plants. The mucilage is a protection against ingestion. On the surface of this jelly globes one can see a lot of colorless cells formed as hairs (chaetae) projecting out of the jelly. This cells contain no chloroplasts and serve for nutrient uptake.
The bright field photo doesn´t display the mucilage. This young specimen showed only two projecting cells (see inserted picture). The arrow idicates a pyrenoid within a chloroplast.
Collected from Bodden, the brackish waters lying between the isles of Hiddensee and Ruegen (German Baltic Sea). This image was taken using Zeiss Universal with Olympus C7070 CCD camera.