diatomeiden

Diatoms are a major group of algae, specifically unicellular or colonial protists, found in almost every aquatic environment, including the oceans, freshwater lakes, and even damp soil. They are characterized by their unique cell walls, called frustules, which are made of silica. These frustules are remarkably intricate and are often described as glassy or jewel-like. Each frustule is composed of two overlapping halves, a valve and a girdle band. The patterns and shapes of these frustules vary widely among different diatom species, making them useful for identification.

Diatoms play a crucial role in ecosystems. They are primary producers, meaning they convert light energy into chemical energy through photosynthesis, forming the base of many aquatic food webs. Their photosynthetic activity also contributes significantly to the Earth's oxygen production. When diatoms die, their silica frustules sink to the bottom of water bodies, accumulating over time to form diatomaceous earth, a soft, porous, white or off-white sedimentary rock. This material has numerous commercial applications, including as a filtration medium, a mild abrasive in polishes, and an absorbent in cat litter. The study of diatoms is known as diatomology.