Algae Gallery

Art of Diatom algae (from Ernst Haeckel)

Diatoms. Computer-enhanced engraving of assorted species of diatom. Diatoms are a group of single- celled algae. The two main morphological types of diatom are represented here: pennate (rod-shaped) and centric (rounded). A characteristic feature of diatoms is their intricately patterned, glass-like cell wall, or frustule. The frustule consists of two halves which fit together like the lid and bottom of a box. It is often decorated with rows of tiny holes, known as striae. Diatoms form an important part of the floating plankton in the marine and freshwater food chains. Engraving taken from Ernst Haeckel's famous treatise: "Art Forms of Nature" (1904)

© MEHAU KULYK/SCIENCE PHOTO LIBRARY

Microcystis blue-green alga

Blue-green algae. Coloured transmission electron micrograph of a single cell of the blue-green algae Microcystis aeruginosa (also known as Anacystis cyanea). Blue-green algae (cyanobacteria) are primitive algae; in structure they are related to bacteria. They are prokaryotes containing no membrane-bound nucleus; instead, as in bacteria, nuclear material is dispersed throughout the cell. Photosynthetic lamellae (thread-like structures, outer part of cell) are the primitive chloroplasts. M.aeruginosa cells are found in colonies; they bloom in late summer and may liberate a toxin that kills plankton, fish and birds. Magnification: x16, 320 at 6x6cm size

© A.B. DOWSETT/SCIENCE PHOTO LIBRARY

SEM of diatoms and blue-green algae

Diatoms & blue-green algae. Coloured scanning electron micrograph (SEM) of groups of Navicula sp. diatoms (brown). Also seen in the image are strands of blue-green algae (blue). Diatoms are single celled algae that exist in huge numbers in marine and freshwater environments. Each diatom has an intricately patterned cell wall, or frustule, made of silica and pectin. The wall is in two halves which fit neatly together. They are a major constituent of plankton. As such, they are of great importance to the food chains in their environment. Blue-green algae or cyanobacteria are linear colonies of single-celled organisms. Magnification: x610 at 6x7cm size

© POWER AND SYRED/SCIENCE PHOTO LIBRARY